Chapter 1—The Foundations of Chemistry MULTIPLE CHOICE 1. Which of the following statements is incorrect? a. A body in motion possesses kinetic energy because of its motion. b. An object possesses potential energy because of its position or composition. c. Nuclear energy is an important kind of potential energy. d. Chemical reactions and physical changes that release energy to their surroundings are endothermic. e. The Law of Conservation of Matter and Energy states that the combined amount of matter and energy in the universe is fixed. ANS: D OBJ: Define the Laws of Conservation of matter and energy. | Define the terms endothermic and exothermic. | Classify energy as potential or kinetic. TOP: Matter and Energy 2. A braking automobile converts kinetic energy into heat in the brake pads. This is an example of the: a. law of conservation of energy b. law of constant composition c. law of conservation of matter d. law of multiple proportions e. law of gravity ANS: A OBJ: Apply the law of conservation of energy. TOP: Matter and Energy 3. When magnesium is burned in air the mass of the product is heavier than the original mass of the magnesium. However, the product formed still has the same exact mass of magnesium with the remainder of the mass being oxygen. This is an example of: a. law of conservation of energy b. law of definite proportions c. law of conservation of matter d. law of multiple proportions e. law of gravity ANS: C OBJ: Apply the law of conservation of energy. TOP: Matter and Energy 4. Which of the following represents matter that could be described as macroscale? a. a bromine atom b. molecules of water c. bacteria observed under a microscope d. a paperclip e. none of these ANS: D OBJ: Classify a description of matter as atomic-, micro-, or macro-scale. TOP: Chemistry – A Molecular View of Matter
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5. Dalton's Atomic Theory included all of the ideas listed below except: a. Atoms cannot be created or destroyed. b. An element is composed of very small particles called protons, neutrons and electrons. c. All atoms of a given element have identical properties. d. All atoms of a given element have properties that differ from those of other elements. e. Compounds are formed when atoms of different elements combine with one another in small whole-number ratios. ANS: B OBJ: Identify the tenets of Dalton's atomic theory. TOP: Chemistry – A Molecular View of Matter 6. Atoms consist of three fundamental particles. What are these particles and their charges? a. proton (+1), neutron (neutral) and electron (1) b. proton (1), neutron (+1) and electron (neutral) c. proton (+1), neutron (1) and electron (neutral) d. proton (neutral), neutron (+1) and electron (1) e. proton (1), neutron (neutral) and electron (+1) ANS: A OBJ: Identify the three subatomic particles that make up an atom. TOP: Chemistry – A Molecular View of Matter 7. One of the following does not describe gases. Which one is it? a. Expands infinitely. b. Rigid shape. c. Easily compressed. d. Relatively low densities. e. Particles far apart. ANS: B OBJ: Classify a gas. TOP: States of Matter 8. One of the following does not describe solids. Which one is it? a. Particles in definite positions. b. Definite shape. c. Easily compressed. d. Relatively high densities. e. Particles compact. ANS: C OBJ: Classify a solid. TOP: States of Matter 9. Which response lists characteristics of liquids? I. Volume does not vary much upon heating. II. Shape is constant. III. Easily compressed. IV. Fills the container completely. V. Flows.
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a. b. c. d. e.
I, III, IV, and V II, III, and V I I, II, IV, and IV I and V
ANS: E OBJ: Classify a liquid. TOP: States of Matter 10. All of the following are properties of antimony. Which one is not a physical property? a. It is a solid at room temperature. b. It has both yellow and gray forms (allotropes) in the solid state. c. It burns in an atmosphere of chlorine. d. It is one of the few substances that expands upon freezing. e. The gray form melts at 631C. ANS: C OBJ: Classify a property as physical or chemical. TOP: Chemical and Physical Properties 11. The following properties describe zinc. Which one(s) is (are) chemical properties? I. It is bluish-white metal. II. It corrodes upon prolonged contact with moist air. III. Its density is 7.14 g/cm3. IV. It melts at 419C. V. It conducts electricity. a. b. c. d. e.
IV and V IV V II, IV, and V II
ANS: E OBJ: Classify a property as physical or chemical. TOP: Chemical and Physical Properties 12. All of the following are properties of oxygen. Which one is a physical property? a. It supports combustion. b. It condenses to a liquid at 219C and atmospheric pressure. c. It causes iron to rust. d. It reacts with calcium to produce calcium oxide, CaO. e. All of these are physical properties. ANS: B OBJ: Classify a property as physical or chemical. TOP: Chemical and Physical Properties
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13. The following statements describe some physical and chemical properties of sucrose (table sugar). Which response includes all that describe chemical properties, and none that describe physical properties? I. It is a colorless solid. II. It chars or blackens when heated gently. III. Its density is 1.6 g/mL. IV. It ignites and burns with a yellow flame when heated strongly. V. It is usually in the form of small crystals although it can occur as a powder. a. b. c. d. e.
I, III, and IV II and IV II, IV, and V I and V another combination is the answer
ANS: B OBJ: Classify a property as physical or chemical. TOP: Chemical and Physical Properties 14. Which of the following is not an intensive property of matter? a. color b. density c. melting point d. weight e. boiling point ANS: D OBJ: Classify a property as intensive or extensive. TOP: Chemical and Physical Properties 15. Which of the following is an extensive property of matter? a. weight b. melting point c. specific gravity d. color e. density ANS: A OBJ: Classify a property as intensive or extensive. TOP: Chemical and Physical Properties 16. Identify which of the following properties of methane would be observed only with a change in composition. a. The melting point is 182.5C. b. The density is 6.67 104 g/cm3. c. Carbon dioxide forms when it burns. d. The boiling point is 161.5C. e. It dissolves slightly in water. ANS: C OBJ: Classify a property as chemical or physical. TOP: Chemical and Physical Properties
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17. Which response includes all of the following that involve chemical changes, and none that involve physical changes? I. converting milk to cheese II. converting water to steam III. composting leaves IV. burning of gasoline V. melting wax a. b. c. d. e.
II and V I, III, and IV I, II, and III IV and V III, IV, and V
ANS: B OBJ: Classify a property as chemical or physical. TOP: Chemical and Physical Changes 18. Which answer includes all of the following that are physical changes and no chemical changes? I. the electrolysis of molten sodium chloride to produce metallic sodium and gaseous chlorine II. the solidification of mercury by cooling III. the reaction of hydrochloric acid with calcium carbonate IV. the mixing of water with ethyl alcohol V. cutting an iron bar into small pieces a. b. c. d. e.
I and III II, IV, and V I and IV II, III, and V IV
ANS: B OBJ: Classify a property as chemical or physical. TOP: Chemical and Physical Changes 19. Which of these physical changes would require the liberation of energy? a. condensation of steam to form liquid water b. melting of ice c. boiling of water d. all of these e. none of these ANS: A OBJ: Identify physical changes as endothermic or exothermic. TOP: Chemical and Physical Changes 20. Which of the following changes in water represents a chemical change? a. Melting of ice. b. Boiling water. c. Sublimation of solid ice directly to gaseous water. d. Electrolyzing water to produce hydrogen and oxygen. e. Heating water from 25C to 60C.
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ANS: D OBJ: Classify changes as chemical or physical. TOP: Chemical and Physical Changes 21. Which answer lists all the substances below that are compounds and not any elements or mixtures? I ethanol II. neon III. bromine IV. water V. crude oil a. b. c. d. e.
I, II, and III I, IV, and V IV and V II, III, and V I and IV
ANS: E OBJ: Classify a substance as an element, compound, or mixture. TOP: Mixtures, Substances, Compounds, and Elements 22. Which of the following is not a mixture? a. air b. steel c. soda d. gasoline e. nitrogen ANS: E OBJ: Distinguish between examples of pure substances and mixtures. TOP: Mixtures, Substances, Compounds, and Elements 23. Crude oil can be separated into gasoline, diesel, heating oil, etc. by differences in boiling points. The form of matter which would best describe crude oil is: a. homogeneous mixture b. heterogeneous mixture c. compound d. mineral e. element ANS: A OBJ: Classify matter. TOP: Mixtures, Substances, Compounds, and Elements 24. Which statement is false? a. A compound is a substance that can be decomposed by chemical means into simpler substances. b. All samples of a particular pure substance have the same composition and properties. c. An example of a homogeneous mixture is one prepared by mixing two liquids, ethyl alcohol (grain alcohol) and water. d. An example of a heterogeneous mixture is one prepared by dissolving the solid, sodium chloride (table salt), in the liquid, water. e. Different mixtures of the same two substances can have different compositions.
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ANS: D OBJ: Define elements, compounds, or mixtures. | Classify matter. TOP: Mixtures, Substances, Compounds, and Elements 25. Which of the following is a compound? a. cola b. air c. mercury d. gasoline e. calcium fluoride ANS: E OBJ: Identify elements, compounds, and mixtures. TOP: Mixtures, Substances, Compounds, and Elements 26. Which mixture is incorrectly labeled? a. homogeneous / sugar dissolved in water b. homogeneous / sand stirred into water c. heterogeneous / orange juice with pulp d. heterogeneous / chocolate chip cookie e. heterogeneous / concrete sidewalk ANS: B OBJ: Classify a mixture as homogeneous or heterogeneous. TOP: Mixtures, Substances, Compounds, and Elements 27. A sample of matter that can be decomposed into three different elements a. must be a solution. b. must be a compound. c. must be a heterogeneous mixture. d. must be a homogeneous mixture. e. could be any of these answers. ANS: E OBJ: Classify matter. TOP: Mixtures, Substances, Compounds, and Elements 28. A form of matter is isolated and tested. No physical procedures can produce simpler forms of matter but heating the sample produces mercury and oxygen. The sample of matter must be: a. element b. compound c. solution d. mixture e. molecule ANS: B OBJ: Classify matter. TOP: Mixtures, Substances, Compounds, and Elements 29. What is the symbol for the element potassium? a. K b. P c. Pt d. W e. Po Whitten 10e
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ANS: A OBJ: Identify the symbol representing an element. TOP: Mixtures, Substances, Compounds, and Elements 30. The element whose symbol is Ca is a. carbon. b. cadmium. c. calcium. d. californium. e. none of these. ANS: C OBJ: Identify an element name given the symbol. TOP: Mixtures, Substances, Compounds, and Elements 31. What is the symbol for the element magnesium? a. Mg b. Fe c. Mn d. Mo e. Hg ANS: A OBJ: Identify the symbol representing an element. TOP: Mixtures, Substances, Compounds, and Elements 32. Which element / symbol pair is incorrect? a. Fe / iron b. Ca / calcium c. Ag / gold d. Pb / lead e. O / oxygen ANS: C OBJ: Identify the incorrect symbol/element name combination. TOP: Mixtures, Substances, Compounds, and Elements 33. Identify which of the following statements about elements and their abundance is false? a. Each element has its own unique symbol. b. Oxygen and silicon are very common. c. More than 99% of the Earth's mass is made up of only 10 of the naturally occurring elements. d. Most elements occur in nature as free elements, not in compounds. e. Gold is very uncommon. ANS: D OBJ: Know the qualitative abundance of the elements, the form of their occurrence in nature, and the terminology of the periodic table. TOP: Mixtures, Substances, Compounds, and Elements
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34. What is the symbol for the element strontium? a. Si b. S c. Sr d. Se e. Sm ANS: C OBJ: Identify the symbol representing an element. TOP: Mixtures, Substances, Compounds, and Elements 35. The element whose symbol is Br is a. boron. b. barium. c. bromine. d. berkelium. e. beryllium. ANS: C OBJ: Identify the element name given the symbol. TOP: Mixtures, Substances, Compounds, and Elements 36. The element whose symbol is Sn is a. silver. b. sulfur. c. tin. d. samarium. e. strontium. ANS: C OBJ: Identify the element name given the symbol. TOP: Mixtures, Substances, Compounds, and Elements 37. Which symbol / name combination is incorrect? a. Mn / manganese b. Zn / zinc c. Sn / tin d. Sr / strontium e. Pd / lead ANS: E OBJ: Identify the incorrect symbol/element name combination. TOP: Mixtures, Substances, Compounds, and Elements 38. Which name / symbol combination is incorrect? a. aluminum / Al b. cadmium / Ca c. cobalt / Co d. magnesium / Mg e. chromium / Cr ANS: B OBJ: Identify the incorrect symbol/element name combination. TOP: Mixtures, Substances, Compounds, and Elements
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39. Water is always 11.1% hydrogen and 88.9 % oxygen by mass. This is a statement of the a. Law of Conservation of Matter. b. Law of Definite Proportions. c. Law of Multiple Proportions. d. Law of Conservation of Matter and Energy. e. none of these. ANS: B OBJ: Identify the Law represented by percent mass of a pure compound. TOP: Mixtures, Substances, Compounds, and Elements 40. Below is a list of physical properties and the fundamental unit used in the SI system to measure each. Which unit is not the correct fundamental unit for the property?
a. b. c. d. e.
physical property / unit length / meter time / second mass / gram temperature / kelvin electric current / ampere
ANS: C OBJ: Identify the incorrect physical property/ fundamental SI unit combination. TOP: Measurements in Chemistry 41. Which of the following is not an SI system unit of measurement? a. seconds b. joules c. kelvins d. meters e. pounds ANS: E OBJ: Recognize SI and non-SI units of measurement. TOP: Measurements in Chemistry 42. Below is a list of common prefixes used in the SI and metric systems. Included with each is an abbreviation and meaning. Which set contains an error? a. mega- M 106 b. decid 101 c. centi- c 102 d. micro- m 106 e. kilok 103 ANS: D OBJ: Recognize common measurement prefixes, and their abbreviation and meaning. TOP: Measurements in Chemistry 43. Below is a list of common prefixes used in the SI and metric systems. Included with each is an abbreviation and meaning. Which set contains an error? a. mega- M 106 b. decid 101 c. nano- n 109 d. milli- m 103 e. kilok 103 Whitten 10e
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ANS: A OBJ: Recognize common measurement prefixes, and their abbreviation and meaning. TOP: Measurements in Chemistry 44. Which of the following is equivalent to 10 cm? a. 1 m b. 0.1 dm c. 100 mm d. 1000 m e. 1 mm ANS: C OBJ: Express a measurement in different units. TOP: Measurements in Chemistry 45. One of the following is a reasonable approximation of the diameter of a quarter (U.S. coin). Which one? a. 24 Mm b. 0.24 m c. 24 mm d. 24 cm e. 0.0024 km ANS: C OBJ: Approximate a measurement and express it in a variety of common units. TOP: Units of Measurement 46. The mass of an average adult male would be closest to? a. 82 kg b. 100 lbs c. 28 kg d. 280 lbs e. 8200 g ANS: A OBJ: Approximate a measurement and express it in a variety of common units. TOP: Units of Measurement 47. A bug travels at a speed of 1 cm/s. The notation cm/s could also be written as: a. cm s b. cm1 s1 c. cm1 s d. cm s1 e. none of these. ANS: D OBJ: Know the different ways to express units found in the denominator of a measurement. TOP: Units of Measurement 48. Which of the following numbers has 4 significant figures? a. 0.04309 b. 0.0430 c. 0.0431 d. 0.43980 e. 0.043090 Whitten 10e
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ANS: A OBJ: Identify the measurement with the stated number of significant figures. TOP: Use of Numbers 49. The sum 2.834 + 5.71520 + 2.12 + 178.1 + 250.2619 expressed to the proper number of significant figures is: a. 439 b. 439.0 c. 439.03 d. 439.031 e. 439.0311 ANS: B OBJ: Express a measurement derived from a calculation with the correct precision by applying the significant figure rules for calculations. TOP: Use of Numbers 50. Perform the indicated mathematical operations and express the answer in scientific notation rounded off to the proper number of significant figures: (8.001 102) (2.88 103 2.4 103) = a. b. c. d. e.
9.6 102 9.60 108 9.601 108 9.6 108 9.6 102
ANS: D OBJ: Express a value in scientific notation. | Express a measurement derived from a calculation with the correct precision by applying the significant figure rules for calculations. TOP: Use of Numbers 51. The answer to the following calculation, rounded to the proper number of significant digits, is: 23.413 g (2.15 cm 1.1 cm 3.73 cm) a. b. c. d. e.
2.654 g/cm3 2.65 g/cm3 2.7 g/cm3 3.0 g/cm3 2.66 g/cm3
ANS: C OBJ: Express a measurement derived from a calculation with the correct precision by applying the significant figure rules for calculations. TOP: Use of Numbers 52. How many millimeters are there in 25 feet? a. 7.6 102 mm b. 2.6 103 mm c. 1.0 102 mm d. 7.6 103 mm e. 1.2 103 mm
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ANS: D OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 53. What is the height in centimeters of a person who is 5 feet 10 inches tall? a. 1.8 104 cm b. 3.6 102 cm c. 27 cm d. 1.5 102 cm e. 1.8 102 cm ANS: E OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 54. If 5.76 1013 neon atoms (spherical) were laid in a line, each touching the next, the line would measure 2.54 miles. What is the diameter of a neon atom in Å? a. 0.92 Å b. 0.71 Å c. 1.86 Å d. 1.44 Å e. 1.74 Å ANS: B OBJ: Calculate a value using the data provided. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 55. Convert 25.2 kilometers to inches. a. 99.2 in b. 6.40 106 in c. 9.92 105 in d. 9.92 101 in e. 6.40 103 in ANS: C OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 56. Convert 175 milliliters to gallons. a. 0.0462 gal b. 0.0414 gal c. 0.740 gal d. 0.164 gal e. 0.660 gal ANS: A OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis)
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57. Express 39.34 square yards in square centimeters. a. 0.6417 cm2 b. 17280 cm2 c. 1.835 106 cm2 d. 3.289 105 cm2 e. 7.632 106 cm2 ANS: D OBJ: Express an area in different units. TOP: The Unit Factor Method (Dimensional Analysis) 58. What is the area in square millimeters of a rectangle that is 8.632 cm long and 26.41 mm wide? a. 2280 mm2 b. 3.060 mm2 c. 22.80 mm2 d. 0.3060 mm2 e. 30.60 mm2 ANS: A OBJ: Determine the area of an object. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 59. What is the area (in mm2) of a rectangular surface that is 0.640 inch wide and 1.14 inches long? a. 471 mm2 b. 328 mm2 c. 84.2 mm2 d. 242 mm2 e. 680 mm2 ANS: A OBJ: Determine the area of an object. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 60. What is 16.7 cubic feet expressed in cubic centimeters? a. 1.55 104 cm3 b. 510 cm3 c. 0.159 cm3 d. 1.76 103 cm3 e. 4.73 105 cm3 ANS: E OBJ: Determine the volume of an object. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 61. Express 21.5 cubic centimeters in quarts. a. 2.03 102 qt b. 2.26 104 qt c. 9.24 102 qt d. 2.27 102 qt e. 2.02 104 qt ANS: D OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis)
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62. Assuming a magnesium atom is spherical, calculate its volume in nm3. The diameter of a magnesium atom is 3.20 Å . The volume of a sphere is V = (4/3) r3. 1 Å = 1 1010 m and 1 nm = 1 109 m (Both of these relationships are exact). = 3.14. a. 5.57 103 nm3 b. 2.34 1022 nm3 c. 5.57 1024 nm3 d. 1.71 102 nm3 e. 5.57 103 nm3 ANS: D OBJ: Determine the volume of an object. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 63. Assuming that a lithium atom is spherical, calculate its volume in cm3. The volume of a sphere is given by V = (4/3) r3. The radius of a lithium atom is 1.52 Å. 1 Å = 108 cm and = 3.14. a. 4.78 108 cm3 b. 1.47 1023 cm3 c. 6.14 1022 cm3 d. 3.06 1017 cm3 e. 4.68 1024 cm3 ANS: B OBJ: Determine the volume of an object. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 64. How many kilograms of lead are there in 749 pounds of lead? a. 95.1 kg b. 340 kg c. 760 kg d. 28.0 kg e. 1650 kg ANS: B OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 65. What is the mass, in grams, of a 16.0 lb bowling ball? a. 7300 g b. 0.0352 g c. 7260 g d. 6520 g e. 8000 g ANS: C OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 66. It requires 2.26 103 J to boil 1 g H2O. How many kJ are required to boil 1.00 lb H2O? a. 1030 kJ b. 4.98 kJ c. 4980 kJ d. 201 kJ e. 2260 kJ
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ANS: A OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 67. If an airplane's speed is 550 mi/h, what is its speed in m/s? a. 40 m/s b. 328 m/s c. 246 m/s d. 528 m/s e. 885 m/s ANS: C OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 68. The mileage rating of a new high efficiency automobile is 52.0 miles per gallon. This could also be expressed as ____ kilometers per liter. a. 28.2 b. 31.6 c. 22.0 d. 72.6 e. 83.6 ANS: C OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 69. The 1970 standard established by the U.S. government for carbon monoxide emission for automobiles limited exhaust to 23.0 grams of CO per vehicle-mile. Assume that in a given metropolitan area there are 82,700 automobiles, driven an average of 13.5 miles per 24-hour period. How many tons/day of CO could legally be discharged into the area's atmosphere? a. 270 tons/day b. 0.155 tons/day c. 28.3 tons/day d. 0.0535 tons/day e. 39.0 tons/day ANS: C OBJ: Calculate a value using the data provided. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 70. At 25C, one milliliter of mercury has a mass of 13.6 grams. How many liters of mercury are required to have a mass of 500 kg of mercury? a. 500 L b. 25.2 L c. 42.1 L d. 13.6 L e. 36.8 L ANS: E OBJ: Calculate a value using the data provided. | Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis)
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71. Caffeine, a stimulant in coffee and some cola drinks, is 49.47% carbon, 5.19% H, 28.8% N, 16.48% O. What is the mass of carbon contained in 37.1 g of caffeine? a. 18.4 g b. 36.8 g c. 6.11 g d. 1840 g e. 24.3 g ANS: A OBJ: Determine the mass of a component in a substance using percent mass. TOP: Percentage 72. Dark dental 22 carat gold is an alloy consisting of 92% Au, 4.9% Ag, and 3.1% Cu. If a patient leaves the dentist's office with 3.25 g of dark dental gold in her mouth, what mass of each element does she have in her mouth? (Note: round off may result in total mass not quite equaling 3.25 g.) a. 2.8 g Au 0.25 g Ag 0.15 g Cu b. 2.9 g Au 0.10 g Ag 0.16 g Cu c. 2.3 g Au 0.75 g Ag 0.20 g Cu d. 3.0 g Au 0.16 g Ag 0.10 g Cu e. 2.9 g Au 0.25 g Ag 0.10 g Cu ANS: D OBJ: Determine the mass of a component in a substance using percent mass. TOP: Percentage 73. A 125 g sample of calcium carbonate contains 50.1 g calcium, 15.0 g carbon, and 59.9 g oxygen. Which of the following statements about calcium carbonate is incorrect? a. Calcium carbonate is 40.1 % calcium by mass. b. Calcium carbonate is 47.9 % oxygen by mass. c. Calcium carbonate is 15.0 % carbon by mass. d. Calcium carbonate has a smaller % by mass of carbon than of calcium. e. Calcium carbonate follows the Law of Definite Proportions. ANS: C OBJ: Determine the percent by mass of a component from its composition. | Identify the Law represented by percent mass of a pure compound. TOP: Percentage 74. A cube of metal is 1.42 centimeters on an edge. Its mass is 16.3 grams. What is its density? a. 4.68 g/cm3 b. 4.30 g/cm3 c. 5.69 g/cm3 d. 6.14 g/cm3 e. 4.86 g/cm3 ANS: C OBJ: Calculate density from mass and volume. TOP: Density and Specific Gravity
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75. A metal cube having a mass of 112 grams is dropped into a graduated cylinder containing 30.00 mL of water. This causes the water level to rise to 39.50 mL. What is the density of the cube? a. 2.86 g/mL b. 11.8 g/mL c. 10.8 g/mL d. 3.74 g/mL e. 10.6 g/mL ANS: B OBJ: Calculate total volume from liquid displacement data. | Calculate density from mass and volume. TOP: Density and Specific Gravity 76. What is the specific gravity of nickel if 2.35 cm3 of nickel has the same mass as 20.9 mL of water at room temperature? a. 0.112 b. 2.14 c. 8.89 d. 19.7 e. 49.2 ANS: C OBJ: Calculate the specific gravity of a substance. TOP: Density and Specific Gravity 77. The density of mercury is 13.6 g/cm3. What is the mass of 6.50 cm3 of mercury? a. 0.478 g b. 88.4 g c. 18.9 g d. 2.38 g e. 1.10 102 g ANS: B OBJ: Convert volume to mass using density. TOP: Density and Specific Gravity 78. A gold ring has a mass of 15.37 g. If this ring is pure gold (density = 16.1g/mL), what would the volume of the ring be? a. 15.37 mL b. 1.04 mL c. 0.955 mL d. 16.1 mL e. 8.05 mL ANS: C OBJ: Convert mass to volume using density. TOP: Density and Specific Gravity 79. The density of octane is 0.702 g/cm3. What is the mass of 65.0 mL of octane? a. 110 g b. 92.6 g c. 22.5 g d. 45.6 g e. 1.08 102 g
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ANS: D OBJ: Convert volume to mass using density. | Express a measurement in different units. TOP: Density and Specific Gravity 80. The specific gravity of ethyl chloride, an external painkiller, is 1.37 at 10C. What is the mass of 47.4 mL of the liquid? a. 64.9 g b. 0.346 g c. 34.6 g d. 52.5 g e. 56.6 g ANS: A OBJ: Convert volume to mass using specific gravity. TOP: Density and Specific Gravity 81. What is the volume of a 2.50-gram block of metal whose density is 6.72 grams per cubic centimeter? a. 16.8 cm3 b. 2.69 cm3 c. 0.0595 cm3 d. 0.372 cm3 e. 1.60 cm3 ANS: D OBJ: Convert mass to volume using density. TOP: Density and Specific Gravity 82. What volume is occupied by 14.3 g of mercury? Density = 13.6 g/mL. a. 37.2 mL b. 0.236 mL c. 193 mL d. 1.05 mL e. 4.82 mL ANS: D OBJ: Convert mass to volume using density. TOP: Density and Specific Gravity 83. What is the volume of a 58.5 gram sample of a liquid with a specific gravity of 1.24? a. 47.2 mL b. 63.2 mL c. 72.8 mL d. 20.2 mL e. 35.2 mL ANS: A OBJ: Convert mass to volume using specific gravity. TOP: Density and Specific Gravity
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84. A saltwater aquarium should have a specific gravity of approximately 1.07. What is the density of seawater? a. 1.07 g/mL b. 10.7 g/mL c. 1.00 g/mL d. 0.935 g/mL e. 0.00107 g/mL ANS: A OBJ: Determine the density of a solution from its specific gravity. TOP: Density and Specific Gravity 85. Bromine, a brick red liquid, has a specific gravity of 3.12. What is the mass of 25.6 mL of bromine? a. 8.21 g b. 39.9 g c. 82.1 g d. 79.9 g e. 7.99 g ANS: D OBJ: Convert volume to mass using specific gravity. TOP: Density and Specific Gravity 86. Which of the following statements about density is incorrect? a. The densities of gases are usually expressed in units of g/L. b. The intensive property density can be calculated from the two extensive properties: mass and volume. c. The densities of liquids are usually expressed in units of g/mL (or g/cm3). d. If oil and water are placed in a container, they form two layers with oil as the top layer because it has the greater density. e. Densities of gases change greatly with changes in temperature and pressure. ANS: D OBJ: Understand the effect of temperature on density. | Know the units of density. | Understand the effect of pressure on density. | Understand how density effects layering of immiscible substance. TOP: Density and Specific Gravity 87. The freezing point of argon is 189C. What is its freezing point on the absolute temperature scale? a. 84 K b. 136 K c. 461 K d. 112 K e. 72 K ANS: A OBJ: Convert degrees Celsius to kelvins. TOP: Heat and Temperature 88. Liquid propane boils at 231K. What is its boiling point in C? a. 42C b. 315C c. 42C d. 504C e. 231C Whitten 10e
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ANS: C OBJ: Convert kelvins to degrees Celsius. TOP: Heat and Temperature 89. Methane, CH4, boils at 162C. What is the boiling point of methane in F? a. 58F b. 108F c. 260F d. 323F e. 464F ANS: C OBJ: Convert degrees Celsius to degrees Fahrenheit. TOP: Heat and Temperature 90. Tungsten melts at 3422C which is why it is used as the filament in incandescent lights. What is its melting temperature in F? a. 1933F b. 1901F c. 619F d. 6150F e. 6192F ANS: E OBJ: Convert degrees Celsius to degrees Fahrenheit. TOP: Heat and Temperature 91. If normal body temperature is 98.6F, what is normal body temperature in C? a. 45.0C b. 37.0C c. 20.0C d. 52.6C e. 25.6C ANS: B OBJ: Convert degrees Fahrenheit to degrees Celsius. TOP: Heat and Temperature 92. The freezing point of the noble gas, argon, is 308F. What is this temperature in kelvins? a. 120 K b. 462 K c. 249 K d. 84 K e. 462 K ANS: D OBJ: Convert degrees Fahrenheit to degrees Celsius. | Convert degrees Celsius to kelvins. TOP: Heat and Temperature
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93. Heptane melts at 182 K, and it boils at 371K. Which statement below is incorrect? a. Heptane will be a liquid at room temperature. b. The melting point of heptane is 132F. c. The melting point of heptane is lower than the melting point of water. d. Heptane would be a solid in a 200 K room. e. Heptane would be a solid at 100 K. ANS: D OBJ: Understand melting point. | Understand boiling point. | Convert kelvins to degrees Celsius. | Convert degrees Celsius to degrees Fahrenheit. TOP: Heat and Temperature 94. Gallium, a metal, has a freezing point near room temperature so it can be melted by holding it in your hands. If gallium's melting point is 302.8 K, what is that temperature in C? a. 0.0C b. 575.8C c. 302.8C d. 39.8C e. 29.8C ANS: E OBJ: Convert kelvins to degrees Celsius. TOP: Heat and Temperature 95. What is the boiling point of liquid nitrogen, 77 K, on the Fahrenheit scale? a. 321F b. 171F c. 168F d. 14.0F e. 144F ANS: A OBJ: Convert kelvins to degrees Celsius. | Convert degrees Celsius to degrees Fahrenheit. TOP: Heat and Temperature 96. Which of the following are sets of equivalent temperatures? I. 278 K 77F 25C II. 303 K 86F 30C III. 363 K 194F 90C IV. 251 K 68F 22C a. b. c. d. e.
I and II II and III I and III II and IV III and IV
ANS: B OBJ: Convert between three temperature units:degrees Fahrenheit, degrees Celsius, and kelvins. TOP: Heat and Temperature
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97. How many kilojoules are equivalent to 565 calories? a. 130 kJ b. 930 kJ c. 0.135 kJ d. 2.36 kJ e. 2360 kJ ANS: D OBJ: Convert calories to kJ. TOP: Heat Transfer and the Measurement of Heat 98. How much heat is released as the temperature of 25.2 grams of iron is decreased from 72.1C to 9.8C? The specific heat of iron is 0.444 J/gC. a. 113 J b. 566.1 J c. 1.11 kJ d. 0.697 kJ e. 957 J ANS: D OBJ: Calculate the change in temperature of a substance. | Calculate the heat released based on the temperature change of a substance. TOP: Heat Transfer and the Measurement of Heat 99. The specific heat of aluminum is 0.900 J/gC. How many joules of heat are absorbed by 15.0 g of Al if it is heated from 20.0C to 60.0C? a. 540 J b. 270 J c. 812 J d. 2.40 J e. 1.17 104 J ANS: A OBJ: Calculate the change in temperature of a substance. | Calculate the heat released or gained based on the temperature change of a substance. TOP: Heat Transfer and the Measurement of Heat 100. An endothermic reaction a. evolves heat. b. is also called exothermic. c. would have its heat transferred measured in Joules. d. is not possible. e. would be described by all of these. ANS: C OBJ: Know the units of energy. | Define the terms endothermic and exothermic. TOP: Heat Transfer and the Measurement of Heat 101. An exothermic reaction a. absorbs heat. b. is also called kinetic. c. is not possible. d. would have its heat transferred measured in Joules. e. would be described by all of these.
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ANS: D OBJ: Know the units of energy. | Define the terms endothermic and exothermic. TOP: Heat Transfer and the Measurement of Heat 102. If 10.0 g of copper cools from 35.0C to 28.8C and loses 23.6 joules of heat, what is the specific heat of copper? a. 0.076 J/gC b. 3.8 102 J/gC c. 0.38 J/gC d. 0.62 J/gC e. 76 J/gC ANS: C OBJ: Calculate the change in temperature of a substance. | Calculate the specific heat of a substance based on the change in heat content and the temperature change of the substance. TOP: Heat Transfer and the Measurement of Heat 103. What is the specific heat of a 5.75 g piece of metal if the addition of 175 joules of heat causes a 22.3C temperature increase? a. 1.36 J/gC b. 4.18 J/gC c. 1.11 J/gC d. 0.73 J/gC e. 1.54 J/gC ANS: A OBJ: Calculate the specific heat of a substance based on the change in heat content and the temperature change of the substance. TOP: Heat Transfer and the Measurement of Heat 104. A 10.0 kg piece of metal at 50.0C is placed in 1000. g of water at 10.0C in an insulated container. The metal and water come to the same temperature at 30.6C. What is the specific heat of metal? The specific heat of water is 4.18 J/gC. a. 0.0686 J/gC b. 0.444 J/gC c. 0.721 J/gC d. 0.124 J/gC e. 0.0216 J/gC ANS: B DIF: Harder Question OBJ: Calculate the specific heat of a substance based on the temperature equilibration of two substances. | Express a measurement in different units. | Calculate the change in temperature of a substance. TOP: Heat Transfer and the Measurement of Heat
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105. The same amount of heat is added to a 25-g sample of each of the following metals. If each of the metals was initially at 20.0C, which metal will reach the highest temperature?
a. b. c. d. e.
Metal beryllium calcium copper gold nickel
Specific Heat 1.82 J/gC 0.653 J/gC 0.385 J/gC 0.129 J/gC 0.444 J/gC
ANS: D OBJ: Identify the substance with the greatest change in temperature. | Understand the relationship between the specific heat of a substance and the change in temperature of a substance. TOP: Heat Transfer and the Measurement of Heat 106. If 100. grams of liquid water at 100.0C and 200. grams of water at 20.0C are mixed in an insulated container, what will be the final temperature of the water? The specific heat of water is 4.18 J/gC. a. 41.9C b. 44.2C c. 46.7C d. 48.3C e. 45.1C ANS: C DIF: Harder Question OBJ: Calculate the equilibrium temperature of a mixture. TOP: Heat Transfer and the Measurement of Heat 107. How many grams of water at 25C must be mixed in an insulated container with 250. grams of water at 93C if the final temperature of the combined water is to be 75C? a. 45 g b. 376 g c. 120 g d. 90 g e. 140 g ANS: D OBJ: Calculate the mass of one substance required to cool another substance to a specified temperature. TOP: Heat Transfer and the Measurement of Heat 108. If a 10.0 g ball of iron at 160.0C is dropped into 50.0 g of water at 20.0C in an insulated container, what will be the final temperature of the water? The specific heat of iron is 0.444 J/gC and that of water is 4.18 J/gC. a. 23C b. 38C c. 48C d. 82C e. 110C ANS: A DIF: Harder Question OBJ: Calculate the equilibrium temperature of a mixture. TOP: Heat Transfer and the Measurement of Heat Whitten 10e
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109. One of the following does not describe gases. Which one is it? a. fills any container completely b. slight expansion on heating c. easily compressed d. relatively low densities e. particles far apart ANS: B OBJ: Classify a gas or solid. TOP: States of Matter 110. Which of the following is not an intensive property of matter? a. malleability b. boiling point c. thermal conductivity d. weight e. color ANS: D OBJ: Classify a property as intensive or extensive. TOP: Chemical and Physical Properties 111. Which of these physical changes would require the addition of energy? a. boiling a liquid b. condensing a gas c. freezing a liquid d. all of these e. none of these ANS: A OBJ: Identify the endothermic or exothermic physical change. TOP: Chemical and Physical Changes 112. Which of following represents a physical change? a. the decomposition of cinnabar (HgS) to mercury metal upon heating b. the electrolysis of water to produce hydrogen and oxygen c. the tarnishing of the surface of copper in the presence of oxygen d. the dissolution of sugar in water e. the rusting of iron ANS: D OBJ: Classify changes as chemical or physical. TOP: Chemical and Physical Changes 113. Which of the following is not a mixture? a. sea shells b. cow manure c. ice cream d. gasoline e. diamond ANS: E OBJ: Distinguish between examples of pure substances and mixtures. TOP: Mixtures, Substances, Compounds, and Elements
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114. Which of the following is a compound? a. soda b. air c. copper ore d. skim milk e. table salt ANS: E DIF: Hard OBJ: Distinguish between examples of pure substances and mixtures. TOP: Mixtures, Substances, Compounds, and Elements 115. What is the symbol for the element tin? a. Sn b. Ti c. S d. Zn e. K ANS: A OBJ: Identify the symbol representing an element. TOP: Mixtures, Substances, Compounds, and Elements 116. The element whose symbol is K is a. potassium. b. krypton. c. cobalt. d. calcium. e. none of these. ANS: A OBJ: Identify the symbol representing an element. TOP: Mixtures, Substances, Compounds, and Elements 117. Below is a list of physical properties and the fundamental unit used in the SI system to measure each. Which unit is not the correct fundamental unit for the property?
a. b. c. d. e.
physical property / unit amount of substance / mole luminous intensity / candela time / meter temperature / kelvin electric current / ampere
ANS: C OBJ: Identify the incorrect physical property/ fundamental SI unit combination. TOP: Measurements in Chemistry 118. What is the height in centimeters of a person who is 4 ft 10 in tall? (2.54 cm = 1 in; 1 ft = 12 in) a. 1.5 104 cm b. 2.9 102 cm c. 22 cm d. 1.2 102 cm e. 1.5 102 cm
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ANS: E OBJ: Express a measurement in different units. TOP: The Unit Factor Method (Dimensional Analysis) 119. Which of the following would you classify as nano-scale? a. An amoeba (one-celled animal) b. Coffee grounds c. A water molecule d. A cell membrane e. Gold ore ANS: C OBJ: Approximate the size-scale of matter. TOP: Chemistry – A Molecular View of Matter 120. Which of the following substances is an element? a. F2 b. C2H5OH c. Sodium chloride d. Water e. Brass ANS: A OBJ: Identify the element. TOP: Mixtures, Substances, Compounds, and Elements 121. Which of the following represents a mixture of two elements? a.
b.
c.
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d.
e.
ANS: D OBJ: Identify the mixture of two elements. TOP: Mixtures, Substances, Compounds, and Elements 122. What kind of change is depicted below?
a. Chemical change b. Physical change
c. Both chemical and physical change d. No change
ANS: A OBJ: Classify changes as chemical or physical. TOP: Chemical and Physical Changes 123. What kind of change is depicted below?
a. chemical change b. physical change
c. both chemical and physical d. no change
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ANS: C OBJ: Classify changes as chemical or physical. TOP: Chemical and Physical Changes 124. How many significant figures are there in the number 0.097 a. 1 b. 2 c. 3 d. 4
e. 5
ANS: B OBJ: Identify the number of significant figures in a measurement. TOP: Use of Numbers 125. How many significant figures are there in the number 75100 a. 1 b. 2 c. 3 d. 4
e. 5
ANS: C OBJ: Identify the number of significant figures in a measurement. TOP: Use of Numbers 126. How many significant figures are there in the number 1.0720 a. 1 b. 2 c. 3 d. 4
e. 5
ANS: E OBJ: Identify the number of significant figures in a measurement. TOP: Use of Numbers 127. How many significant figures are there in the number 0.0306960? a. 4 b. 5 c. 6 d. 7
e. 8
ANS: C OBJ: Identify the number of significant figures in a measurement. TOP: Use of Numbers 128. What is the best answer to report for (515 x 0.0025) + 24.57? a. 25.858 b. 25.86 c. 25.8575 d. 26
e. 25.9
ANS: E OBJ: Report the answer in a mixed operation to the correct number of significant figures. TOP: Use of Numbers 129. When 87.7 is added to 73.841, the result should be reported with _____ significant figures.
And when 87.7 is divided by 73.841 the result should be reported with ______ significant figures. a. 3, 3 b. 3, 5 c. 4, 3 d. 4, 4 e. 3, 4 ANS: C OBJ: Determine the number of significant figures for the given operations. TOP: Use of Numbers 130. When 45.24 is subtracted from 40.1, the result should have _____ sig figs. When 45.24 is
multiplied by 40.1, the result should have _____ sig figs. a. 2 , 5 b. 3 , 3 c. 2 , 3 d. 4 , 4
e. 3 , 2
ANS: C OBJ: Determine the number of significant figures for the given operations. TOP: Use of Numbers Whitten 10e
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131. When 51.8 and 67.5 are multiplied, the product has ____ significant figures, and when 51.8
and 67.5 are added, the sum has ____ significant figures. a. 5 , 3 b. 3 , 4 c. 3 , 5 d. 4 , 3
e. 3 , 3
ANS: B OBJ: Determine the number of significant figures for the given operations. TOP: Use of Numbers 132. Which is higher: 144oF or 63.6oC? a. 144oF b. 63.6oC
{ oF = 9/5(oC) + 32 } c. The temperatures are equivalent
ANS: B OBJ: Compare two temperatures in different units. TOP: Heat and Temperature 133. As part of the calibration of a new laboratory balance, a 0.200-g mass is weighed with the
following results: Trial Mass 1 0.216-g 2 0.196-g 3 0.187-g Choose the statement that best describes the calibration data. a. b. c. d.
The balance is both accurate and precise. The balance is accurate but imprecise. The balance is precise but inaccurate. The balance is both inaccurate and imprecise.
ANS: B OBJ: Interpret the accuracy and precision of a set of data. TOP: Accuracy and Precision 134. The liquid 1,2-ethanedithiol is insoluble in water. If a 75.5 g sample of 1,2-ethanedithiol has
a volume of 61.2 mL, what is its density, and would it float or sink if poured into a beaker containing water? a. 1.20g/mL and it would sink in water c. 0.811 g/mL and it would sink in water b. 1.20 g/mL and it would float on water d. 0.811 g/mL and it would float on water ANS: A OBJ: Calculate the density and determine if the substance floats or sinks. TOP: Density 135. An empty Erlenmeyer flask weighs 241.3g. When filled with water (density = 0.997g/mL),
the flask and its contents weigh 489.1g. What volume of water does the flask hold? a. 246.3 mL b. 247.1 mL c. 247.8 mL d. 248.5 mL e. 240.6 mL ANS: D OBJ: Calculate a volume given density and mass. TOP: Density
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SHORT ANSWER
Instructions: Use the pictures below to answer the following questions:
A)
B)
D)
E)
C)
1. Which of the figures above depicts a heterogeneous mixture? ANS: B OBJ: Identify the heterogeneous mixture. TOP: Mixtures, Substances, Compounds, and Elements 2. Which of the figures above depicts a liquid compound? ANS: E OBJ: Identify the liquid compound. TOP: States of Matter | Mixtures, Substances, Compounds, and Elements 3. Which of the figures above depicts a gaseous compound? ANS: D OBJ: Identify the gaseous compound. TOP: States of Matter | Mixtures, Substances, Compounds, and Elements 4. Which of the figures above depicts a homogeneous mixture? ANS: C OBJ: Identify the homogeneous mixture. TOP: Mixtures, Substances, Compounds, and Elements
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Instructions: Use the figures below to answer the following questions:
A)
B)
D)
E)
C)
5. Which of the figures above represents a gaseous compound? ANS: B OBJ: Identify the gaseous compound. TOP: States of Matter | Mixtures, Substances, Compounds, and Elements 6. Which of the figures above represents a liquid element? ANS: D OBJ: Identify the liquid element. TOP: States of Matter | Mixtures, Substances, Compounds, and Elements 7. Which of the figures above represents a homogeneous mixture? ANS: E OBJ: Identify the homogeneous mixture. TOP: Mixtures, Substances, Compounds, and Elements 8. Which of the figures above represents a gaseous element? ANS: A OBJ: Identify the gaseous element. TOP: States of Matter | Mixtures, Substances, Compounds, and Elements 9. Which of the figures above represents a liquid compound? ANS: C OBJ: Identify the liquid compound. TOP: States of Matter | Mixtures, Substances, Compounds, and Elements
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CONCEPTUAL 1. What are some experiments that might be performed to determine the identity of an unknown metal from the moon? OBJ: Propose an experiment to determine the density of a substance. TOP: Density 2. Why is having a universal system of units for the entire planet a good idea? Why does the United States still use other units? OBJ: Explain the value of a universal system of units. TOP: Units of Measurement | Measurements in Chemistry 3. If there are only about 88 naturally occurring type of atoms, why is there such a tremendous variety of matter in the universe? OBJ: Explain why matter is not limited to the 88 naturally occurring elements. TOP: Mixtures, Substances, Compounds, and Elements 4. A 50-lb rock is removed from the bottom of a pool and placed in a canoe on the surface of the pool. Does the water level in the pool increase or decrease? OBJ: Explain the effect of density with respect to liquid displacement. TOP: Density 5. What are some pure elements that we encounter every day? What are some pure compounds? OBJ: Classify a common substance as an element or a compound. TOP: Mixtures, Substances, Compounds, and Elements 6. If Einstein's equation E = mc2 is correct what happens when energy is released from a nuclear reaction? OBJ: Propose the fate of matter in a nuclear reaction. TOP: Nuclear reactions. | Matter and Energy
Chapter 2—Chemical Formulas and Composition Stoichiometry MULTIPLE CHOICE 1. There are two different common crystalline forms of carbondiamond and graphite. A less common form called fullerene, C60, also exists. Different forms of the same element in the same physical state are called: a. isotopes. b. isomers. c. alloforms. d. allotropes. e. structural formulas. ANS: D Whitten 10e
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OBJ: Define allotrope. TOP: Chemical Formulas 2. How many atoms are in a sulfuric acid molecule? a. 1 b. 7 c. 5 d. 6 e. 8 ANS: B OBJ: Know the chemical formulae of common acids. TOP: Chemical Formulas 3. If a sample of butane, C4H10, contains a total of 8.0 103 atoms of carbon, how many molecules of butane are in the sample? a. 6.0 103 b. 3.0 103 c. 8.0 103 d. 1.1 104 e. 2.0 103 ANS: E OBJ: Understand the relationship between molecular formula and the number of atoms of a specific type contained in a single compound. | Convert the number of atoms in a substance to the number of molecules in a substance. TOP: Chemical Formulas 4. Name the molecular compound, HNO3. a. ammonia b. nitric acid c. nitrous acid d. nitric oxide e. methane ANS: B OBJ: Know the names and chemical formulae of common acids. TOP: Chemical Formulas
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5. Name the molecular compound, SO3. a. sulfur oxide b. sulfurous acid c. sulfur trioxide d. sulfuric acid e. none of these ANS: C OBJ: Translate the chemical formula of a binary molecule into a name. TOP: Chemical Formulas 6. Which formula / name pair does not match? a. HNO3 / nitric acid, used to produce explosives b. CH3OH / methyl alcohol, wood alcohol c. CH3CH2OH / ethyl alcohol, alcohol in wine d. CHCl3 / acetic acid, found in vinegar e. CH3CH2OCH2CH3 / diethyl ether, an anesthetic ANS: D OBJ: Know the names and chemical formulae of common acids. | Recognize the names and chemical formulae of common organic compounds. TOP: Chemical Formulas 7. Name the molecular compound, CH3COCH3. a. acetone b. ethanol c. diethyl ether d. propane e. ethyl alcohol ANS: A OBJ: Know the names and chemical formulae of common organic compounds. TOP: Chemical Formulas 8. What is the molecular formula for ethanol? a. CH3COOH b. CH3COCH3 c. CH3CH2OCH2CH3 d. CH3CH2CO2H e. CH3CH2OH ANS: E OBJ: Know the names and chemical formulae of common organic compounds. TOP: Chemical Formulas 9. Butane, a highly combustible hydrocarbon found in disposable lighters, has the chemical formula: a. CO2 b. C4H8 c. C4H10 d. C3H8 e. CH3OCH3
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ANS: C OBJ: Know the names and chemical formulae of common organic compounds. | Translate the chemical formula of a binary molecule into a name. TOP: Chemical Formulas 10. What is the molecular formula for hydrogen chloride? a. HCl b. HClO c. HClO2 d. HClO3 e. HClO4 ANS: A OBJ: Know the names and chemical formulae of common acids. TOP: Chemical Formulas 11. A compound contains only calcium and fluorine. A sample of the compound is determined to contain 2.00 g of calcium and 1.90 g of fluorine. According to the Law of Definite Proportions, how much calcium should another sample of this compound contain if it contains 2.85 g of fluorine? a. 2.71 g b. 4.00 g c. 3.00 g d. 4.50 g e. 6.00 g ANS: C OBJ: Apply the Law of Definite Proportions. TOP: Chemical Formulas 12. A compound contains only magnesium and oxygen. A sample of the compound is determined to contain 3.50 g of magnesium and 2.30 g of oxygen. According to the Law of Definite Proportions, how much magnesium should another sample of this compound contain if it contains 6.91 g of oxygen? a. 1.16 g b. 10.5 g c. 4.54 g d. 55.5 g e. 0.858 g ANS: B OBJ: Apply the Law of Definite Proportions. TOP: Chemical Formulas 13. Which of the following is not the name of a cation? a. sodium b. iron (III) c. magnesium d. sulfide e. ammonium ANS: D OBJ: Understand how to name monatomic anions and cations. | Know the names and charges of polyatomic ions. TOP: Ions and Ionic Compounds
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14. Which of the following statements is incorrect? a. Potassium chloride forms molecules that consist of one K+ ion and one Cl ion. b. Ions that possess a positive charge are called cations. c. Polyatomic ions are groups of atoms that have an electric charge. d. It is acceptable to use formula unit to refer to either an ionic compound or a molecular compound. e. Ions that possess a negative charge are called anions. ANS: A OBJ: Distinguish between properties that define a substance as ionic or molecular. TOP: Ions and Ionic Compounds 15. What is the correct classification for OCl? a. polyatomic molecule b. monatomic cation c. polyatomic cation d. polyatomic anion e. monatomic anion ANS: D OBJ: Classify a species as a monatomic ion, polyatomic ion, or molecule. TOP: Ions and Ionic Compounds 16. What is the correct formula for the carbonate ion? a. CH3COO b. Cl c. CO22 d. CO32 e. (COO)2 ANS: D OBJ: Know the names, chemical formulae, and charges of common polyatomic ions. TOP: Ions and Ionic Compounds 17. Each response below lists an ion by name and by chemical symbol or formula. Also each ion is classified as monatomic or polyatomic and as a cation or anion. Which response contains an error? a. hydroxide / OH / monatomic / anion b. carbonate / CO32 / polyatomic / anion c. ammonium / NH4+ / polyatomic / cation d. magnesium / Mg2+ / monatomic / cation e. sulfite / SO32 / polyatomic / anion ANS: A OBJ: Know the names, chemical formulae, and charges of monatomic ions and common polyatomic ions. TOP: Ions and Ionic Compounds 18. Each response below lists an ion by name and by chemical symbol or formula. Also each ion is classified as monatomic or polyatomic and as a cation or anion. Which response contains an error? a. phosphate / PO43 / polyatomic / anion b. sulfite / SO32 / polyatomic / anion c. nitrite / NO3 / polyatomic / anion d. iron(II) / Fe2+ / monatomic / cation e. bromide / Br / monatomic / anion Whitten 10e
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ANS: C OBJ: Know the names, chemical formulae, and charges of monatomic ions and common polyatomic ions. TOP: Ions and Ionic Compounds 19. What is the formula for ammonium fluoride? a. AlF b. Al2F3 c. NH3F d. NH4F2 e. NH4F ANS: E OBJ: Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 20. What is the formula for manganese(III) oxide? a. MgO b. MnO c. MnO4 d. Mg2O3 e. Mn2O3 ANS: E OBJ: Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 21. What is the formula for aluminum oxide? a. Al2O3 b. Ag2O3 c. AlO3 d. AlO e. AlO2 ANS: A OBJ: Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 22. What is the name of Fe(OH)3? a. iron hydroxide b. iron trihydroxide c. iron (III) hydroxide d. iron (II) hydroxide e. none of these ANS: C OBJ: Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 23. What is the formula for copper(II) sulfate? a. CuSO4 b. Cu2SO3 c. CuSO2 d. Cu2SO4 e. Cu(SO4)2 Whitten 10e
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ANS: A OBJ: Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 24. Choose the name / formula pair that does not correctly match. a. aluminum phosphate / AlPO4 b. calcium acetate / CaCH3COO c. ammonium sulfide / (NH4)2S d. magnesium hydroxide / Mg(OH)2 e. zinc carbonate / ZnCO3 ANS: B OBJ: Translate the chemical formula of an ionic compound into a name. | Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 25. From the following ionic compounds, choose the name / formula pair that is not correctly matched. a. sodium sulfide / Na2S b. ammonium nitrate / NH4NO3 c. zinc hydroxide / Zn(OH)2 d. sodium sulfate / Na2SO3 e. calcium oxide / CaO ANS: D OBJ: Translate the chemical formula of an ionic compound into a name. | Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 26. From the following compounds choose the name / formula pair that is incorrectly matched. a. sodium sulfite / Na2SO3 b. ammonium fluoride / NH4F c. copper(II) carbonate / CuCO3 d. ferric chloride / FeCl3 e. cuprous sulfide / Co2S ANS: E OBJ: Translate the chemical formula of an ionic compound into a name. | Translate the name of an ionic compound into a chemical formula. TOP: Names and Formulas of Some Ionic Compounds 27. Which element has a mass that is 7.30 times that of carbon-12? a. Mg b. Sr c. Ca d. Br e. Rb ANS: B OBJ: Apply the modern definition of relative atomic mass. TOP: Atomic Weights
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28. Which element has a mass approximately 4 times that of an H atom? a. Be b. He c. Li d. Ti e. K ANS: B OBJ: Apply the concept of relative atomic mass. TOP: Atomic Weights 29. The molecular formula for a compound is CX4. If 2.819 g of this compound contains 0.102 g of carbon, what is the atomic weight of X? a. 320 b. 160 c. 35.5 d. 79.9 e. 39.9 ANS: D DIF: Harder Question OBJ: Calculate the atomic weight of an unknown element based on the chemical formula and mass of each component in a sample. TOP: Atomic Weights 30. How many atoms of hydrogen are in 1.00 mole of water? a. 6.02 1023 b. 1.20 1024 c. 1.81 1024 d. 2.41 1024 e. 3.01 1023 ANS: B OBJ: Translate the name of a binary molecule into a chemical formula. | Use Avogadro's number and the molecular formula to convert moles of a substance to number of atoms. TOP: The Mole 31. Calculate the number of moles of oxygen atoms in 35.2 grams of oxygen. a. 2.20 moles b. 4.42 moles c. 0.54 moles d. 2.57 moles e. 1.13 moles ANS: A OBJ: Translate the name of a diatomic element into a chemical formula. | Use the formula weight or molecular weight of a substance to convert grams of a substance to moles. TOP: The Mole 32. How many grams are contained in 0.644 mol oxygen? a. 10.3 g b. 20.6 g c. 0.0201 g d. 0.0403 g e. 0.644 g Whitten 10e
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ANS: B OBJ: Translate the name of a diatomic element into a chemical formula. | Use the formula weight or molecular weight of a substance to convert moles of a substance to grams. TOP: The Mole 33. Calculate the mass of one bromine atom. a. 2.654 1022 g b. 6.022 1023 g c. 1.661 1024 g d. 4.812 1025 g e. 1.327 1022 g ANS: E OBJ: Use Avogadro's number and atomic weight to convert the number of atoms to grams. TOP: The Mole 34. Determine the number of sulfur atoms in 27.1 g of molecular sulfur (S8). a. 0.845 b. 5.27 1023 c. 5.09 1023 d. 2.07 1023 e. 0.106 ANS: C OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use Avogadro's number, molecular formula, and molecular weight to convert grams to number of atoms. TOP: The Mole 35. Calculate the formula weight of NaHSO4. a. 193 amu b. 104 amu c. 120 amu d. 215 amu e. 185 amu ANS: C OBJ: Determine the formula weight of a substance using atomic weights and the chemical formula. TOP: Formula Weights, Molecular Weights, and Moles 36. Determine the formula weight of Ca3(PO4)2. a. 230 amu b. 279 amu c. 215 amu d. 310 amu e. 135 amu ANS: D OBJ: Determine the formula weight of a substance using atomic weights and the chemical formula. TOP: Formula Weights, Molecular Weights, and Moles
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37. What is the mass of 2.2 109 CO2 molecules? a. 9.7 1010 g b. 1.0 1012 g c. 1.2 106 g d. 4.4 1014 g e. 1.6 1013 g ANS: E OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use Avogadro's number and molecular weight to convert molecules to grams. TOP: Formula Weights, Molecular Weights, and Moles 38. What is the mass of 0.432 moles of C8H9O4? a. 86.9 g b. 391 g c. 169 g d. 113.8 g e. 73.0 g ANS: E OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use the formula weight or molecular weight of a substance to convert moles to grams. TOP: Formula Weights, Molecular Weights, and Moles 39. How many grams of CaCl2 equal 4.26 moles of CaCl2? a. 26.1 g b. 170 g c. 302 g d. 473 g e. 322 g ANS: D OBJ: Determine the formula weight of a substance using atomic weights and the chemical formula. | Use the formula weight or molecular weight of a substance to convert moles to grams. TOP: Formula Weights, Molecular Weights, and Moles 40. How many moles of POCl3 are there in 10.0 grams of POCl3? a. 6.51 102 mol b. 3.68 101 mol c. 4.09 102 mol d. 1.21 101 mol e. 1.17 103 mol ANS: A OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use the formula weight or molecular weight of a substance to convert grams to moles. TOP: Formula Weights, Molecular Weights, and Moles 41. How many moles of CCl4 are present in 118. g of carbon tetrachloride? a. 0.839 b. 1.19 c. 0.538 d. 1.30 e. 0.767 Whitten 10e
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ANS: E OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use the formula weight or molecular weight of a substance to convert grams to moles. TOP: Formula Weights, Molecular Weights, and Moles 42. How many molecules are contained in 5.00 grams of NH3? a. 5.42 1022 b. 3.00 1024 c. 3.40 1022 d. 1.77 1023 e. 9.45 1022 ANS: D OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use Avogadro's number and molecular weight or formula weight to convert grams to molecules. TOP: Formula Weights, Molecular Weights, and Moles 43. A 12.0-gram sample of Cr2(SO4)3 contains how many sulfur atoms? a. 1.84 1022 b. 1.53 1021 c. 4.82 1021 d. 6.67 1022 e. 5.52 1022 ANS: E OBJ: Determine the formula weight of a substance using atomic weights and the chemical formula. | Use Avogadro's number, molecular formula, and formula weight to convert grams to atoms. TOP: Formula Weights, Molecular Weights, and Moles 44. How many atoms of carbon are present in 34.5 g of caffeine, C8H10N4O2? a. 8.57 1023 b. 2.68 1025 c. 1.08 1024 d. 2.09 1023 e. 4.83 1023 ANS: A OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use Avogadro's number, molecular formula, and molecular weight to convert grams to atoms. TOP: Formula Weights, Molecular Weights, and Moles 45. What is the mass in grams of 5.00 1012 water molecules? a. 1.50 1010 g b. 1.67 1035 g c. 2.17 1012 g d. 6.69 109 g e. 4.61 1013 g ANS: A OBJ: Translate the name of a binary molecule into a formula. | Determine the molecular weight of a substance using atomic weights and the chemical formula. | Use Avogadro's number and molecular weight to convert molecules to grams. TOP: Formula Weights, Molecular Weights, and Moles Whitten 10e
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46. Which of the following is not a correct description of 16.0 grams of methane, CH4? a. It is one mole of methane. b. It is the amount of methane that contains 12.0 g of carbon. c. It is 16.0 6.02 1023 molecules of methane. d. It is the amount of methane that contains 4.0 grams of hydrogen. e. It is the amount of methane that contains 4 6.02 1023 hydrogen atoms. ANS: C OBJ: Determine the molecular weight of a substance using atomic weights and the chemical formula.| Convert grams of a substance to moles, grams of a component, molecules, or atoms. TOP: Formula Weights, Molecular Weights, and Moles 47. A sample of ethane, C2H6, contains a total of 16N atoms, where N = 6.02 1023. How much C2H6 is in the sample? a. 2.0 g b. 30 g c. 60 g d. 16 mol e. 4 mol ANS: C DIF: Harder Question OBJ: Determine the molecular weight of a substance using atomic weights and the formula of the substance.| Use Avogadro's number, molecular formula, and molecular weight to convert total atoms in a sample to grams or moles. TOP: Formula Weights, Molecular Weights, and Moles 48. Suppose you have a 100-gram sample of each of the following compounds. Which sample contains the smallest number of moles of compound? a. NH3 b. MgCl2 c. H3PO4 d. CrCl3 e. NaCl ANS: D OBJ: Understand and apply the relationship between mass, molar mass, and moles of a sample. TOP: Formula Weights, Molecular Weights, and Moles 49. A mole of a compound composed of nitrogen and oxygen (NxOy) has a molecular weight of 92.0 g/mol. What is its formula? a. NO b. N2O4 c. NO3 d. N2O e. NO2 ANS: B OBJ: Translate molecular weight into a molecular formula. TOP: Formula Weights, Molecular Weights, and Moles
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50. What is the percent by mass of sulfur in Al2(SO4)3? a. 9.38% b. 18.8% c. 24.6% d. 28.1% e. 35.4% ANS: D OBJ: Calculate percent mass of a component given the chemical formula of the substance. TOP: Percent Composition and Formulas of Compounds 51. Calculate the percent by mass of nitrogen in ammonium carbonate, NH4NO3. a. 17.5% b. 27.8% c. 29.2% d. 35.0% e. 2.86% ANS: D OBJ: Calculate percent mass of a component given the chemical formula of the substance. TOP: Percent Composition and Formulas of Compounds 52. Calculate the percent composition of K2CO3. a. % K = 58.2% % C = 17.9% % O = 23.9% b. % K = 28.2% % C = 8.8% % O = 35.9% c. % K = 56.6% % C = 8.7% % O = 34.7% d. % K = 39.4% % C = 12.0% % O = 48.4% e. % K = 35.1% % C = 21.6% % O = 43.2% ANS: C OBJ: Calculate percent mass of a component given the chemical formula of the substance. TOP: Percent Composition and Formulas of Compounds 53. What is the percentage of carbon in potassium hydrogen phthalate, KC6H4(COO)(COOH)? a. 35.2% b. 58.2% c. 47.1% d. 70.6% e. 19.2% ANS: C OBJ: Calculate percent mass of a component given the chemical formula of the substance. TOP: Percent Composition and Formulas of Compounds 54. Analysis of a sample of a covalent compound showed that it contained 14.4% hydrogen and 85.6% carbon by mass. What is the empirical formula for this compound? a. CH b. CH2 c. CH3 d. C2H4 e. C2H5 ANS: B OBJ: Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition Whitten 10e
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55. What is the empirical formula for a compound containing 68.3% lead, 10.6% sulfur and the remainder oxygen? a. PbSO2 b. PbSO3 c. PbS2O3 d. PbSO4 e. Pb2SO4 ANS: D OBJ: Calculate the percent mass of a third component from the data provided. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 56. A compound contains sulfur, oxygen, and chlorine. Analysis shows that it contains by mass 26.95% sulfur and 59.61% chlorine. What is the simplest formula for this compound? a. SOCl b. SOCl2 c. SO2Cl2 d. SO2Cl e. S2OCl2 ANS: B OBJ: Calculate the percent mass of a third component from the data provided. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 57. A compound contains carbon, oxygen, and hydrogen. Analysis of a sample showed that it contained by mass 68.9% carbon and 4.92% hydrogen. What is the simplest formula for this compound? a. C6H6O2 b. C7H6O2 c. C8H6O2 d. C6H4O3 e. C7H8O ANS: B OBJ: Calculate the percent mass of a third component from the data provided. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 58. A sample of a compound containing nitrogen, hydrogen, and oxygen is found to contain 22.2% nitrogen and 1.59% hydrogen. What is the simplest formula for this compound? a. HNO b. H2N2O3 c. H2NO3 d. HNO2 e. HNO3 ANS: E OBJ: Calculate the percent mass of a third component from the data provided. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition
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59. A 4.628-g sample of an oxide of iron was found to contain 3.348 g of iron and 1.280 g of oxygen. What is simplest formula for this compound? a. FeO b. Fe2O3 c. Fe3O4 d. FeO2 e. Fe3O2 ANS: C OBJ: Derive percent mass from experimental data. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 60. A 2.086-g sample of a compound contains 0.884 g of cobalt, 0.482 g of sulfur, and 0.720 g of oxygen. What is its simplest formula? a. CoSO3 b. CoSO4 c. Co(SO3)2 d. Co(SO4)2 e. Co3(SO4)4 ANS: A OBJ: Derive percent mass from experimental data. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 61. What is the simplest formula for Chalcocite if a sample of this ore contains 8.274 g copper and 2.088 g sulfur? a. CuS3 b. CuS c. CuS2 d. Cu2S3 e. Cu2S ANS: E OBJ: Derive percent mass from experimental data. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 62. Determine the simplest formula for a hydrocarbon if the complete combustion of a sample produces 5.28 g of CO2 and 1.62 g of H2O. a. C2H3 b. CH2 c. CH3 d. CH e. C2H5 ANS: A OBJ: Understand the term hydrocarbon.| Derive percent mass from experimental data. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition
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63. Determine the simplest formula for a hydrocarbon if the complete combustion of a sample produces 3.96 g of CO2 and 2.16 g of H2O. a. C2H3 b. C3H8 c. CH3 d. CH e. C2H5 ANS: B OBJ: Understand the term hydrocarbon.| Derive percent mass from experimental data. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 64. A compound is known to contain only carbon, hydrogen, and oxygen. If the complete combustion of a 0.150-g sample of this compound produces 0.225 g of CO2 and 0.0614 g of H2O, what is the empirical formula of this compound? a. C3H4 b. CH4O c. C3HO3 d. C3H4O3 e. C5H7O5 ANS: D OBJ: Calculate the mass of oxygen in the sample from the data provided. | Derive percent mass from experimental data. | Convert percent mass to the simplest formula (empirical formula). TOP: Derivation of Formulas from Elemental Composition 65. Glucose has a molecular weight of 180.2 g and an empirical formula CH2O. What is its molecular formula? a. C8H4O5 b. C6H12O6 c. C12H22O11 d. C10H12O3 e. CH2O ANS: B OBJ: Determine the molecular formula from the molecular weight and simplest formula (empirical formula). TOP: Determination of Molecular Formulas 66. A compound contains, by mass, 87.5% nitrogen and 12.5% hydrogen. Its molecular weight is found to be 32 g/mol. What is its molecular formula? a. N2H6 b. N2H4 c. N2H5 d. NH3 e. NH2 ANS: B OBJ: Convert percent mass to the simplest formula (empirical formula). | Determine the molecular formula from the molecular weight and simplest formula (empirical formula). TOP: Determination of Molecular Formulas
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67. A compound contains only carbon, hydrogen, and oxygen. Analysis of a sample showed that it contained 54.53% C and 9.15% H. Its molecular weight was determined to be approximately 88 g/mol. What is its molecular formula? a. C2H4O b. C4H8O c. C4H8 d. C4H8O2 e. C4H12O2 ANS: D OBJ: Calculate the percent mass of a third component from the data provided. | Convert percent mass to the simplest formula (empirical formula). | Determine the molecular formula from the molecular weight and simplest formula (empirical formula). TOP: Determination of Molecular Formulas 68. Butyric acid, found in rancid butter, has a molar mass of 88 g/mol. If butyric acid is 54.5% C, 9.09% H and 36.4% O, what is the molecular formula? a. C4H8O2 b. C8H12O4 c. C2H4O d. C12H6O e. CHO2 ANS: A OBJ: Convert percent mass to the simplest formula (empirical formula). | Determine the molecular formula from the molecular weight and simplest formula (empirical formula). TOP: Determination of Molecular Formulas 69. A compound contains, by mass, 26.7% carbon, 71.1% oxygen and the remainder hydrogen. A 0.23 mole sample of this compound weighs 20.7 g. What is the molecular formula of this compound? a. C3H6O2 b. C2H2O4 c. C2H4O d. CHO2 e. C3OH ANS: B OBJ: Calculate the percent mass of a third component from the data provided. | Convert percent mass to the simplest formula (empirical formula).| Calculate the molecular weight of the compound from mass and moles. | Determine the molecular formula from the molecular weight and simplest formula (empirical formula). TOP: Determination of Molecular Formulas 70. What is the maximum amount of carbon dioxide that can be produced by the combustion of 0.450g of C2H5OH? a. 0.861g b. 0.430g c. 1.62g d. 44.0g e. cannot be determined
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ANS: A OBJ: Translate the name of a binary molecule into a formula. | Determine the molecular weight of a substance using atomic weights and the formula of the substance.| Using molecular weights and molecular formulas, convert grams of organic compound to grams of carbon dioxide TOP: Determination of Molecular Formulas 71. Which of the following sets illustrates the Law of Multiple Proportions? a. Li2O, Na2O, K2O b. KCl, CaCl2, ScCl3 c. , , d. O, O2, O3 e. BrF, BrF3, BrF5 ANS: E OBJ: Identify an example of the Law of Multiple Proportions. TOP: Determination of Molecular Formulas 72. What is the ratio of the masses of oxygen that combine with 1.00 gram of lead in the compounds PbO, PbO2, and Pb2O3? a. 1:2:2 b. 1:2:1 c. 2:4:4 d. 6:12:8 e. 2:4:3 ANS: E DIF: Harder Question OBJ: Apply the Law of Multiple Proportions. TOP: Determination of Molecular Formulas 73. What mass of iron is contained in 86.6 grams of chalcopyrite, CuFeS2? a. 26.3 g b. 30.4 g c. 55.8 g d. 28.5 g e. 11.8 g ANS: A OBJ: Determine the mass of a component in a sample from the sample mass and chemical formula. TOP: Some Other Interpretations of Chemical Formulas 74. What mass of tungsten is present in 10.0 lbs of wolframite, FeWO4? a. 2.21 kg b. 2.75 kg c. 5.06 lb d. 0.716 kg e. 5.85 lb ANS: B OBJ: Convert pounds to grams. | Determine the mass of a component in a sample from the sample mass and chemical formula. TOP: Some Other Interpretations of Chemical Formulas
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75. What mass of cerussite, PbCO3, would contain 25.0 grams of lead? a. 19.4 g b. 32.2 g c. 29.3 g d. 25.4 g e. 36.9 g ANS: B OBJ: Determine the mass of a compound from the chemical formula and the mass of a component. TOP: Some Other Interpretations of Chemical Formulas 76. What mass of hematite, Fe2O3, would contain 24.0 kg of iron? a. 34.3 kg b. 68.3 kg c. 44.7 kg d. 30.5 kg e. 41.4 kg ANS: A OBJ: Convert between grams and kilograms. | Determine the mass of a compound from the chemical formula and the mass of a component. TOP: Some Other Interpretations of Chemical Formulas 77. What mass of fluoristan, SnF2, would contain the same mass of tin as 306 grams of cassiterite, SnO2? a. 295 g b. 318 g c. 278 g d. 367 g e. 335 g ANS: B DIF: Harder Question OBJ: Determine the mass of a component in a sample from the sample mass and chemical formula. | Determine the mass of a compound from the chemical formula and the mass of a component. TOP: Some Other Interpretations of Chemical Formulas 78. What mass of FeCl3 would contain the same total number of ions as 16.8 g of Al2(SO4)3? a. 7.96 g b. 9.95 g c. 10.8 g d. 13.3 g e. 8.01 g ANS: B DIF: Harder Question OBJ: Recognize the ions in an ionic chemical formula. | Determine the total number of ions in a sample from the mass and chemical formula. | Determine the mass of a sample from the total ions and chemical formula. TOP: Some Other Interpretations of Chemical Formulas
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79. Heating MgSO47H2O at 150C produces MgSO4xH2O. If heating 24.4 g of pure MgSO47H2O at 150C were to give 13.7 g of pure MgSO4xH2O, calculate the value for x. a. 5 b. 4 c. 3 d. 2 e. 1 ANS: E DIF: Harder Question OBJ: Determine the simplest formula of the partially (de)hydrated product from the experimental data. TOP: Some Other Interpretations of Chemical Formulas 80. An ore of lead is 45.0% pure lead sulfide, PbS, and 55.0% impurities in which no other lead compounds are present. What mass of lead is contained in 150.0 grams of this ore? a. 71.4 g b. 67.5 g c. 58.5 g d. 9.05 g e. 18.0 g ANS: C OBJ: Determine the mass of a component in a sample from the sample mass, chemical formula, and percent composition. TOP: Purity of Samples 81. A chemical bottle containing BaSO4 is 98.7% pure. What mass of Ba is present in 162 g of this chemical? a. 47.1 g b. 96.6 g c. 94.1 g d. 98.7 g e. 95.3 g ANS: C OBJ: Determine the mass of a component in a sample from the sample mass, chemical formula, and percent composition. TOP: Purity of Samples 82. What mass of calcium metal could be obtained from one kg of limestone that is 50.0% pure CaCO3? (No other calcium-containing compounds are present.) a. 0.05 kg b. 0.2 kg c. 0.4 kg d. 0.5 kg e. 0.1 kg ANS: B OBJ: Determine the mass of a component in a sample from the sample mass, chemical formula, and percent composition. TOP: Purity of Samples
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83. A dolomite ore contains 40.0% pure MgCO3CaCO3. No other compounds of magnesium or calcium are present in the ore. What mass of magnesium and what mass of calcium are contained in 100.0 grams of this ore? a. 18.3 g Mg / 21.7 g Ca b. 7.91 g Mg / 13.0 g Ca c. 8.70 g Mg / 31.3 g Ca d. 5.27 g Mg / 8.69 g Ca e. 34.5 g Mg / 5.30 g Ca ANS: D OBJ: Determine the mass of a component in a sample from the sample mass, chemical formula, and percent composition. TOP: Purity of Samples 84. A sample of lead ore has a density of 8.80 g/mL. It is composed of two lead compounds: lead oxide, PbO (density 9.10 g/mL) and lead selenide, PbSe (density 8.10 g/mL). What percent of the ore is lead oxide? a. 96.7 % b. 89.0 % c. 70.0 % d. 92.0 % e. 86.3 % ANS: C DIF: Harder Question OBJ: Determine percent composition from the density of each component and the density of the sample. TOP: Purity of Samples 85. A 1.4-g sample of washing soda, Na2CO3 • 10H2O, has 2.9 10
21
carbon atoms. How many
oxygen atoms are present in 1.4 g of washing soda? a. 2.9 10 22 b. 2.9 10 21 c. 4.1 10 21 d. 3.8 10 22 e. 8.8 10 21 ANS: D DIF: easy OBJ: Convert between number of atoms given the formula. TOP: Formula Weights, Molecular Weights, and Moles 86. Manganese(III) monohydrogen phosphate is an ionic compound formed from Mn3+ and
HPO42-. What is the correct way to represent the formula? a. b. c. d. e.
MnHPO4+ Mn(HPO4)2Mn3+HPO42Mn2(HPO4)3 Mn6(HPO4)9
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ANS: D DIF: easy OBJ: Write an ionic formula, given the name of the compound. TOP: Names and Formulas of Some Ionic Compounds 87. How many oxygen atoms are there in a formula unit of UO2(C2H3O2)2 • NH4C2H3O2 • 5H2O? a. 4 b. 13 c. 23 d. 9 e. 11 ANS: B DIF: easy OBJ: Determine the number of oxygen atoms in a formula unit. TOP: Chemical Formulas 88. The correct name for Fe2+ is a. b. c. d. e.
monoiron ion. iron(II) ion. iron ion. iron(I) ion. iron.
ANS: B DIF: easy OBJ: Name the monatomic ions. TOP: Ions and Ionic Compounds 89. The formula of magnesium sulfide is a. MgS. b. MgSO2. c. MgSO4. d. MgSO3. e. Mg(SO4)2. ANS: A DIF: easy OBJ: Write the formula of an ionic compound given its name. TOP: Names and Formulas of Some Ionic Compounds 90. What is the subscript of potassium in the formula for potassium sulfate? a. 2 b. 5 c. 3 d. 4 e. 1 ANS: A DIF: easy OBJ: Write the formula of an ionic compound given its name. TOP: Names and Formulas of Some Ionic Compounds Whitten 10e
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91. The fully hydrated form of sodium sulfate is the decahydrate, Na2SO410H2O. When heated
the hydrated salt loses water. How many water molecules are found per formula unit in a partially dehydrated sample of sodium sulfate with a formula mass of 214.1 amu (i.e. find n for Na2SO4nH2O)? a. b. c. d. e.
4 waters. 9 waters. 1 waters. 6 waters. 5 waters.
ANS: A DIF: moderate OBJ: Calculate the moles of water per formula unit from dehydration data. TOP: Some Other Interpretations of Chemical Formulas 92. What is the molecular mass of cyclooctane, C8H16? a. 13.02 amu b. 1553.53 amu c. 97.10 amu d. 112.21 amu e. 28.14 amu ANS: D DIF: easy OBJ: Calculate the formula mass given the formula. TOP: Formula Weights, Molecular Weights, and Moles 93. A 1.488 g sample of an element contains 8.708 1021 atoms. What is the element symbol? a. b. c. d. e.
Rh Sn Cd Ag Te
ANS: A DIF: moderate OBJ: Convert a mass and number of atoms to a formula weight. TOP: Formula Weights, Molecular Weights, and Moles 94. What is the empirical formula of an oxide of nitrogen that contains 36.84 % nitrogen by mass? a. NO b. N2O5 c. NO2 d. N2O e. N2O3 ANS: E DIF: moderate OBJ: Determine the empirical formula from the percentage composition. TOP: Percent Composition and Formulas of Compounds Whitten 10e
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95. Which of the following samples contains the greatest number of atoms? a. 7.25g Li b. 73.21g Zn c. 90.00g Br d. 140.87g Sb e. 152.11g Cs ANS: D OBJ: Identify the sample with the greatest number of atoms. TOP: Formula Weights, Molecular Weights, and Moles 96. How many atoms of chlorine are present in 2.42 grams of boron trichloride, BCl3? a. 1.24 x 1022 atoms b. 3.73 x 1022 atoms c. 4.15 x 1021 atoms d. 5.69 x 1025 atoms e. 5.14 x 1026 atoms ANS: B OBJ: Determine the number of atoms of one atom type in a compound. TOP: Formula Weights, Molecular Weights, and Moles 97. How many moles of calcium are there in a sample of calcium that contains 1.48 x 1024
atoms? a. 0.407 mol
b. 2.46 mol
c. 3.57 mol
d. 16.3 mol
e. 98.5 mol
ANS: B OBJ: Determine the number of moles given number of atoms. TOP: Formula Weights, Molecular Weights, and Moles 98. How many ammonia (NH3) molecules are there in a 115 g sample of ammonia? a. 3.07 x 1020 b. 5.24 x 1021 c. 1.91 x 1022 d. 4.06 x 1024 e. 1.18 x 1027 ANS: D OBJ: Determine the number of molecules in a sample. TOP: Formula Weights, Molecular Weights, and Moles 99. What are the empirical and molecular formulas for the following compound?
(C = dark atoms, H = light atoms) a. C6H6 (molecular) CH (empirical) b. C6H12 (molecular) CH2 (empirical)
c. CH (molecular) C6H6 (empirical) d. CH2 (molecular) C6H12 (empirical)
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ANS: B OBJ: Determine the empirical and molecular formula given the ball and stick model. TOP: Chemical Formulas 100. When the element magnesium reacts, it forms the ion: a. Mg2+ b. Mg+ c. Mn2+ d. Mn+ e. Cannot tell – it has a variable charge ANS: A OBJ: Determine the charge of a group 2A metal in its compounds. TOP: Names and Formulas of Some Ionic Compounds 101. What is the correct systematic name for Na2SO3? a. Sodium sulfate b. Sodium sulfite c. Sodium(III) sulfate d. Disodium trisulfide e. Disodium monosulfate ANS: B OBJ: Name the ionic compound of a polyatomic ion. TOP: Names and Formulas of Some Ionic Compounds 102. What is the formula for the compound which forms between the ammonium ion and bromide
ion? a. NH3Br b. NH4Br c. NH3Br2 d. NH4Br2 e. (NH4)2Br ANS: B OBJ: Name the ionic compound of a polyatomic ion. TOP: Names and Formulas of Some Ionic Compounds 103. Which of the following pairs is incorrect? a. CaCl2, calcium chloride b. Fe(OH)3, iron(III) hydroxide c. KMnO4, potassium permanganate d. LiCr2O7, lithium dichromate e. CCl4, carbon tetrachloride ANS: D OBJ: Identify the incorrect ionic compound formula and name. TOP: Names and Formulas of Some Ionic Compounds
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104. What is the chemical formula for nitric acid? a. HNO2 b. HNO3 c. HNO4
d. H2NO3
e. H2NO2
ANS: B OBJ: Identify the formula given the acid name. TOP: Names and Formulas of Some Molecular Compounds CONCEPTUAL 1. Discuss the accuracy of this statement: All matter in the universe in made of only three particles. OBJ: Define matter. TOP: Structure of the Atom 2. Why isn't it correct to refer to a molecule of aluminum chloride? OBJ: Distinguish between properties that define a substance as ionic or molecular. TOP: Chemical Formulas | Ions and Ionic Compounds 3. Would atomic weights of elements be different if another standard was chosen to represent the atomic mass unit (amu)? Would their relative masses change? OBJ: Define atomic mass unit.| Define relative atomic mass.| Discuss the effect using a standard other than C-12 to define atomic mass units. 4. Explain how it is possible for many different compounds to have the same empirical formula. OBJ: Compare and contrast the terms simplest formula (empirical formula) and molecular formula. TOP: Chemical Formulas 5. Why is the purity of a chemical listed on the label? Are there any situations where purity is not very important? OBJ: Discuss the importance of purity in chemistry and chemistry related applications. TOP: Purity of Samples 6. You are in charge of making a backup oxygen generator for the space shuttle. The chemical compounds that will decompose to give oxygen in your system are LiClO3 or KClO3. Which compound would you choose and why? OBJ: Understand and apply the relationship between mass, molar mass, and moles of a sample.| Compare the quantities of dioxygen produced from identical amounts of chlorate salts. TOP: Formula Weights, Molecular Weights, and Moles
Chapter 3—Chemical Equations and Reaction Stoichiometry MULTIPLE CHOICE 1. Which of the following is not a consequence of the Law of Conservation of Matter? a. It provides a basis for balancing chemical equations. b. It means that there will be no observable change in the quantity of matter during a chemical reaction. c. As a result, there will be the same number of moles on both the reactant and the product Whitten 10e
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side of a balanced equation. d. It can be stated as "matter is neither created nor destroyed during a chemical reaction." e. All of these are a consequence of the Law of Conservation of Mass. ANS: C OBJ: Understand the implications of the Law of Conservation of Matter. TOP: Chemical Equations 2. Balancing a chemical equation so that it obeys the law of conservation of matter requires: a. Adjusting the coefficients in front of the formulas so there are the same number and type of atom on both sides of the equation. b. Making sure the reactants and products are in the same phase. c. Keeping the total charge the same on both sides of the equation. d. Changing the formulas of the products and reactants. e. Keeping the same number of molecules on both sides of the equation. ANS: A OBJ: Understand the implications of the Law of Conservation of Matter. TOP: Chemical Equations 3. What scientific law requires that subscripts in formulas should never be changed while balancing a chemical equation? a. Law of Multiple Proportions b. Law of Definite Proportions c. Law of Conservation of Matter d. Law of Conservation of Matter and Energy e. Law of Conservation of Energy ANS: B OBJ: Understand the implications of the Law of Definite Proportions. TOP: Chemical Equations 4. Balance the following equation with the smallest whole number coefficients. What is the coefficient for O2 in the balanced equation? C4H10 + O2 CO2 + H2O a. b. c. d. e.
9 5 15 6 13
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ANS: E OBJ: Balance a chemical equation. TOP: Chemical Equations 5. Balance the following equation with the smallest whole number coefficients. What is the coefficient for O2 in the balanced equation? C4H9SO + O2 CO2 + SO2 + H2O a. b. c. d. e.
54 29 23 32 27
ANS: E DIF: Harder Question OBJ: Balance a chemical equation. TOP: Chemical Equations 6. What is the coefficient for carbon dioxide when the following equation showing the combustion of isopropyl alcohol is balanced with the smallest whole number coefficients? C3H8O + O2 CO2 + H2O a. b. c. d. e.
3 6 13 4 1
ANS: B OBJ: Balance a chemical equation. TOP: Chemical Equations 7. Balance the following equation with the smallest whole number coefficients. What is the coefficient for H2O in the balanced equation? Al(OH)3 + HCl AlCl3 + H2O a. b. c. d. e.
1 2 3 14 5
ANS: C OBJ: Balance a chemical equation. TOP: Chemical Equations
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8. Balance the following equation with the smallest whole number coefficients. What is the coefficient for H2O in the balanced equation? LiBF4 + H2O H3BO3 + HF + LiF a. b. c. d. e.
3 2 5 6 8
ANS: A OBJ: Balance a chemical equation. TOP: Chemical Equations 9. What is the coefficient for HBr when the following equation is balanced with the smallest whole number coefficients? Br2 + H2O HBr + HBrO3 a. b. c. d. e.
5 7 8 3 6
ANS: A OBJ: Balance a chemical equation. TOP: Chemical Equations 10. Balance the following equation with the smallest whole number coefficients. What is the coefficient for NH3 in the balanced equation? Fe(NO3)3 + NH3 + H2O Fe(OH)3 + NH4NO3 a. b. c. d. e.
1 3 2 6 4
ANS: B OBJ: Balance a chemical equation. TOP: Chemical Equations 11. Elemental phosphorus is produced from calcium phosphate in the following reaction. What is the coefficient for C when this equation is balanced with the smallest whole number coefficients? Ca3(PO4)2 + SiO2 + C P4 + CO + CaSiO3 a. b. c. d. e.
10 3 1 6 4
ANS: A OBJ: Balance a chemical equation. TOP: Chemical Equations Whitten 10e
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12. When heated lead nitrate decomposes according to the following equation. What is the coefficient for NO2 when the this equation is balanced with the smallest whole number coefficients? Pb(NO3)2 PbO + O2 + NO2 a. b. c. d. e.
1 2 3 4 5
ANS: D OBJ: Balance a chemical equation. TOP: Chemical Equations 13. The reaction of a hydrocarbon with oxygen to produce CO2 and water is called complete combustion. Write the balanced reaction for the complete combustion of heptane, C7H16, with the smallest whole number coefficients. Then choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". a. 23 b. 27 c. 29 d. 30 e. 32 ANS: B DIF: Harder Question OBJ: Write a chemical equation for the combustion of a hydrocarbon in oxygen, producing water and carbon dioxide. | Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 14. The discharge reaction that occurs in a nickel-cadmium (nicad) battery is shown below. Choose the answer that represents the sum of all the coefficients when this equation is balanced using the smallest whole number coefficients. Cd + NiO2 + H2O Cd(OH)2 + Ni(OH)2 a. b. c. d. e.
5 6 7 10 5
ANS: B OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations
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15. One of the reactions that take place inside a blast furnace to produce iron is the reduction of iron ore by carbon monoxide. Choose the answer that represents the sum of all the coefficients when this equation is balanced using the smallest whole number coefficients. Fe2O3 + CO CO2 + Fe a. b. c. d. e.
5 9 4 7 6
ANS: B OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 16. Ultra-pure Si is required to produce semi-conductors. The first step in this process is combining silicon dioxide with carbon and chlorine. Choose the answer that represents the sum of all the coefficients when this equation is balanced using the smallest whole number coefficients. SiO2 + C + Cl2 CO + SiCl4 a. b. c. d. e.
5 6 16 7 8
ANS: E OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 17. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". Cr + H2SO4 Cr2(SO4)3 + H2 a. b. c. d. e.
7 9 11 13 15
ANS: B OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 18. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". P4 + Cl2 PCl5 a. b. c. d. e.
7 9 11 13 15
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ANS: E OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 19. What is the sum of all coefficients when the following equation is balanced, using the smallest whole number coefficients? Do not forget coefficients of "one". CS2 + Cl2 CCl4 + S2Cl2 a. b. c. d. e.
6 8 10 12 14
ANS: A OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 20. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". RbOH + H3PO4 Rb3PO4 + H2O a. b. c. d. e.
8 10 12 4 6
ANS: A OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 21. What is the sum of all coefficients when the following equation is balanced, using the smallest whole number coefficients? Do not forget coefficients of "one". Cl2O7 + Ca(OH)2 Ca(ClO4)2 + H2O a. b. c. d. e.
6 8 10 4 5
ANS: D OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations
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22. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". XeF2 + H2O Xe + HF + O2 a. b. c. d. e.
10 11 13 15 16
ANS: B OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 23. What is the sum of all coefficients when the following equation is balanced, using the smallest whole number coefficients? Do not forget coefficients of "one". SiCl4 + H2O H4SiO4 + HCl a. b. c. d. e.
6 8 10 12 14
ANS: C OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 24. What is the sum of all coefficients when the following equation is balanced, using the smallest whole number coefficients? Do not forget coefficients of "one". Ag + H2S + O2 Ag2S + H2O a. b. c. d. e.
9 10 11 12 14
ANS: C OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 25. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". ZrO2 + CCl4 ZrCl4 + COCl2 a. b. c. d. e.
6 8 10 12 14
ANS: A OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations Whitten 10e
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26. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". Na2O + P4O10 Na3PO4 a. b. c. d. e.
5 8 9 10 11
ANS: E OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 27. What is the sum of all coefficients when the following equation is balanced, using the smallest whole number coefficients? Do not forget coefficients of "one". PtCl4 + XeF2 PtF6 + ClF + Xe a. b. c. d. e.
16 22 24 26 32
ANS: A OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 28. Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. Do not forget coefficients of "one". CuSO4 + NH3 + H2O (NH4)2SO4 + Cu(NH3)4(OH)2 a. b. c. d. e.
8 9 11 12 14
ANS: C OBJ: Balance a chemical equation. | Sum the coefficients. TOP: Chemical Equations 29. Consider the following balanced equation. 2H2 + O2 2H2O Which one of the following statements is false? a. One molecule of O2 will react with 2 molecules of H2. b. One mole of O2 will react with 2 moles of H2. c. The complete reaction of 32.0 g of O2 will produce 2 moles of H2O. d. The complete reaction of 2.0 g of H2 will produce 36.0 g of H2O. e. The amount of reaction that consumes 32.0 g of O2 produces 36.0 g of H2O. ANS: D OBJ: Translate a balanced chemical equation into words. TOP: Calculations Based on Chemical Equations Whitten 10e
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30. How many molecules of O2 would react with 56 C2H6 molecules according to the following balanced equation? 2C2H6 + 7O2 4CO2 + 6H2O a. b. c. d. e.
196 392 112 50 784
ANS: A OBJ: Use the balanced chemical reaction to convert molecules organic reactant to molecules dioxygen. TOP: Calculations Based on Chemical Equations 31. How many moles of O2 are required to react with 23.5 moles of methanol? 2CH3OH + 3O2 2CO2 + 4H2O a. b. c. d. e.
47.0 35.3 11.8 40 23.5
ANS: B OBJ: Use the balanced chemical reaction to convert moles organic reactant to moles dioxygen. TOP: Calculations Based on Chemical Equations 32. Ammonium nitrate fertilizer is sometimes used as an explosive. How many moles of water can be formed from the decomposition of 13.2 moles of ammonium nitrate? 2NH4NO3 2N2 + O2 + 4H2 a. 6.60 b. 14.0 c. 26.4 d. 13.2 e. 18.0 ANS: C OBJ: Use the balanced chemical reaction to convert moles reactant to moles product. TOP: Calculations Based on Chemical Equations 33. How many moles of O2 are required to burn completely 63.5 g of C6H6, according to the following equation? 2C6H6 + 15O2 12CO2 + 6H2O a. b. c. d. e.
0.814 12.2 6.1 0.109 9.21
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ANS: C OBJ: Use molecular weights and the balanced chemical reaction to convert grams organic reactant to moles dioxygen. TOP: Calculations Based on Chemical Equations 34. Propane (C3H8) burns in oxygen to form CO2 and H2O according to the following equation. How many grams of O2 are required to burn 3.01 1023 propane molecules? C3H8 + 5O2 3CO2 + 4H2O a. b. c. d. e.
80.0 g 40.0 g 160 g 16.0 g 64.0 g
ANS: A OBJ: Use Avogadro's number, molecular weights, and the balanced chemical reaction to convert molecules organic reactant to grams dioxygen. TOP: Calculations Based on Chemical Equations 35. How many moles of H2O will be produced from the complete combustion of 2.4 grams of CH4? CH4 + 2O2 CO2 + 2H2O a. b. c. d. e.
0.15 0.30 1.5 3.0 6.0
ANS: B OBJ: Use molecular weights and the balanced chemical reaction to convert grams organic reactant to moles product. TOP: Calculations Based on Chemical Equations 36. How many moles of CaCO3 would have to be decomposed to produce 129 grams of CaO? CaCO3 CaO + CO2 a. b. c. d. e.
1.75 1.86 2.00 2.25 2.30
ANS: E OBJ: Use formula weights and the balanced chemical reaction to convert grams product to moles reactant. TOP: Calculations Based on Chemical Equations
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37. Acrylonitrile, C3H3N, is a molecule used to produce a plastic called Orlon. How many grams of acrylonitrile could be produced by reacting 583 g of propene, C3H6 with excess ammonia, NH3 and oxygen? 2C3H6 + 2NH3 + 3O2 2C3H3N + 6H2O a. b. c. d. e.
368 g 1470 g 462 g 735 g 583 g
ANS: D OBJ: Use molecular weights and the balanced chemical reaction to convert grams organic reactant to grams product. TOP: Calculations Based on Chemical Equations 38. A secondary step in the process to produce ultra-pure silicon is to combine silicon tetrachloride with magnesium. How many grams of Si could be produced by reacting 2.00 kg of SiCl4 with excess Mg? SiCl4 + 2Mg Si + 2MgCl2 a. b. c. d. e.
454.1 g 33.07 g 377.5 g 12,100 g 331 g
ANS: E OBJ: Convert kilograms to grams. | Use molecular weights, atomic weights, and the balanced chemical reaction to convert grams reactant to grams product. TOP: Calculations Based on Chemical Equations 39. How many grams of magnesium are required to produce 5.000 kg of Si? SiCl4 + 2Mg Si + 2MgCl2 a. b. c. d. e.
8654 g 7581 g 4327 g 9999 g 2164 g
ANS: A OBJ: Convert kilograms to grams. | Use molecular weights, atomic weights, and the balanced chemical reaction to convert grams product to grams reactant. TOP: Calculations Based on Chemical Equations 40. How many grams of oxygen are required to burn 0.10 mole of C3H8? C3H8 + 5O2 3CO2 + 4H2O a. b. c. d. e.
8.0 g 12 g 16 g 32 g 64 g
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ANS: C OBJ: Use molecular weights and the balanced chemical reaction to convert moles organic reactant to grams dioxygen. TOP: Calculations Based on Chemical Equations 41. If sufficient acid is used to react completely with 72.9 g of magnesium, how much hydrogen will be produced? 2HCl + Mg MgCl2 + H2 a. b. c. d. e.
4.5 g 3.0 mol 1.5 mol 9.0 g 6.0 mol
ANS: B OBJ: Use molecular weights, atomic weights, and the balanced chemical reaction to convert grams reactant to grams or moles product. TOP: Calculations Based on Chemical Equations 42. How many grams of O2 are required to burn 46.0 grams of C5H12? C5H12 + 8O2 5CO2 + 6H2O a. b. c. d. e.
1.78 g 828 g 164 g 104 g 12.9 g
ANS: C OBJ: Use molecular weights and the balanced chemical reaction to convert grams organic reactant to grams dioxygen. TOP: Calculations Based on Chemical Equations 43. What mass of phosphoric acid, H3PO4, would actually react with 7.17 grams of LiOH? 3LiOH + H3PO4 Li3PO4 + 3H2O a. b. c. d. e.
3.27 g 6.53 g 9.80 g 19.6 g 29.4 g
ANS: C OBJ: Use formula weights, molecular weights, and the balanced chemical reaction to convert grams of one reactant to grams of another. TOP: Calculations Based on Chemical Equations
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44. The single largest use of phosphoric acid is in the production of fertilizer. How many grams of phosphoric acid (with excess NH3) are required to produce 800 g of (NH4)2HPO4, a common fertilizer? H3PO4 + 2NH3 (NH4)2HPO4 a. b. c. d. e.
1186 g 593 g 391 g 686 g 1080 g
ANS: B OBJ: Use molecular weights, formula weights, and the balanced chemical reaction to convert grams product to grams reactant. TOP: Calculations Based on Chemical Equations 45. What mass of SiF4 could be produced by the reaction of 15 g of SiO2 with an excess of HF? The equation for the reaction is: SiO2 + 4HF SiF4 + 2H2O a. b. c. d. e.
1.04 g 12 g 26 g 104 g 52 g
ANS: C OBJ: Use molecular weights, formula weights, and the balanced chemical reaction to convert grams reactant to grams product. TOP: Calculations Based on Chemical Equations 46. What mass of SrF2 can be prepared from the reaction of 10.0 g of Sr(OH)2 with excess HF? Sr(OH)2 + 2HF SrF2 + 2H2O a. b. c. d. e.
9.67 g 9.82 g 10.0 g 11.6 g 10.3 g
ANS: E OBJ: Use formula weights and the balanced chemical reaction to convert grams reactant to grams product. TOP: Calculations Based on Chemical Equations 47. What mass of Li3PO4 can be prepared from the complete reaction of 7.17 grams of LiOH with a stoichiometric amount of H3PO4? 3LiOH + H3PO4 Li3PO4 + 3H2O a. b. c. d. e.
9.80 g 9.34 g 9.61 g 10.4 g 11.6 g
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ANS: E OBJ: Use formula weights and the balanced chemical reaction to convert grams reactant to grams product. TOP: Calculations Based on Chemical Equations 48. What is the total mass of products formed when 3.2 grams of CH4 is burned in air? CH4 + 2O2 CO2 + 2H2O a. b. c. d. e.
16 g 36 g 44 g 80 g 32 g
ANS: A DIF: Harder Question OBJ: Use molecular weights and the balanced chemical reaction to convert grams organic reactant to grams product.| Sum the mass of all products. TOP: Calculations Based on Chemical Equations 49. How many grams of KOH would have to be reacted with excess CO2 to produce 69.1 grams of K2CO3? 2KOH + CO2 K2CO3 + H2O a. b. c. d. e.
56.1 g 112 g 28.1 g 222 g 84.2 g
ANS: A OBJ: Use formula weights and the balanced chemical reaction to convert grams product to grams reactant. TOP: Calculations Based on Chemical Equations 50. A mixture of calcium oxide, CaO, and calcium carbonate, CaCO3, that had a mass of 3.454 g was heated until all the calcium carbonate was decomposed according to the following equation. After heating, the sample had a mass of 3.102 g. Calculate the mass of CaCO3 present in the original sample. CaCO3 (solid) CaO (solid) + CO2 (gas) a. b. c. d. e.
0.400 g 0.800 g 1.00 g 1.60 g 0.200 g
ANS: B DIF: Harder Question OBJ: Determine the grams of carbon dioxide released. | Use formula weights, molecular weights, and the balanced chemical reaction to convert grams carbon dioxide to grams reactant. TOP: Calculations Based on Chemical Equations
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51. The following statements apply to the interpretation of chemical equations. Not all of the statements are true. Which statement is false? a. The number of grams of the reactants must equal the number of grams of products in a balanced equation. b. There will always be some of the excess reagent left at the completion of the reaction. c. The following equation for the reaction involving hypothetical substances, A, B, C, and D, implies that the products C and D are always produced in a three to one mole ratio. A + 2B 3C + D d. The equation shown in c implies that in any reaction involving A and B as reactants, A must be the limiting reactant. e. The total number of atoms in the reactants that react must always equal the total number of atoms in the products produced by the reaction. ANS: D OBJ: Understand the implications of a balanced chemical equation. | Understand the term limiting reactant. | Understand the term excess reagent. TOP: The Limiting Reactant Concept 52. If 25.0 g of each reactant were used in performing the following reaction, which would be the limiting reactant? 3PbO2 + Cr2(SO4)3 + K2SO4 + H2O 3PbSO4 + K2Cr2O7 + H2SO4 a. b. c. d. e.
PbO2 H2O K2SO4 PbSO4 Cr2(SO4)3
ANS: A OBJ: Use molecular weights, formula weights, and the balanced chemical equation to determine the limiting reactant. TOP: The Limiting Reactant Concept 53. If 20.0 g of each reactant were used in performing the following reaction, which would be the limiting reactant? 2MnO2 + 4KOH + O2 + Cl2 2KMnO4 + 2KCl + 2H2O a. b. c. d. e.
MnO2 KOH O2 Cl2 KMnO4
ANS: B OBJ: Use molecular weights, formula weights, and the balanced chemical equation to determine the limiting reactant. TOP: The Limiting Reactant Concept
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54. How many moles of carbon dioxide could be produced if 10 moles of octane, C8H18, are combined with 20 moles of oxygen? C8H18 + 25O2 16CO2 + 18H2O a. b. c. d. e.
40 mol 8.0 mol 12.8 mol 62.5 mol 20 mol
ANS: C OBJ: Use the balanced chemical equation to determine the limiting reactant. TOP: The Limiting Reactant Concept 55. If 58 moles of NH3 are combined with 32 moles of sulfuric acid, what is the limiting reactant and how much of the excess reactant is left over? 2NH3 + H2SO4 (NH4)2SO4 a. b. c. d. e.
H2SO4; 29 mol NH3; 1.0 mol NH3; 29 mol NH3; 3.0 mol H2SO4; 3.0 mol
ANS: D OBJ: Use the balanced chemical equation to determine the limiting reactant and the remaining moles of excess reactant. TOP: The Limiting Reactant Concept 56. If 25 grams of methane, CH4, and 30 g of ammonia, NH3, are combined w/excess oxygen, how much methane or ammonia will be left when the reaction is finished? CH4 + NH3 + O2 2HCN + 6H2O a. b. c. d. e.
0.10g NH3 0.10 mol CH4 0.10 g CH4 10 g NH3 0.10 mol NH3
ANS: E OBJ: Use molecular weights and the balanced chemical equation to determine the limiting reactant and the remaining moles of limited reactant in excess. TOP: The Limiting Reactant Concept 57. The thermite reaction is performed using 8.6 g Fe2O3 and 1.8 g powdered Al metal. Which reactant is in excess and by how much? Fe2O3 + 2 Al Al2O3 + 2Fe a. b. c. d. e.
Al; 0.3 g Fe2O3; 2.0 g Al; 2.1 g Al; 1.1 g Fe2O3; 3.3 g
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ANS: E OBJ: Use formula weights, atomic weights, and the balanced chemical equation to determine the limiting reactant and the grams remaining of the reactant in excess. TOP: The Limiting Reactant Concept 58. What mass of Cu(NO3)2 can be prepared from the reaction of 3.65 grams of copper with 5.16 grams of HNO3? Cu + 2HNO3 Cu(NO3)2 + H2 a. b. c. d. e.
15.4 g 10.8 g 5.14 g 10.3 g 7.68 g
ANS: E OBJ: Use molecular weights, atomic weights, and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant,the balanced chemical equation, and molecular weights, formula weights, and atomic weights as needed, to determine grams product. TOP: The Limiting Reactant Concept 59. What mass of SrF2 can be prepared from the reaction of 8.05 g of Sr(OH)2 with 3.88 g of HF? Sr(OH)2 + 2HF SrF2 + 2H2O a. b. c. d. e.
11.7 g 12.2 g 10.5 g 8.31 g 8.62 g
ANS: D OBJ: Use molecular weights, formula weights, and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, formula weights and molecular weights as needed, and the balanced chemical equation to determine grams product. TOP: The Limiting Reactant Concept 60. How many grams of nitric acid can be prepared from the reaction of 69.0 grams of nitrogen dioxide with 36.0 grams of water? 3NO2 + H2O 2HNO3 + NO a. b. c. d. e.
252 g 63.0 g 116 g 84.0 g 76.0 g
ANS: B OBJ: Use molecular weights and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, molecular weights as needed, and the balanced chemical equation to determine grams product. TOP: The Limiting Reactant Concept
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61. Salicylic acid reacts with acetic anhydride to form aspirin, acetylsalicylic acid. How much aspirin can be produced from the reaction of 100. g of salicylic acid and 100. g of acetic anhydride? 2 C7H6O3 + C4H6O3 2 C9H8O4 + H2O salicylic acid acetic aspirin anhydride a. b. c. d. e.
88.2 g 44.1 g 176 g 130 g 65.2 g
ANS: A OBJ: Use molecular weights and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, molecular weights as needed, and the balanced chemical equation to determine grams product. TOP: The Limiting Reactant Concept 62. How many grams of MnSO4 can be prepared from the reaction of 15.0 g of KMnO4 with 22.6 g of H2SO3? 2KMnO4 + 5H2SO3 2MnSO4 + K2SO4 + 2H2SO4 a. b. c. d. e.
14.3 g 15.4 g 15.9 g 16.6 g 17.4 g
ANS: A OBJ: Use molecular weights, formula weights, and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, molecular weights and formula weights as needed, and the balanced chemical equation to determine grams product. TOP: The Limiting Reactant Concept 63. A mixture of 13.1 g Zn and 22.0 g I2 is reacted to completion in a closed, evacuated container. What are the contents of the container after this reaction? Zn + I2 ZnI2 a. b. c. d. e.
27.7 g of ZnI2 and 5.7 g of Zn 63.9 g of ZnI2 and 3.4 g of I2 63.9 g of ZnI2 27.7 g of ZnI2 and 7.4 g of Zn 31.2 g of ZnI2 and 3.9 g of I2
ANS: D OBJ: Use molecular weights, formula weights, and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, molecular weights and formula weights as needed, and the balanced chemical equation to determine grams product and grams of reactant in excess. TOP: The Limiting Reactant Concept
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64. What is the percent yield of CO2 if the reaction of 10.0 grams of CO with excess O2 produces 12.8 grams of CO2? 2CO(g) + O2(g) 2CO2(g) a. b. c. d. e.
76.4% 78.1% 81.5% 84.4% 88.9%
ANS: C OBJ: Use molecular weights and the balanced chemical reaction to determine the theoretical yield. | Calculate the percent yield given the actual yield. TOP: Percent Yields from Chemical Reactions 65. Salicylic acid reacts with acetic anhydride to form aspirin, acetylsalicylic acid. If the percent yield in this reaction is 78.5%, what mass of salicylic acid is required to produce 150. g aspirin? 2 C7H6O3 + C4H6O3 2 C9H8O4 + H2O salicylic acid acetic aspirin anhydride a. b. c. d. e.
292 g 146 g 90.0 g 73.0 g 191 g
ANS: B OBJ: Determine the theoretical yield of product required to produce the desired mass of product given percent yield. | Use molecular weights and the balanced chemical reaction to convert theoretical grams product to grams reactant. TOP: Percent Yields from Chemical Reactions 66. The reaction of 5.0 g of CuSO4 with excess sodium hydroxide produced 2.6 g of Cu(OH)2. What percent yield of Cu(OH)2 was obtained? CuSO4 + 2NaOH Cu(OH)2 + Na2SO4 a. b. c. d. e.
52% 61% 32% 85% 92%
ANS: D OBJ: Use formula weights and the balanced chemical reaction to determine the theoretical yield. | Calculate the percent yield given the actual yield. TOP: Percent Yields from Chemical Reactions
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67. What is the percent yield of elemental sulfur if 7.54 grams of sulfur are obtained from the reaction of 6.16 grams of SO2 with an excess of H2S? 2H2S + SO2 2H2O + 3S a. b. c. d. e.
72.6% 40.8% 81.5% 88.4% 91.4%
ANS: C OBJ: Use molecular weights, atomic weights, and the balanced chemical reaction to determine the theoretical yield. | Calculate the percent yield given the actual yield. TOP: Percent Yields from Chemical Reactions 68. What is the percent yield if 28.50 of FeO reacts with excess CO and produces 17.841 g Fe? FeO + CO Fe + CO2 a. b. c. d. e.
62.62% 81% 80.55% 124% 77.72%
ANS: C OBJ: Use formula weights, atomic weights, and the balanced chemical reaction to determine the theoretical yield. | Calculate the percent yield given the actual yield. TOP: Percent Yields from Chemical Reactions 69. How many grams of PI3 could be produced from 250. g of I2 and excess phosphorus if the reaction gives a 98.5% yield? P4 + 6I2 4PI3 a. b. c. d. e.
246 g 254 g 266 g 270 g 286 g
ANS: C OBJ: Use molecular weights and the balanced chemical reaction to determine the theoretical yield. | Determine actual yield from percent yield and theoretical yield. TOP: Percent Yields from Chemical Reactions 70. Suppose 600. g of P4 reacts with 1300. g of S8. How many grams of P4S10 can be produced, assuming 80.0% yield based on the limiting reactant? 4P4 + 5S8 4P4S10 a. b. c. d. e.
4.62 102 g 1.44 103 g 2.16 103 g 4.92 103 g 6.50 102 g
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ANS: B OBJ: Use molecular weights and the balanced chemical reaction to determine the theoretical yield. | Determine actual yield from percent yield and theoretical yield. TOP: Percent Yields from Chemical Reactions 71. If 6.6 g of fluorine reacts with 5.6 g chlorine to produce 8.5 g of chlorine trifluoride, what is the limiting reactant and the percent yield of chlorine trifluoride? Cl2 + 3F2 2ClF3 a. b. c. d. e.
F2; 45% Cl2; 58% Cl2; 53% F2; 69% F2; 79%
ANS: E OBJ: Use molecular weights and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, molecular weights, and the balanced chemical reaction to determine the theoretical yield. | Calculate the percent yield given the actual yield. TOP: Percent Yields from Chemical Reactions 72. If a reaction of 5.0 g of hydrogen with 5.0 g of carbon monoxide produced 4.5 g of methanol, what was the percent yield? 2H2 + CO CH3OH a. b. c. d. e.
11% 79% 96% 24% 63%
ANS: B DIF: Harder Question OBJ: Use molecular weights and the balanced chemical equation to determine the limiting reactant. | Use the limiting reactant, molecular weights, and the balanced chemical reaction to determine the theoretical yield. | Calculate the percent yield given the actual yield. TOP: Percent Yields from Chemical Reactions 73. In the sequential reactions shown below, the first reaction has an 80% yield and the second reaction has a 60% yield. A+BC+D C+EF What is the yield of F? a. 60% b. 80% c. 20% d. 48% e. 70% ANS: D OBJ: Determine the overall percent yield given the percent yield of each step. TOP: Sequential Reactions
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74. Sulfuric acid is probably the most important industrial chemical because it is used in so many industrial processes to produce or purify other chemicals. It can be produced by a three step process. First, sulfur is burned in air to give sulfur dioxide. Second, the sulfur dioxide is converted to sulfur trioxide by passing the sulfur dioxide over a catalyst in the presence of oxygen at a high temperature. Third, the sulfur trioxide is reacted with water to form sulfuric acid. What mass of sulfuric acid would be formed from 1.00 103 kg of sulfur, if the three steps gave yields as listed below? 92.5% S + O2 SO2 72.6% 2SO2 + O2 2SO3 98.2% SO3 + H2O H2SO4 a. b. c. d. e.
4.03 103 kg 2.02 103 kg 3.06 103 kg 2.84 103 kg 2.22 103 kg
ANS: B DIF: Harder Question OBJ: Determine the overall percent yield given the percent yield of each step. | Use the sequence of balanced reactions, and molecular weights and atomic weights as needed, to convert grams reactant to grams final product. | Determine the actual yield of product from the overall percent yield. TOP: Sequential Reactions 75. Gold is recovered from low-grade ore by first dissolving it with KCN and then precipitating the solid gold by reacting the aqueous gold complex ion with Zn. How much gold could be recovered with 250. g of KCN? 4 Au + 8KCN + O2 + 2 H2O 4K[Au(CN)2] + 4KOH 4 Zn + 8 K[Au(CN)2] 8 Au + 4 K2[Zn(CN)4] a. b. c. d. e.
756 g 126 g 189 g 378 g 250 g
ANS: D OBJ: Use molecular weights, formula weights, and the balanced chemical reaction to determine the theoretical yield of gold given grams limiting reactant. TOP: Sequential Reactions 76. Ethyl butyrate (C6H12O2), "oil of pineapple", can be produced in the laboratory from butyric acid (C4H8O2), a foul-smelling liquid, and ethyl alcohol (C2H6O). First, butyric acid is reacted with PCl5 to produce butyryl chloride (C4H7ClO) which is then reacted with the ethyl alcohol to produce the ethyl butyrate. What mass of ethyl butyrate could be produced from 12.8 g of butyric acid if the first reaction gave a 65.8% yield of butyryl chloride and the second reaction gave a 88.4% yield of ethyl butyrate? C4H8O2 + PCl5 C4H7ClO + HCl + POCl3 C4H7ClO + C2H6O C6H12O2 + HCl
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a. b. c. d. e.
8.80 g 9.01 g 8.47 g 16.9 g 9.81 g
ANS: E DIF: Harder Question OBJ: Determine the overall percent yield given the percent yield of each step. | Use the sequence of balanced reactions, and molecular weights and atomic weights as needed, to convert grams reactant to grams final product. | Determine the actual yield of product from the overall percent yield. TOP: Sequential Reactions 77. What mass of silver nitrate, AgNO3, is required to prepare 800. g of 3.50% solution of AgNO3? a. 24.6 g b. 26.7 g c. 27.0 g d. 25.5 g e. 28.0 g ANS: E OBJ: Convert percent solute and total grams solution to grams solute. TOP: Concentrations of Solutions 78. What mass of water is contained in 200. grams of 15.0% KCl solution? a. 11.3 g b. 170. g c. 174. g d. 30.0 g e. 25.5 g ANS: B OBJ: Convert percent solute and total grams solution to grams solvent. TOP: Concentrations of Solutions 79. What mass of 25.0% Ba(NO3)2 solution contains 40.0 grams of Ba(NO3)2? a. 117 g b. 160 g c. 321 g d. 10.0 g e. 62.5 g ANS: B OBJ: Convert percent solute and grams solute to grams solution. TOP: Concentrations of Solutions 80. What mass of 30.0% Ca(NO3)2 solution contains 60.0 grams of water? a. 42.0 g b. 85.7 g c. 58.0 g d. 14.3 g e. 62.4 g
Whitten 10e
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82
ANS: B OBJ: Convert percent solute and grams solute to grams solution. TOP: Concentrations of Solutions 81. The density of a 7.50% solution of ammonium sulfate, (NH4)2SO4, is 1.04 g/mL. What mass of (NH4)2SO4 would be required to prepare 750. mL of this solution? a. 45.8 g b. 54.0 g c. 58.5 g d. 62.4 g e. 65.7 g ANS: C OBJ: Convert volume solution to grams solute given percent solute, and solution density. TOP: Concentrations of Solutions 82. What mass of NaF and water are required to produce 680. g of 15.0 wt % NaF solution? a. 170 g NaF; 510 g H2O b. 11 g NaF; 669 g H2O c. 578 g NaF; 102 g H2O d. 15 g NaF; 665 g H2O e. 102 g NaF; 578 g H2O ANS: E OBJ: Convert percent solute and total grams solution to grams solvent. | Convert percent solute and total grams solution to grams solute. TOP: Concentrations of Solutions 83. What volume of 40.0% NaNO3 solution contains 0.15 mole of NaNO3? Density = 1.32 g/mL. a. 42.0 mL b. 3.86 mL c. 9.60 mL d. 24.1 mL e. 38.2 mL ANS: D OBJ: Convert moles solute to volume solution given percent solute and solution density. TOP: Concentrations of Solutions 84. The molarity of a solution is defined as a. the number of moles of solute per kilogram of solvent. b. the number of moles of solute per liter of solution. c. the number of equivalent weights of solute per liter of solution. d. the number of moles of solute per kilogram of solution. e. the number of moles of solute per liter of solvent. ANS: B OBJ: Define molarity. TOP: Concentrations of Solutions
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85. Calculate the molarity of a solution that contains 70.0 g of H2SO4 in 280. mL of solution. a. 2.55 M b. 6.84 M c. 8.62 M d. 9.78 M e. 11.84 M ANS: A OBJ: Calculate solution molarity given grams solute and volume solution. TOP: Concentrations of Solutions 86. What is the molarity of 850. mL of a solution containing 46.2 grams of NaBr? a. 0.495 M b. 0.506 M c. 0.516 M d. 0.528 M e. 0.545 M ANS: D OBJ: Calculate solution molarity given solution volume and grams solute. TOP: Concentrations of Solutions 87. What volume of 0.365 M NaOH solution contains 53.4 g NaOH? a. 3.66 L b. 2.05 L c. 146 L d. 19.5 L e. 14.6 L ANS: A OBJ: Calculate volume of solution given grams solute and solution molarity. TOP: Concentrations of Solutions 88. Which of the following statements does not apply to an aqueous solution of sodium chloride? a. Water is the solvent b. The % by mass would be calculated as (mass sodium chloride/mass water). c. Sodium chloride is the solute. d. The solution is a homogeneous mixture. e. All of these statements apply to an aqueous sodium chloride solution. ANS: B OBJ: Understand the term aqueous. | Define percent solute by mass for a two component solution. | Understand the term solute. | Recognize a solution is a homogeneous mixture. TOP: Concentrations of Solutions 89. What is the molarity of a barium chloride solution prepared by dissolving 2.50 g of BaCl22H2O in enough water to make 400. mL of solution? a. 2.56 102 M b. 4.97 103 M c. 4.09 102 M d. 7.31 103 M e. 5.20 102 M
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ANS: A OBJ: Calculate solution molarity given grams solute and volume solution. TOP: Concentrations of Solutions 90. What mass of glucose (mw = 180 g/mol) must be dissolved in enough water to produce 1000. mL of 0.55 M glucose solution? a. 99 g b. 327 g c. 0.099 g d. 235 g e. 99.0 g ANS: A OBJ: Calculate grams solute given solution volume and solution molarity. TOP: Concentrations of Solutions 91. What mass of Na2SO4 is required to prepare 400. mL of 1.50 M Na2SO4 solution? a. 213 g b. 56.8 g c. 71.4 g d. 85.2 g e. 8.52 104 g ANS: D OBJ: Calculate grams solute given solution volume and solution molarity. TOP: Concentrations of Solutions 92. What volume of 0.250 M KOH solution contains 6.31 grams of KOH? a. 631 mL b. 28.1 mL c. 450 mL d. 2.22 mL e. 0.44 mL ANS: C OBJ: Calculate volume of solution given grams solute and solution molarity. TOP: Concentrations of Solutions 93. The specific gravity of commercial nitric acid solution is 1.42 and it is 70.0% HNO3 by mass. Calculate its molarity. a. 18.0 M b. 15.8 M c. 12.8 M d. 99.4 M e. 26.2 M ANS: B OBJ: Calculate solution molarity given the percent by mass and specific gravity. TOP: Concentrations of Solutions
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94. Concentrated hydrochloric acid is about 12.1 M. What volume of concentrated HCl is required to produce 5500 mL of 0.250 M? a. 980 mL b. 0.114 L c. 98 mL d. 0.211 L e. 1114 mL ANS: B OBJ: Calculate the volume of concentrated solution to be diluted given molarity concentrated solution, volume dilute solution, and molarity dilute solution. | Convert mL to L. TOP: Dilution of Solutions 95. A laboratory stock solution is 1.50 M NaOH. Calculate the volume of this stock solution that would be needed to prepare 300. mL of 0.200 M NaOH. a. 2.25 mL b. 10.0 mL c. 40.0 mL d. 1.00 mL e. 0.100 mL ANS: C OBJ: Calculate the volume of concentrated solution to be diluted given molarity concentrated solution, volume dilute solution, and molarity dilute solution. TOP: Dilution of Solutions 96. When a solution is diluted, what is the relationship of the number of moles of solute in the more concentrated initial volume of solution to the number of moles of solute in the less concentrated final volume of solution? a. The ratio of the numbers is directly proportional to the two volumes. b. The ratio of the numbers is inversely proportional to the two volumes. c. The number of moles of solute in the more concentrated initial volume is always greater. d. The number of moles of solute in the less concentrated final volume is always greater. e. The number of moles of solute in both solutions is the same. ANS: E OBJ: Compare moles of solute in a dilute solution to moles of solute in the volume of concentrated stock solution used to make the dilute solution. TOP: Dilution of Solutions 97. Calculate the molarity of the resulting solution if 25.0 mL of 1.50 M HCl solution is diluted to 500. mL. a. 13.3 M b. 1.67 M c. 0.0333 M d. 0.00417 M e. 0.0750 M ANS: E OBJ: Calculate the molarity of a dilution given volume and molarity of concentrated stock and the final volume of the dilute solution. TOP: Dilution of Solutions
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98. Calculate the molarity of the resulting solution if enough water is added to 50.0 mL of 4.20 M NaCl solution to make a solution with a volume of 2.80 L. a. 75.0 M b. 0.043 M c. 33.1 M d. 0.067 M e. 0.0750 M ANS: E OBJ: Calculate the molarity of a dilution given volume and molarity of concentrated stock and the final volume of the dilute solution. TOP: Dilution of Solutions 99. Calculate the resulting molarity of a solution prepared by mixing 25.0 mL of 0.160 M NaBr and 55.0 mL of 0.0320 M NaBr. a. 0.522 M b. 0.272 M c. 0.230 M d. 0.0658 M e. 0.0720 M ANS: E DIF: Harder Question OBJ: Determine the molarity of a solution made by mixing two known volumes of solution of differing solute concentration. TOP: Dilution of Solutions 100. Calculate the molarity of the resulting solution prepared by diluting 25.0 mL of 18.0% ammonium chloride, NH4Cl, (density = 1.05 g/mL) to a final volume of 80.0 mL. a. 0.292 M b. 0.059 M c. 1.10 M d. 0.0536 M e. 0.00105 M ANS: C DIF: Harder Question OBJ: Calculate the molarity of a dilution given volume, percent solute, and solution density of the concentrated stock and the final volume of the dilute solution. TOP: Dilution of Solutions 101. A sample of commercial perchloric acid is 70.0% HClO4 by mass; its density is 1.664 g/mL. How many milliliters of this concentrated HClO4 would be required to prepare 500. mL of 1.50 M HClO4 solution? a. 33.0 mL b. 45.3 mL c. 54.1 mL d. 64.7 mL e. 78.6 mL ANS: D DIF: Harder Question OBJ: Calculate the volume of a concentrated stock required for a dilution given percent solute and solution density of the concentrated stock and the final volume and molarity of the dilute solution. TOP: Dilution of Solutions Whitten 10e
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102. How many grams of KOH are contained in 400. mL of 0.250 M KOH solution? a. 12.4 g b. 5.61 g c. 89.8 g d. 35.1 g e. 8.98 g ANS: B OBJ: Calculate grams solute given solution volume and solution molarity. TOP: Using Solutions in Chemical Reactions 103. Silver nitrate, AgNO3, reacts with sodium chloride as indicated by the following equation. What mass of NaCl would be required to react with 200. mL of 0.200 M AgNO3 solution? AgNO3 + NaCl AgCl + NaNO3 a. b. c. d. e.
0.117 g 1.17 g 2.34 g 4.68 g 3.06 g
ANS: C OBJ: Use molarity, formula weights, and the balanced chemical reaction to convert the volume of one reactant to grams of another reactant. TOP: Using Solutions in Chemical Reactions 104. If 45.0 mL of 0.250 M PbCl4 solution reacts with 20.0 mL of (NH4)2SO4, what is the molarity of the (NH4)2SO4? PbCl4 + 2(NH4)2SO4 Pb(SO4)2 + 4NH4Cl a. b. c. d. e.
0.502 M 1.25 M 2.25 M 1.13 M 0.563 M
ANS: D OBJ: Use volume, molarity, and the balanced chemical reaction to determine a reactant molarity. TOP: Using Solutions in Chemical Reactions 105. What mass of calcium carbonate, CaCO3, is required to react with 100. mL of 2.00 M HCl solution? CaCO3 + 2HCl CaCl2 + CO2 + H2O a. b. c. d. e.
5.00 g 10.0 g 15.0 g 20.0 g 23.0 g
ANS: B OBJ: Use molarity, formula weights, and the balanced chemical reaction to convert the volume of one reactant to grams of another reactant. TOP: Using Solutions in Chemical Reactions
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106. What volume of 0.150 molar KOH is required to react with 1.259 grams of oxalic acid, (COOH)2? 2KOH + (COOH)2 K2(COO)2 + 2H2O a. b. c. d. e.
93 mL 27.9 mL 186 mL 147 mL 372 mL
ANS: C OBJ: Use molarity, molecular weight, and the balanced chemical reaction to convert the grams of one reactant to volume of another reactant. TOP: Using Solutions in Chemical Reactions 107. What volume of 0.130 M HCl solution will just react with 0.424 gram of Ba(OH)2? 2HCl + Ba(OH)2 BaCl2 + 2H2O a. b. c. d. e.
38.1 mL 32.6 mL 24.1 mL 18.6 mL 96.7 mL
ANS: A OBJ: Use molarity, formula weight, and the balanced chemical reaction to convert the grams of one reactant to volume of another reactant. TOP: Using Solutions in Chemical Reactions 108. How many grams of PbCl2 precipitate if 100. mL of 0.150 M LiCl solution reacts with an excess of Pb(NO3)2 solution? 2 LiCl + Pb(NO3)2 PbCl2 + 2 LiNO3 a. b. c. d. e.
2.09 g 8.34 g 13.9 g 4.17 g 92.7 g
ANS: A OBJ: Use molarity, formula weight, and the balanced chemical reaction to convert volume of reactant to grams of product. TOP: Using Solutions in Chemical Reactions 109. Some antacids use magnesium hydroxide to neutralize (react with) the excess hydrochloric acid in a hyperacidic stomach. What mass of magnesium hydroxide would a student need to consume if his "upset" stomach held 350. mL of 0.0325 M HCl? Mg(OH)2 + 2HCl MgCl2 + H2O a. b. c. d. e.
0.33 g 0.66 g 16 g 0.98 g 23 g
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ANS: A OBJ: Use molarity, molecular weight, and the balanced chemical reaction to convert the volume of one reactant to grams of another reactant. TOP: Using Solutions in Chemical Reactions 110. What volume of 0.132 M KOH solution would react completely with 25.8 mL of 0.198 M HCl according to the following equation? HCl + KOH KCl + H2O a. b. c. d. e.
86.4 mL 25.7 mL 38.7 mL 17.2 mL 3.86 mL
ANS: C OBJ: Use molarity and the balanced chemical reaction to convert the volume of one reactant to the volume of another reactant. TOP: Using Solutions in Chemical Reactions 111. What volume of 0.150 M AgNO3 solution is required to react with 80.0 mL of 0.0660 M CaCl2 solution according to the following reaction? 2AgNO3 + CaCl2 2AgCl + Ca(NO3)2 a. b. c. d. e.
70.4 mL 140 mL 26.8 mL 35.2 mL 60.2 mL
ANS: A OBJ: Use molarity and the balanced chemical reaction to convert the volume of one reactant to the volume of another reactant. TOP: Using Solutions in Chemical Reactions 112. Witherite is a mineral that contains barium carbonate. If a 1.68-g sample of witherite were to react completely with 24.6 mL of 0.2558 M HCl, what would be the percent of barium carbonate in the witherite sample? (Barium carbonate is the only compound present that reacts with the hydrochloric acid.) BaCO3 + 2HCl BaCl2 + CO2 + H2O a. b. c. d. e.
74.2% 37.0% 62.1% 23.4% 13.5%
ANS: B OBJ: Calculate percent composition of a sample given analysis data comprised of reactant solution volume and molarity, and the balanced chemical reaction. TOP: Using Solutions in Chemical Reactions
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113. How many grams of lithium nitrate, LiNO3 (68.9 g/mol), are required to prepare 567.9 mL of
a 0.901 M LiNO3 solution? a. 0.00743 g b. 35.3 g c. 0.0284 g d. 43.4 g e. 0.00915 g ANS: B DIF: moderate OBJ: Determine grams of solute from a volume and molarity. TOP: Concentrations of Solutions 114. What volume of 0.711 M Na2CO3 (106 g/mol) solution contains 62.2 g of Na2CO3? a. 0.417 L b. 9.27 103 L c. 0.825 L d. 4.69 103 L e. 1.21 L ANS: C DIF: moderate OBJ: Determine the volume of a solution given molarity and mass of solute. TOP: Concentrations of Solutions 115. A dilute solution is prepared by transferring 30.00 mL of a 0.2216 M stock solution to a 375.0
mL volumetric flask and diluting to mark. What is the molarity of this dilute solution? a. b. c. d. e.
0.01773 M 0.03546 M 0.02770 M 0.004432 M 0.1108 M
ANS: A DIF: easy OBJ: Calculate the molarity of a dilution given volume and molarity of concentrated stock and the final volume of the dilute solution. TOP: Dilution of Solutions 116. The reaction of H2SO4 with NaOH is represented by the equation
H2SO4(aq) + 2NaOH(aq) Na2SO4(aq) + 2H2O(l) What volume of 0.764 M H2SO4 is required to neutralize 17.1 mL of 0.838 M NaOH? a. b. c. d. e.
9.38 mL 1.31 mL 18.8 mL 17.1 mL 15.6 mL
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ANS: A DIF: moderate OBJ: Calculate the volume of reactant solution needed to neutralize the other reactant. TOP: Using Solutions in Chemical Reactions 117. The complete combustion of heptane, C7H16, yields carbon dioxide and water:
The smallest whole-number coefficient of oxygen in the balanced equation is a. 12. b. 9. c. 13. d. 10. e. 11. ANS: E DIF: easy OBJ: Balance a chemical equation. TOP: Chemical Equations 118. What volume of 2.88 M HCl is required to prepare 689.3 mL of 0.148 M HCl? a. 1.34 104 mL b. 1.62 103 mL c. 35.4 mL d. 0.0282 mL e. 2.94 102 mL ANS: C DIF: easy OBJ: Calculate the volume of concentrated solution to be diluted given molarity concentrated solution, volume dilute solution, and molarity dilute solution. TOP: Dilution of Solutions 119. The commercial production of phosphoric acid, H3PO4, can be represented by the equation
1540 g 296 g 310 g Ca3(PO4)2 + 3SiO2 + 5C +
1120 g 5O2 +
296 g 3H2O
310 g/mol
32.0 g/mol
18.0 g/mol
60.1 g/mol 12.0 g/mol
3CaSiO3 + 5CO2 + 2H3PO4
The molar mass for each reactant is shown below the reactant, and the mass of each reactant for this problem is given above. Which substance is the limiting reactant? a. H2O b. C c. O2 d. Ca3(PO4)2 e. SiO2 ANS: E DIF: moderate OBJ: Identify the limiting reactant. TOP: The Limiting Reactant Concept
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120. If 48.8 g of O2 is mixed with 48.8 g of H2 and the mixture is ignited, what is the maximum
mass of water that may be produced? a. 439 g b. 54.9 g c. 48.8 g d. 98 g e. 86.8 g ANS: B DIF: moderate OBJ: Calculate the theoretical yield of chemical reaction. TOP: Percent Yields from Chemical Reactions 121. A 5.95-g sample of AgNO3 is reacted with BaCl2 according to the equation
2AgNO3(aq) + BaCl2(aq) 2AgCl(s) + Ba(NO3)2(aq) to give 3.36 g of AgCl. What is the percent yield of AgCl? a. 44.6 % b. 33.5 % c. 66.9 % d. 56.5 % e. 100 % ANS: C DIF: moderate OBJ: Determine the percentage yield of a chemical reaction. TOP: Percent Yields from Chemical Reactions 122. The balanced equation for the combustion of ethanol is
C2H5OH(g) + 5O2(g) 3CO2(g) + 4H2O(g) How many grams of oxygen are required to burn 3.9 g of C2H5OH? a. b. c. d. e.
14 g 69 g 2.7 g 36 g 49 g
ANS: A DIF: moderate OBJ: Calculate the mass of one reactant required to consume the other reactant. TOP: Stoichiometry 123. Which of the following aqueous solutions contains the greatest concentration of ions? a. 400.0mL of 0.30M NaCl b. 400.0mL of 0.20M KCH3CO2 c. 400.0mL of 0.10M Al2(SO4)3 d. 400.0mL of 0.20M Na3PO4 e. 400.0mL of 0.60M C2H6O
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ANS: D OBJ: Identify the solution with the highest concentration of ions. TOP: Concentrations of Solutions 124. You need to make an aqueous solution of 0.139M aluminum nitrate, Al(NO3)3 for an
experiment in the lab, using a 300.mL volumetric flask. How much solid aluminum nitrate (Molar Mass = 213.012g/mol) should you add? a. 0.0101g b. 0.0417g c. 1.96g d. 8.88g e. 98.7g ANS: D OBJ: Determine grams of solute from a volume and molarity. TOP: Concentrations of Solutions 125. How many grams of Ag2CO3 (Molar mass = 275.75g/mol) will precipitate when excess
(NH4)2CO3 is added to 75.0 mL of 0.742 M AgNO3 solution? 2AgNO3(aq) + (NH4)2CO3(aq) Ag2CO3(s) + 2NH4NO3(aq) a. 0.202g b. 3.87g c. 7.67g d. 13.6g e. 15.3g ANS: C OBJ: Determine the amount of precipitate given the limiting reactant volume and concentration. TOP: Stoichiometry 126. The concentration of SO32- in a solution is determined by titrating it with a 0.1146M
dichromate solution. The balanced net ionic equation for the reaction is: Cr2O72- + 3SO32- + 8H3O+ 2Cr3+ + 3SO42- + 12H2O In one experiment, 23.84mL of the 0.1146M dichromate solution is required to react completely with 40.00mL of the SO32- solution. Calculate the concentration of the SO32solution. a. 0.02277M b. 0.06830M c. 0.1923M d. 0.2049M e. 0.5768M ANS: D OBJ: Calculate a reactant concentration given the titration results. TOP: Stoichiometry 127. In the laboratory you dissolved 19.7g of barium nitrate, Ba(NO3)2, in a volumetric flask and
added water to a total volume of 125mL. What is the concentration of the nitrate ion in solution? a. 0.0754M b. 0.603M c. 0.791M d. 1.21M e. 1.58M ANS: D OBJ: Calculate the molarity of the anion given solution volume and grams solute. TOP: Concentrations of Solutions 128. You wish to make a 0.339M H2SO4 solution from a stock solution of 12.0M H2SO4. How
much concentrated acid must you add to obtain a total volume of 100.00mL of the dilute solution? a. 0.708mL b. 1.77mL c. 2.83mL d. 3.54mL e. 5.65mL ANS: C OBJ: Determine the volume of concentrated stock required to achieve a given dilution. TOP: Dilution of Solutions
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129. What is the smallest whole number coefficient for sodium hydroxide when the following
equation is balanced? ___Na2SO4 + ___Al(OH)3 ___Al2(SO4)3 + ___NaOH a. 1 b. 2 c. 3 d. 4 e. 6 ANS: E OBJ: Balance the chemical equation. TOP: Chemical Equations 130. What is the smallest whole number coefficient of oxygen when the following molecular
equation is correctly balanced? _____NH3(g) + _____O2(g) _____NO(g) + _____H2O(g) a. 1 b. 2 c. 3 d. 4 e. 5 ANS: E OBJ: Balance the chemical equation. TOP: Chemical Equations 131.
The illustration to the right represents a mixture of oxygen (red) and fluorine (green) molecules. If the molecules react to form OF2 according to the equation: O2 + 2F2 2OF2 How many molecules of OF2 will form?
a. 1
b. 2
c. 3
d. 4
e. 5
ANS: B OBJ: Determine the amount of product given the molecular view before reaction and the balanced equation. TOP: Stoichiometry 132. According to the following reaction, how many grams of hydrogen will be formed upon the
complete reaction of 23.8 grams of sodium with excess water? 2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g) a. 0.512g b. 1.02g c. 1.05g d. 2.09g e. 4.18g ANS: C OBJ: Calculate the grams of product given the grams limiting reagent and the balanced equation. TOP: Stoichiometry 133. 5.57g of hydrogen gas was reacted with excess iodine, according to the following reaction:
H2(g) + I2(g) 2HI(g) If 505g of HI was actually collected, what was the percent yield of HI? a. 14.0% b. 34.9% c. 69.8% d. 71.6% e. 72.1% Whitten 10e
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ANS: D OBJ: Calculate the percent yield given the actual yield and initial reaction conditions. TOP: Percent Yields from Chemical Reactions 134. 61.8g of potassium hydroxide (KOH, Molar Mass=56.108g/mol) is allowed to react with
33.8g of phosphoric acid (H3PO4, Molar Mass = 98.004g/mol), according to the following reaction: 3KOH(aq) + H3PO4(aq) K3PO4(aq) + 3H2O(l) What is the theoretical yield of potassium phosphate (K3PO4, Molar Mass = 212.268g/mol) for this reaction? a. 15.6g b. 16.3g c. 73.2g d. 77.9g e. 233.8g ANS: C OBJ: Calculate the theoretical yield given the initial reaction conditions. TOP: The Limiting Reactant Concept CONCEPTUAL 1. Why is it not possible to determine the limiting reactant by comparing masses of reactants? OBJ: Explain the difference between moles (number of units) and mass with respect to the concept of limiting reactant. TOP: Formula weights, molecular weights, and moles. | The Limiting Reactant Concept 2. What are some reasons that an experiment performed in the lab only produces a yield of 60%? OBJ: List sources of experimental error which reduce percent yield. TOP: Experimental Error. | Precision and Accuracy. 3. Many pharmaceuticals are produced in multi-step reactions with low yields. How does this affect the retail price of these products? How would a research breakthrough that increases yield by 20% affect company profits? OBJ: Explain the effect of increased percent yields (reaction efficiency) on production costs. TOP: Percent Yields from Chemical Reactions | Sequential Reactions 4. Why are many chemical reactions performed in solution instead of the solid phase? Why are many also performed in the gas phase? OBJ: Describe the role of the physical state of reactants in chemical reactions. TOP: Reaction rates. 5. Joining amino acids together to form a peptide is an example of nature using sequential reactions. If each reaction in the series of reactions gives 80% yield, is it practical to try to join 8 of these amino acids together to form a hexapeptide? What would be the expected yield? OBJ: Determine the overall percent yield given the percent yield of each step. | Assess the practicality of this percent yield in synthesis. TOP: Percent Yields from Chemical Reactions | Sequential Reactions
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6. One type of indicator is a molecule that changes color when the acidity of the solution changes. When performing a reaction involving HCl and NaOH, why is it necessary to add an indicator to the solution? OBJ: Explain the purpose of an indicator in an acid base titration. TOP: Reactions of acids and bases.
Chapter 4—The Structure of Atoms MULTIPLE CHOICE 1. Which of the following has no charge? a. nucleus b. neutron c. proton d. electron e. alpha particle ANS: B OBJ: Know the names and charges of the particles that make-up an atom. TOP: Fundamental Particles 2. Which statement about the three fundamental particles is false? a. The charge of a proton is equal in magnitude but opposite in sign to the charge of an electron. b. The mass of an electron or a neutron is very small compared to the mass of a proton. c. Knowledge of the function of these fundamental particles is essential to understanding chemical reactions. d. Atoms consist primarily of protons, neutrons and electrons. e. The fundamental particles are the basic building blocks of atoms. ANS: B OBJ: Know the names, charges, and relative masses of the particles that make-up an atom. TOP: Fundamental Particles 3. The most convincing evidence for the existence of electrons came from ____. a. cathode ray tubes. b. bombarding beryllium with high-energy -particles. c. canal rays. d. the gold foil experiment. e. the Thomson model of the atom. ANS: A OBJ: Understand the importance of the cathode ray tube. TOP: The Discovery of Electrons 4. In interpreting the results of his "oil drop" experiment in 1909, Robert Millikan was able to determine ____. a. the charge on a proton b. that electrically neutral particles (neutrons) are present in the nuclei of atoms c. that the masses of protons and neutrons are nearly identical d. the charge on an electron e. the extremely dense nature of the nuclei of atoms ANS: D Whitten 10e
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OBJ: Understand the purpose of the Millikan's oil drop experiment. TOP: The Discovery of Electrons 5. A graduate student wished to recreate Millikan's "oil drop" experiment. In order to perfect his technique and test his apparatus, he practices performing the experiments many times. If one of his early attempts yielded the following data for the charges on four equal-sized oil drops, what charge per electron would he have calculated and how many electrons were on the drop with the largest number of electrons? 6.60 1019 C 3.30 1019 C 9.90 1019 C 8.25 1019 C a. b. c. d. e.
3.30 1019 C; 3e 3.30 1019 C; 1e 1.10 1019 C; 9e 1.65 1019 C; 6e 1.98 1019 C; 5e
ANS: D OBJ: Calculate the charge of an electron from a Millikan oil drop experiment. TOP: The Discovery of Electrons 6. All of the following statements are about canal rays. Which one is false? a. Canal rays travel toward the cathode. b. Canal rays are created in this reaction: Atom cation + e c. Canal rays consist of positive ions. d. Canal rays led to the discovery of the proton. e. Canal ray particles have e/m ratios many times greater than those of electrons. ANS: E OBJ: Understand the origin and nature of a canal ray. TOP: Canal Rays and Protons 7. Which statement regarding the "gold foil" experiment is false? a. It was performed by Rutherford and his research group early in the 20th century. b. Most of the alpha particles passed through the foil undeflected. c. The alpha particles were repelled by electrons. d. It suggested the nuclear model of the atom. e. It suggested that atoms are mostly empty space. ANS: C OBJ: Know the details and implications of Rutherford's gold foil experiment. TOP: Rutherford and the Nuclear Atom 8. In the Rutherford gold foil experiment, the fact that most of the alpha particles were not deflected as they passed through the gold foil indicates that a. the nucleus is positively charged. b. the atom is mostly empty space. c. atoms are solid spheres touching each other in the solid state. d. gold is very dense. e. none of these is correct. ANS: B OBJ: Know the details and implications of Rutherford's gold foil experiment. TOP: Rutherford and the Nuclear Atom
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9. Ernest Rutherford's model of the atom did not specifically include the ____. a. neutron b. nucleus c. proton d. electron e. electron or the proton ANS: A OBJ: Know the details and implications of Rutherford's gold foil experiment. TOP: Rutherford and the Nuclear Atom 10. The Rutherford "gold foil experiment" suggested ____. a. that electrons have negative charges b. that protons have charges equal in magnitude but opposite in sign to those of electrons c. that atoms have a tiny, positively charged, massive center d. the ratio of the mass of an electron to the charge of the electron e. the existence of canal rays ANS: C OBJ: Know the details and implications of Rutherford's gold foil experiment. TOP: Rutherford and the Nuclear Atom 11. Which of the following statements is false? a. Millikan found the charge of an oil drop always to be in some ratio of 1.6 1019 C. b. Rutherford found that alpha particles were repelled by negatively charged electrons. c. Elements are held together by electrical forces. d. Electrons are attracted to the positive side of an electric field. e. Cathode rays have mass. ANS: B OBJ: Understand nature of a canal ray. | Understand the effect of an electric field on an charged particles. | Know the charge of an alpha particle. | Know the result of Millikan's oil drop experiment. TOP: Rutherford and the Nuclear Atom 12. Which of the following particles has the smallest mass? a. an electron b. a proton c. a neutron d. a hydrogen atom e. an alpha particle ANS: A OBJ: Know the names, charges, and relative masses of the particles that make-up an atom. | Know the charge and composition of an alpha particle. | Know the particles that constitute a hydrogen atom. TOP: Atomic Number 13. Which two subatomic particles have approximately the same mass? a. protons and neutrons b. protons and electrons c. electrons and nuclei d. neutrons and electrons e. protons and alpha particles
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ANS: A OBJ: Know the names, charges, and relative masses of the particles that make-up an atom. TOP: Atomic Number 14. The number of electrons in a neutral atom of an element is always equal to the ____ of the element. a. mass number b. atomic number c. atomic mass unit d. isotope number e. Avogadro's number ANS: B OBJ: Know the definition of atomic number. | Understand the relationship of atomic number to the number of electrons in a neutral atom. TOP: Atomic Number 15. What is a possible explanation for why the neutron was the last of the three fundamental subatomic particles to be discovered? a. The atoms of very few elements contain neutrons in their nuclei. b. Its existence was not suspected until Rutherford's gold foil experiment. c. It was difficult to detect because it has no charge. d. Because its mass is similar to a proton's mass, both are effected similarly by an electric field. e. It is difficult to detect because it is located outside the nucleus with the more numerous, negatively charged electrons. ANS: C OBJ: Know the charge and location in an atom of neutrons. | Understand the effect of an electric field on neutrons. | Know the details and implications of Rutherford's gold foil experiment. TOP: Neutrons 16. Some of the following list match scientists with their contributions to our understanding of the structure of matter. Others do not. Which possible response includes all the correct "matches", and no others? I. Stoney determined that the atomic number of an element is directly proportional to the square root of the reciprocal of the wavelength of a particular x-ray spectral line. II. Davy determined that elements are held together by electrical forces III. Thomson determined ratio of charge to mass for electrons IV. Millikan determined the ratio of proton mass to electron mass V. Chadwick discovered the neutron a. b. c. d. e.
I, II, and IV II, III, and V I, IV, and V II, IV, and V I, II, and III
ANS: B OBJ: Match a discovery related to the structure of matter to the scientist credited with the discovery. TOP: The structure of matter: Important Scientists
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17. The atomic number of an element gives the number of ____ and ____ in the atom while the mass number gives the total number of ____ and ____. a. neutrons; protons; neutrons; electrons b. neutrons; electrons; protons; electrons c. neutrons; electrons; neutrons; protons d. protons; electrons; neutrons; electrons e. protons; electrons; neutrons; protons ANS: E OBJ: Know the definition of atomic number. | Know the definition of atomic mass. TOP: Mass Number and Isotopes 18. The mass number of an atom is the number of ____ in the atom. a. protons b. neutrons c. protons plus the number of electrons d. protons plus the number of neutrons e. electrons plus the number of neutrons ANS: D OBJ: Know the definition of atomic mass. TOP: Mass Number and Isotopes 19. The atomic number of an atom is the number of ____ in the atom. a. protons plus the number of electrons b. neutrons c. protons d. protons plus the number of neutrons e. electrons plus the number of neutrons ANS: C OBJ: Know the definition of atomic number. TOP: Mass Number and Isotopes 20. The difference between the mass number of an atom and the atomic number of the atom is always equal to ____. a. 6.02 1023 b. the atomic number of the element c. the atomic mass unit d. the number of protons in the nucleus e. the number of neutrons in the nucleus ANS: E OBJ: Know the definition of atomic mass. | Know the definition of atomic number. TOP: Mass Number and Isotopes 21. Isotopes are atoms of the same element that a. have different numbers of electrons. b. have different numbers of protons. c. have different atomic numbers. d. have different numbers of neutrons. e. have different nuclear charges.
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ANS: D OBJ: Know the definition of isotope. TOP: Mass Number and Isotopes 22. The atomic number of a certain element is 19, and its atomic weight is 39. An atom of the element contains ____ protons, ____ neutrons, and the chemical symbol for the element is ____. a. 19; 19; F b. 19; 20; F c. 19; 20; K d. 20; 19; K e. none of these ANS: C OBJ: Determine the atom symbol and the number of protons and neutrons given atomic number and atomic weight. TOP: Mass Number and Isotopes 23. Give the number of protons, neutrons, and electrons in an atom of the 90Sr isotope. a. 38 p; 38 n; 38 e b. 38 p; 90 n; 38 e c. 52 p; 38 n; 52 e d. 38 p; 52 n; 38 e e. 90 p; 38 n; 90 e ANS: D OBJ: Determine the number of each fundamental particle in a neutral atom given its atomic mass and symbol. TOP: Mass Number and Isotopes 24. Give the number of protons, neutrons, and electrons of the 128Te2 anion. a. 52 p; 76 n; 52 e b. 52 p; 128 n; 52 e c. 76 p; 52 n; 52 e d. 52 p; 128 n; 54 e e. 52 p; 76 n; 54 e ANS: E OBJ: Determine the number of each fundamental particle in an monatomic ion given its charge, atomic mass, and symbol. TOP: Mass Number and Isotopes 25. Give the number of protons, neutrons, and electrons in an atom of the 41K isotope. a. 19 p; 22 n; 22 e b. 41 p; 19 n; 41 e c. 19 p; 22 n; 19 e d. 19 p; 16 n; 19 e e. 15 p; 26 n; 15 e ANS: C OBJ: Determine the number of each fundamental particle in an atom given its atomic mass and symbol. TOP: Mass Number and Isotopes
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26. Give the number of protons, neutrons, and electrons in the a. 21 p; 20 n; 21 e b. 21 p; 20 n; 18 e c. 21 p; 20 n; 24 e d. 20 p; 21 n; 17 e e. 21 p; 41 n; 18 e
ion.
ANS: B OBJ: Determine the number of each fundamental particle in a monatomic ion given its charge, atomic mass, atomic number, and symbol. TOP: Mass Number and Isotopes 27. Give the number of protons, neutrons, and electrons in the a. 16 p; 18 n; 16 e b. 16 p; 18 n; 14e c. 16 p; 16 n; 19 e d. 16 p; 18 n; 18 e e. 34 p; 16 n; 18 e
ion.
ANS: D OBJ: Determine the number of each fundamental particle in a monatomic ion given its charge, atomic mass, atomic number, and symbol. TOP: Mass Number and Isotopes 28. What is the symbol for an atom composed of 17 protons, 18 neutrons, and is neutral? a. 37Rb b. 20Li c. 37Ca d. 54Xe e. 35Cl ANS: E OBJ: Determine the symbol and atomic mass of a neutral atom given the number of protons and neutrons. TOP: Mass Number and Isotopes 29. What is the symbol for a species composed of 35 protons, 44 neutrons, and 36 electrons? a. b. c. d. e. ANS: E OBJ: Determine the symbol, atomic mass, and charge of an atom given the number of protons, neutrons, and electrons. TOP: Mass Number and Isotopes
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30. What is the symbol for a species composed of 20 protons, 20 neutrons, and 18 electrons? a. 40Ca b. 40Ar c. 34S2 d. 39K+ e. 40Ca2+ ANS: E OBJ: Determine the symbol, atomic mass, and charge of an atom given the number of protons, neutrons, and electrons. TOP: Mass Number and Isotopes 31. What is the symbol for a species composed of 38 protons, 52 neutrons, and 36 electrons? a. 90Kr2+ b. 90Sr2+ c. 90Sr d. 52Kr e. 38Th2+ ANS: B OBJ: Determine the symbol, atomic mass, and charge of an atom given the number of protons, neutrons, and electrons. TOP: Mass Number and Isotopes 32. How many neutrons does the phosphorus isotope a. 8 b. 2 c. 15 d. 17 e. 32
contain?
ANS: D OBJ: Determine the number of neutrons in an atom given its atomic number, atomic mass, and symbol. TOP: Mass Number and Isotopes 33. Consider the 37Cl isotope. An atom of this isotope contains ____ neutrons. a. 17 b. 18 c. 20 d. 37 e. none of these ANS: C OBJ: Determine the number of neutrons in an atom given its atomic mass and symbol. TOP: Mass Number and Isotopes 34. An atom of the 40Ar isotope contains ____ protons. a. 18 b. 20 c. 22 d. 40 e. 19
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ANS: A OBJ: Determine the number of protons in an atom given its atomic mass and symbol. TOP: Mass Number and Isotopes 35. Consider the 40Ar isotope. An atom of this isotope contains ____ neutrons. a. 18 b. 22 c. 32 d. 40 e. none of these ANS: B OBJ: Determine the number of neutrons in an atom given its atomic mass and symbol. TOP: Mass Number and Isotopes 36. The number of ____ can change without changing the element. a. protons only b. neutrons only c. electrons only d. all of these e. neutrons and electrons only ANS: E OBJ: Understand the relationship between the number of protons and the identity of an element. TOP: Mass Number and Isotopes 37. These three species 80Se, 81Br and 82Kr have a. the same atomic mass. b. the same number of protons. c. the same number of neutrons. d. the same mass number. e. the same number of electrons. ANS: C OBJ: Determine the number of each fundamental particle in a neutral atom given its atomic mass and symbol. TOP: Mass Number and Isotopes 38. These three species 1H, 2H and 3H have a. the same atomic mass. b. the same number of protons. c. the same number of neutrons. d. the same mass number. e. the same sum of protons and neutrons. ANS: B OBJ: Determine the number of each fundamental particle in an atom given its atomic mass and symbol. TOP: Mass Number and Isotopes
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39. Consider the following statements about atomic structure. Which is true? a. Isotopes of an element differ only in the number of protons. b. The number of protons in an atom is its atomic number. c. The mass number of an atom is the sum of the number of protons plus electrons in the atom. d. The volume occupied by the nucleus of an atom represents a large percentage of the total volume of the atom. e. The atomic number is the same as the mass number for most elements. ANS: B OBJ: Know the definition of isotope. | Understand the relationship between the number of protons and the identity of an element. | Know the relative volumes of the nucleus of an atom and the entire atom. | Know the definition of atomic mass. TOP: Mass Number and Isotopes 40. Why is the atomic weight of chlorine 35.4527 instead of exactly 35? a. Each chlorine atom has an odd number of protons. b. There are two naturally occurring isotopes of chlorine. c. Each isotope of chlorine has a different number of protons. d. Every atom of chlorine has 18 neutrons. e. Chlorine is a diatomic molecule. ANS: B NAT: Understand the role of isotopes in determining atomic weight. TOP: Mass Spectrometry and Isotopic Abundance 41. Which of the following statements is false? a. Mass spectrometers measure the charge-to-mass ratio of charged particles. b. Mass spectrometers create negative ions by bombarding a gas sample with low energy electrons causing the gas molecules to absorb electrons. c. Mass spectrometers can be used to measure the masses of isotopes. d. In nature some elements exist in only one isotopic form. e. Mass spectrometers can be used to determine isotopic abundance. ANS: B OBJ: Understand how a mass spectrometer works and the data it provides about the elements. TOP: Mass Spectrometry and Isotopic Abundance 42. All of the following describe atomic weights except: a. Atomic weights are based on the mass of the 12C isotope. b. Atomic weights are expressed by an integer, and will differ for different isotopes. c. Atomic weights are determined experimentally. d. Their number values are weighted averages. e. Their number values are shown on the periodic table. ANS: B OBJ: Know the definition of atomic weight. TOP: Mass Spectrometry and Isotopic Abundance
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43. In a mass spectrometry positive ions are produced and then accelerated by an electric field toward a magnetic field. The magnetic field deflects the ions from their straight-line path. The extent to which the beam of ions is deflected depends upon four factors. Which of the following is not one of these factors? a. charges on the particles b. magnetic field strength c. masses of the particles d. diameter of the particles e. magnitude of accelerating voltage (electric field strength) ANS: D OBJ: Understand how a mass spectrometer works. TOP: Mass Spectrometry and Isotopic Abundance 44. Which response lists all the true statements and no false one? I. Cathode rays are deflected away from a positive plate in a cathode ray tube. II. The "canal rays" observed by Goldstein in modified cathode ray tubes were positively charged. III. In a mass spectrometer, a given magnetic field will alter the path of a ion more IV. a. b. c. d. e.
than it will a ion. In nature all elements exist in at least two isotopic forms. I II III I, II, and IV IV
ANS: B OBJ: Understand the origin and nature of a canal ray. | Understand the origin and nature of a cathode ray. | Understand how a mass spectrometer works and the data it provides about the elements. TOP: Mass Spectrometry and Isotopic Abundance 45. What is the atomic weight of a hypothetical element consisting of two isotopes, one with mass = 64.23 amu (26.00%), and one with mass = 65.32 amu? a. 65.16 amu b. 64.37 amu c. 64.96 amu d. 65.04 amu e. 64.80 amu ANS: D OBJ: Use isotopic abundance and atomic mass data to calculate the atomic weight of an element. TOP: The Atomic Weight Scale and Atomic Weights
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46. If an element consisted of three isotopes in the following relative abundance, what would the atomic weight of the element be? This is a hypothetical example. 30.00% 50.00% 20.00% a. b. c. d. e.
37.00 amu 38.00 amu 40.00 amu
38.00 amu 38.10 amu 38.20 amu 39.98 amu none of these
ANS: B OBJ: Use isotopic abundance and atomic mass data to calculate the atomic weight of an element. TOP: The Atomic Weight Scale and Atomic Weights 47. A hypothetical element consists of the following naturally occurring isotopes. What is the atomic weight of the element? Isotopes 1 2 3 a. b. c. d. e.
Mass 46.041 amu 47.038 amu 49.034 amu
Abundance 26.00% 58.00% 16.00%
46.78 amu 46.89 amu 47.02 amu 47.10 amu 47.24 amu
ANS: D OBJ: Use isotopic abundance and atomic mass data to calculate the atomic weight of an element. TOP: The Atomic Weight Scale and Atomic Weights 48. Suppose a hypothetical element consists of the following four isotopes. Calculate its atomic weight. Mass 62.982 amu 63.978 amu 64.973 amu 65.968 amu a. b. c. d. e.
Natural Abundance 14.260% 31.660% 8.180% 45.900%
64.831 amu 64.822 amu 64.816 amu 64.808 amu 64.802 amu
ANS: A OBJ: Use isotopic abundance and atomic mass data to calculate the atomic weight of an element. TOP: The Atomic Weight Scale and Atomic Weights
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49. A hypothetical element consists of four isotopes having the following percentage natural abundance and isotopic masses. What is its atomic weight? isotope 1: 16.06% (52.100 amu); isotope 2: 28.36% (53.097 amu); isotope 3: 42.60% (54.093 amu); isotope 4: 12.98% (55.090 amu). a. 53.182 amu b. 53.262 amu c. 53.314 amu d. 53.487 amu e. 53.620 amu ANS: E OBJ: Use isotopic abundance and atomic mass data to calculate the atomic weight of an element. TOP: The Atomic Weight Scale and Atomic Weights 50. Gallium has two naturally occurring isotopes. 69Ga (68.9257 amu) is the more abundant isotope, at 60.4%. If the atomic mass of gallium is 69.723 amu, what is the mass of the other isotope, 71Ga? a. 71 amu b. 71.512 amu c. 39.60 amu d. 69.985 amu e. 70.925 amu ANS: E OBJ: Use isotopic abundance, atomic mass, and atomic weight to calculate the atomic mass of an isotope. TOP: The Atomic Weight Scale and Atomic Weights 51. Nitrogen (atomic mass = 14.0067 amu) has two naturally occurring isotopes. The masses of 14N and 15 N are 14.003074 and 15.000108 amu, respectively. What is the percent abundance of 15N? a. 15.0001% b. 14.0031% c. 99.635% d. 0.365% e. 0.0104% ANS: D OBJ: Use atomic mass and atomic weight to calculate isotopic abundance. TOP: The Atomic Weight Scale and Atomic Weights 52. The atomic weight of silver is 107.868 amu. Naturally occurring silver consists of two isotopes: 107Ag (mass = 106.904 amu) and 109Ag (mass = 108.905 amu). What percentage of naturally occurring silver is the heavier isotope? a. 52.6% b. 45.4% c. 48.2% d. 51.7% e. 62.7% ANS: C OBJ: Use atomic mass and atomic weight to calculate isotopic abundance. TOP: The Atomic Weight Scale and Atomic Weights
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53. A hypothetical element has an atomic weight of 48.68 amu. It consists of three isotopes having masses of 47.00 amu, 48.00 amu, and 49.00 amu. The lightest-weight isotope has a natural abundance of 10.0%. What is the percent abundance of the heaviest isotope? a. 66.0% b. 12.0% c. 18.0% d. 72.0% e. 78.0% ANS: E DIF: Harder Question OBJ: Use atomic mass, atomic weight, and limited isotopic abundance data to calculate isotopic abundance. TOP: The Atomic Weight Scale and Atomic Weights 54. The atomic weight of antimony is 121.76 amu. There are two naturally occurring isotopes of antimony. 121Sb has an isotopic mass of 120.9038 amu and has a natural abundance of 57.40%. What is the isotopic mass of the other isotope, 123Sb? a. 122.4 amu b. 122.9 amu c. 122.2 amu d. 123.2 amu e. 123.1 amu ANS: B OBJ: Use isotopic abundance, atomic mass, and atomic weight to calculate the atomic mass of an isotope. TOP: The Atomic Weight Scale and Atomic Weights 55. The atomic weight of rubidium is 85.4678 amu. Rubidium consists of two isotopes: 85Rb (72.15%) and 87 Rb (27.85%). The mass of an atom of 85Rb is 84.9117 amu. What is the mass of an atom of 87Rb? a. 86.7271 amu b. 86.8013 amu c. 86.8220 amu d. 86.8621 amu e. 86.9085 amu ANS: E OBJ: Use isotopic abundance, atomic mass, and atomic weight to calculate the atomic mass of an isotope. TOP: The Atomic Weight Scale and Atomic Weights 56. The five isotopes of nickel occur in the following percentages with the following isotopic masses. The atomic weight is 58.69 amu. What is the isotopic mass of 60Ni? (Choose the closest answer.) Isotope 58 Ni 60 Ni 61 Ni 62 Ni 64 Ni
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% 68.27 26.10 1.13 3.59 0.91
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a. b. c. d. e.
59.31 amu 58.24 amu 58.62 amu 60.57 amu 59.93 amu
ANS: E DIF: Harder Question OBJ: Use isotopic abundance, atomic mass, and atomic weight to calculate the atomic mass of an isotope. TOP: The Atomic Weight Scale and Atomic Weights Chapter 4 Values The following values may be useful for solving some of the problem(s) below. speed of light = 3.00 108 m/s Planck's constant = 6.63 1034 Js
1 joule = 1 kgm2/s2 1 Ångstrom = 1 1010 m
57. All of the following are true statements about electromagnetic radiation (light) except? a. As wavelength increases frequency decreases. b. As energy increases frequency decreases. c. As wavelength increases energy decreases. d. The product of wavelength and frequency is constant. e. Amplitude is independent of frequency. ANS: B OBJ: Understand the relationship between frequency of light and wavelength. | Understand the relationship between energy of light and frequency. | Understand the relationship between energy of light and wavelength. | Understand the term amplitude with respect to light. TOP: Electromagnetic Radiation 58. Which statement about electromagnetic radiation is false? a. As frequency increases, wavelength decreases. b. As wavelength increases, energy increases. c. As wavelength increases, frequency decreases. d. Wavelength and frequency are inversely proportional. e. Wavelength and energy are inversely proportional. ANS: B OBJ: Understand the relationship between frequency of light and wavelength. | Understand the relationship between energy of light and wavelength. TOP: Electromagnetic Radiation 59. Two hundred wave cycles occur in 50 seconds. What is the frequency of this wave? a. 50 Hz b. 200 Hz c. 4 Hz d. 0.25 Hz e. 10000 Hz ANS: C OBJ: Calculate a frequency given the number of cycles and time. TOP: Electromagnetic Radiation
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60. What is the frequency of light having a wavelength of 4.50 106 cm? a. 2.84 1012 s1 b. 2.1 104 s1 c. 4.29 1014 s1 d. 1.06 1022 s1 e. 6.67 1015 s1 ANS: E OBJ: Calculate a frequency given wavelength in centimeters. TOP: Electromagnetic Radiation 61. What is the frequency of light of wavelength 7000 Å? a. 8.41 1015 s1 b. 4.72 1014 s1 c. 2.48 1013 s1 d. 6.67 1015 s1 e. 4.29 1014 s1 ANS: E OBJ: Calculate a frequency given wavelength in angstroms. TOP: Electromagnetic Radiation 62. A tanning booth uses ultraviolet light at a wavelength of 1000. Å. What is the frequency of this light? a. 3.3 1016 s1 b. 6.63 1016 s1 c. 2.48 1013 s1 d. 1.5 1026 s1 e. 3.0 1015 s1 ANS: E OBJ: Calculate a frequency given wavelength in angstroms. TOP: Electromagnetic Radiation 63. A police officer is measuring traffic speed with radar operating at 1.0 109 Hz. What is the wavelength of this electromagnetic energy? a. 0.30 m b. 0.30 nm c. 0.30 Å d. 3.30 m e. 3 1017 m ANS: A OBJ: Calculate a wavelength in units of angstroms, meters, or nanometers, given frequency. TOP: Electromagnetic Radiation 64. The amount of energy possessed by a photon is all of the following except? a. Dependent on the wavelength. b. Is a particular amount called a quantum. c. Is described by Planck's equation. d. Is inversely proportional to frequency. e. Is not dependent on the amplitude of the wave.
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ANS: D OBJ: Define photon and quantum with respect to energy, wavelength, amplitude, and frequency of light. TOP: Electromagnetic Radiation 65. What is the wavelength of yellow light having a frequency of 5.17 1014 Hz? a. 3.60 1010 m b. 1.55 1023 m c. 6.45 1028 m d. 5.80 107 m e. 2.72 106 m ANS: D OBJ: Calculate a wavelength given frequency. TOP: Electromagnetic Radiation 66. What is the wavelength in Ångstroms of radiation used by an x-ray technician, with a frequency of 6.00 1018 s1? a. 0.50 Å b. 2.00 Å c. 1.80 1017 Å d. 3.98 105 Å e. 5.56 1018 Å ANS: A OBJ: Calculate a wavelength in units of angstroms given frequency. TOP: Electromagnetic Radiation 67. What is the wavelength of green light having a frequency of 6.10 1014 Hz? a. 1.67 10 Å b. 1.07 1017 Å c. 4.92 103 Å d. 2.38 1013 Å e. 6.61 108 Å ANS: C OBJ: Calculate a wavelength in units of angstroms given frequency. TOP: Electromagnetic Radiation 68. A tanning booth uses ultraviolet light at a wavelength of 1000. Å. Visible light from the sun averages about 5000. Å. What is ratio of the energy of the UV to the visible light, E5000Å/E1000Å? a. 50.00 b. 5.000 c. 500.0 d. 1000. e. 0.2000 ANS: B OBJ: Calculate the energy of light at two different wavelengths given in angstroms. | Determine the ratio of the two energies. TOP: Electromagnetic Radiation
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69. What is the energy, in J/photon, of ultraviolet light with a frequency of 2.70 1016 Hz? a. 6.00 108 J/photon b. 8.00 106 J/photon c. 2.46 1018 J/photon d. 4.07 1019 J/photon e. 1.79 1017 J/photon ANS: E OBJ: Calculate the energy of light given frequency. TOP: Electromagnetic Radiation 70. Calculate the energy (J/photon) of a photon of wavelength 3.65 106 m. a. 5.45 1020 J b. 1.82 1028 J c. 1.22 1014 J d. 6.05 1037 J e. none of these ANS: A OBJ: Calculate the energy of light given wavelength in meters. TOP: Electromagnetic Radiation 71. Radio waves are very low energy forms of electromagnetic radiation. What is the energy of a photon of radio waves with a wavelength of 150. m? a. 3.30 1027 J b. 1.33 1027 J c. 1.10 1017 J d. 1.38 1026 J e. 2.22 1019 J ANS: B OBJ: Calculate the energy of light given wavelength in meters. TOP: Electromagnetic Radiation 72. What is the energy in joules of a photon of light of wavelength 3.75 103 Å? a. 3.30 1013 J b. 5.30 1019 J c. 1.10 1017 J d. 1.38 1014 J e. 2.22 1011 J ANS: B OBJ: Calculate the energy of light given wavelength in angstroms. TOP: Electromagnetic Radiation 73. The energy of a photon of light is 1.5 1020 J. What is its wavelength? a. 4.67 104 Å b. 1.33 105 Å c. 5.12 104 Å d. 6.25 105 Å e. 7.60 103 Å
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114
ANS: B OBJ: Calculate the wavelength of light in angstroms given energy. TOP: Electromagnetic Radiation 74. Which statement regarding the photoelectric effect is false? a. Electrons can be ejected only if the light is of sufficiently short wavelength. b. The current increases with increasing intensity of the light. c. Electrons can be ejected only if the light is of sufficiently high energy. d. The current does not depend on the color of the light as long as the wavelength is short enough. e. The wavelength limit sufficient for the ejection of electrons is the same for all metals. ANS: E OBJ: Understand the photoelectric effect. TOP: The Photoelectric Effect 75. Who developed an explanation for the photoelectric effect? a. Einstein b. Planck c. Rutherford d. Millikan e. Bohr ANS: A OBJ: Know who explained the photoelectric effect. TOP: The Photoelectric Effect 76. The Rydberg equation is an empirical equation that describes mathematically ____. a. the lines in the emission spectrum of hydrogen b. the results of the oil drop experiment c. the results of the cathode ray experiments d. the Bohr model of the atom e. the possible paths of two isotopes of the same element in a mass spectrometer ANS: A OBJ: Understand the Rydberg equation. TOP: Atomic Spectra and the Bohr Atom 77. Which one of the following statements is not consistent with the Bohr theory? a. An atom has a number of discrete energy levels (orbits) in which an electron can exist as long as it continually emits radiation of a definite energy. b. An electron may move to a lower energy orbit by emitting radiation of frequency proportional to the energy difference between the two orbits. c. An electron may move to a higher energy orbit by absorbing radiation of frequency proportional to the energy difference between the two orbits. d. An electron moves in a circular orbit around the nucleus. e. The energy of an electron is quantized. ANS: A OBJ: Understand the Bohr model of the atom and its limits. TOP: Atomic Spectra and the Bohr Atom
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78. One of the spectral lines in the emission spectrum of mercury has a wavelength of 6.234 107 m. What is the frequency of the line? a. 4.81 106 s1 b. 1.87 1014 s1 c. 4.81 1014 s1 d. 6.45 1011 s1 e. 1.87 106 s1 ANS: C OBJ: Calculate a frequency given wavelength in meters. TOP: Atomic Spectra and the Bohr Atom 79. The emission spectrum of mercury shows a line of wavelength 579 nm. How much energy is emitted as the excited electron falls to a lower energy level? a. 3.43 1019 J/atom b. 1.07 1020 J/atom c. 6.05 1019 J/atom d. 3.60 1020 J/atom e. 5.16 1020 J/atom ANS: A OBJ: Understand the origin of an emission line. | Calculate the energy of light given wavelength in nanometers. TOP: Atomic Spectra and the Bohr Atom 80. When sodium compounds are heated in a bunsen burner flame, they emit light at a wavelength of 5890 Å. If 1.0 104 mole of sodium atoms each emit a photon of this wavelength, how many kilojoules of energy are emitted? a. 1.21 kJ b. 2.03 103 kJ c. 2.03 102 kJ d. 8.08 103 kJ e. 6.20 102 kJ ANS: C OBJ: Calculate total kilojoules energy given wavelength in angstroms and moles of photons. TOP: Atomic Spectra and the Bohr Atom 81. One of the spectral lines in the emission spectrum of mercury has a wavelength of 6.234 107 m. How much energy is emitted if 1.00 mole of mercury atoms emits light of 6.234 107 m? Express your answer in kJ/mol. a. 127 kJ/mol b. 485 kJ/mol c. 192 kJ/mol d. 5.56 101 kJ/mol e. 1.74 101 kJ/mol ANS: C OBJ: Calculate the energy of light in kilojoules per mole given wavelength in meters. TOP: Atomic Spectra and the Bohr Atom
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82. When an electron of an excited hydrogen atom falls from level n = 2 to level n = 1, what wavelength of light is emitted? R = 1.097 107 m1 a. 18.2 Å b. 970 Å c. 4800 Å d. 1215 Å e. 1820 Å ANS: D DIF: Harder Question OBJ: Calculate the wavelength of light, in angstroms from an n = 2 to n = 1 hydrogen emission. TOP: Atomic Spectra and the Bohr Atom 83. An electron of mass 9.11 1028 g is traveling at 2.50 106 m/s. Calculate its de Broglie wavelength (in Å). a. 0.029 Å b. 345 Å c. 0.14 Å d. 2.91 Å e. 2.90 103 Å ANS: D OBJ: Calculate the de Broglie wavelength in angstroms given mass in grams and velocity in meters per second. TOP: The Wave Nature of the Electron 84. An alpha particle of mass 4.0026 amu has a velocity of 10.0% of the speed of light. What is its de Broglie wavelength (in m)? a. 3.32 1015 m b. 3.30 1018 m c. 1.22 1015 m d. 3.70 1016 m e. 3.50 1021 m ANS: A DIF: Harder Question OBJ: Calculate the de Broglie wavelength in meters given mass in amu and velocity as a percentage of the speed of light. TOP: The Wave Nature of the Electron 85. What is the velocity of a neutron of mass 1.67 1027 kg that has a de Broglie wavelength of 2.05 Å? a. 19 m/s b. 1.94 103 m/s c. 8.13 107 m/s d. 1.93 104 m/s e. 5.16 104 m/s ANS: B OBJ: Calculate velocity in meters per second given mass in kilograms and the de Broglie wavelength in angstroms. TOP: The Wave Nature of the Electron
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86. What is the de Broglie wavelength of a 16.0 lb shotput moving at a velocity of 7.26 m/s? a. 1.30 1038 m b. 1.85 1030 m c. 1.26 1035 m d. 2.60 1036 m e. 6.63 1031 m ANS: C OBJ: Calculate the de Broglie wavelength in meters given mass in pounds and velocity in meters per second. TOP: The Wave Nature of the Electron 87. What is the de Broglie wavelength of a 2.00-ton truck moving at a velocity of 60.0 mph? a. 1.36 1038 m b. 2.76 1039 m c. 9.79 1036 m d. 6.18 1039 m e. 4.49 1032 m ANS: A OBJ: Calculate the de Broglie wavelength in meters given mass in tons and velocity in miles per hour. TOP: The Wave Nature of the Electron 88. Which match is incorrect? a. de Broglie / predicted that electrons have wave-like properties b. Rutherford / showed that most of the mass of an atom is in its nucleus c. Thomson / demonstrated the existence of the neutron d. Faraday / proposed that the elements of a chemical compound are held together by electrical forces e. Millikan / determined the magnitude of the charge on an electron ANS: C OBJ: Match a discovery to the scientist credited with the discovery. TOP: The Wave Nature of the Electron 89. The Heisenberg Uncertainty Principle states that ____. a. no two electrons in the same atom can have the same set of four quantum numbers. b. two atoms of the same element must have the same number of protons. c. it is impossible to determine accurately both the position and momentum of an electron simultaneously. d. electrons of atoms in their ground states enter energetically equivalent sets of orbitals singly before they pair up in any orbital of the set. e. charged atoms (ions) must generate a magnetic field when they are in motion. ANS: C OBJ: Know the Heisenberg Uncertainty Principle. TOP: The Quantum Mechanical Picture of the Atom
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90. What statement regarding quantum numbers is false? a. The spin quantum number has values of either +1 or 1. b. The principle quantum number has only integer values. c. The angular momentum quantum number also has letter designations. d. The magnetic quantum number has its values restricted by the l quantum number. e. The magnetic quantum number is represented by ml. ANS: A OBJ: Define the four quantum numbers. TOP: The Quantum Mechanical Picture of the Atom 91. Which response includes all the following statements that are true, and no others? I. When an electron falls to a lower energy level in an atom, it emits electromagnetic radiation. II. The energy of electromagnetic radiation is directly proportional to its frequency. III. The product of wavelength and the speed of light is frequency. IV. Atoms can exist only in certain energy states. a. b. c. d. e.
I I and III II II and III I, II, and IV
ANS: E OBJ: Understand the relationship between energy of light and frequency. | Understand the relationship between frequency of light and wavelength. | Understand emission with respect to light. | Understand the effect of electron energy levels on the possible energy states of an atom. TOP: The Quantum Mechanical Picture of the Atom 92. A(n) ____ is a region of space in which there is a high probability of finding an electron in an atom. a. shell b. atomic orbital c. core d. major energy level e. nucleus ANS: B OBJ: Recognize the definition of atomic orbital. TOP: Quantum Numbers 93. The general shape of the region in space occupied by electrons is described by which quantum number? a. n b. l c. ml d. ms e. ANS: B OBJ: Recognize and understand the role of each quantum number in describing electrons in an atom. TOP: Quantum Numbers
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94. Which statement about the four quantum numbers is false? a. n = principal quantum number, n = 1,2,3, . . . b. l = angular momentum quantum number, l = 0,1,2,3, . . ., (n+1) c. ml = magnetic quantum number, ml = (l), . . .,0,. . ., (+l) d. ms = spin quantum number, ms = ± e. The values of n, l, and ml describe a particular atomic orbital. ANS: B OBJ: Know the symbol, name, numerical limits, and purpose of the four quantum numbers. TOP: Quantum Numbers 95. Which response lists all the true statements about the four quantum numbers? I. n = principal quantum number, n = 1,2,3, . . . II. l = angular momentum quantum number, l = 0,1,2,3, . . ., (n1) III. ml = magnetic quantum number, ml = 0, 1, . . ., l IV. a. b. c. d. e.
ms = spin quantum number,
ms = ±
I, II, and IV I, II, and III I and III II and III II, III, and IV
ANS: A OBJ: Know the symbol, name, and numerical limits of the four quantum numbers. TOP: Quantum Numbers 96. Which quantum number is often designated by the letters s, p, d and f? a. n b. l c. ml d. ms e. ANS: B OBJ: Recognize and understand the role of each quantum number in describing electrons in an atom. TOP: Quantum Numbers 97. The principal quantum number of an orbital is n = 1. This must be a(n) ____ orbital. a. s b. p c. d d. f e. g ANS: A OBJ: Match the principal quantum number with a suborbital designation (shape). TOP: Quantum Numbers
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98. The orientation in space of an orbital is designated by which quantum number? a. n b. l c. ml d. ms e. ANS: C OBJ: Recognize and understand the role of each quantum number in describing electrons in an atom. TOP: Quantum Numbers 99. Which statement is false? a. The third shell (or major energy level) with n = 3 has no f orbitals. b. There are 10 d orbitals in a set. c. A set of p orbitals can accommodate a maximum of 6 electrons. d. None of the p orbitals are spherically symmetric. e. The fifth shell (or major energy level) has one set of f orbitals. ANS: B OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 100. Which of the following statements is false? a. A set of p orbitals in a given energy level are equal in energy. b. The 5d and 4f orbitals are very close in energy. c. The 4s orbitals are lower in energy the 3d orbitals. d. An f set of orbitals is filled with 10 electrons. e. The third energy level has 5 d orbitals. ANS: D OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 101. What is the total number of electrons in the fifth energy level (n = 5). a. 16 b. 32 c. 25 d. 50 e. 18 ANS: D OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals
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121
102. Which response includes all the following statements that are true, and no others? I. An s orbital can accommodate a maximum of two electrons. II. A set of d orbitals can accommodate a maximum of ten electrons. III. Each d orbital within a set consists of two lobes, 180 apart. IV. There are nine f orbitals in a set of f orbitals. a. b. c. d. e.
I, III, and IV I and II II and IV II, III, and IV I and IV
ANS: B OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 103. The maximum number of electrons that can occupy an energy level or shell (n = principle quantum number) is ____. a. n b. 2n c. n + 1 d. n 1 e. 2n2 ANS: E OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 104. Which response includes all the following statements that are true, and no false statements? I. Each set of d orbitals contains 7 orbitals. II. Each set of d orbitals can hold a maximum of 14 electrons. III. The first energy level contains only s and p orbitals. IV. The s orbital in any shell is always spherically symmetrical. a. b. c. d. e.
I and II I, III, and IV IV II and IV III
ANS: C OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 105. The third energy level or shell of an atom can hold a maximum of ____ electrons. a. 8 b. 2 c. 16 d. 18 e. 25
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ANS: D OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 106. The total number of electrons that can be accommodated in the 4th shell is ____. a. 8 b. 2 c. 18 d. 32 e. 50 ANS: D OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 107. Which of the following is not a valid magnetic quantum number for the 3d set of orbitals? a. 1 b. 2 c. 0 d. 2 e. 3 ANS: E OBJ: Understand the limits of each quantum number in describing the location, relative energies, and number of electrons in an atom. TOP: Atomic Orbitals 108. Identify the following orbital.
a. b. c. pz d. dxy e. fz ANS: B OBJ: Match an orbital label to a drawing of an orbital. TOP: Atomic Orbitals
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109. What is the value of the angular momentum quantum number, l, for the following orbital?
a. b. c. d. e.
1 0 1 2
ANS: D OBJ: Match a value of the angular momentum quantum number to an orbital drawing. TOP: Atomic Orbitals 110. What is the value of the angular momentum quantum number, l, for the following orbital?
a. b. c. d. e.
1 0 1 2
ANS: E OBJ: Match a value of the angular momentum quantum number to an orbital drawing. TOP: Atomic Orbitals 111. No two electrons in the same atom can have the same set of four quantum numbers is a statement of ____. a. the Aufbau Principle b. the Pauli Exclusion Principle c. Dalton's Theory d. Hund's Rule e. the Heisenberg Uncertainty Principle ANS: B OBJ: Match the name of a principle, rule, or theory to a given definition. TOP: Electron Configurations 112. All orbitals of a given degenerate set must be singly occupied before pairing begins in that set is a statement of ____. a. the Heisenberg Uncertainty Principle b. the Bohr Theory c. the Aufbau Principle d. Planck's Theory e. Hund's Rule
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ANS: E OBJ: Match the name of a principle, rule, or theory to a given definition. TOP: Electron Configurations 113. Which element has the electron configuration below? 1s22s22p63s23p63d104s24p3 a. b. c. d. e.
V Ca P As Se
ANS: D OBJ: Match the atom symbol with the given ground state electron configuration. TOP: Electron Configurations 114. The electron configuration 1s22s22p63s23p64s23d6 represents the element ____. a. Mn b. Se c. Fe d. Co e. Kr ANS: C OBJ: Match the atom symbol with the given ground state electron configuration. TOP: Electron Configurations 115. If an element has the following electron configuration, what is the symbol for the element?
a. b. c. d. e.
Al Si P S Cl
ANS: E OBJ: Match the atom symbol with the given ground state electron configuration. TOP: Electron Configurations 116. What is the electron configuration of sulfur, S? a. 1s22s22p63s23p2 b. 1s21p62s22p4 c. 1s21p62s22p2 d. 1s22s22p62d4 e. 1s22s22p63s23p4 ANS: E OBJ: Match the ground state electron configuration with the given atom symbol. TOP: Electron Configurations
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117. Which of the following is the electron configuration of P in its ground state? a. 1s21p62s22p6 b. 1s22s22p33p33d4 c. 1s22s22p33s23p2 d. 1s22s22p63s23p3 e. 1s22s22p43s23p4 ANS: D OBJ: Match the ground state electron configuration with the given atom symbol. TOP: Electron Configurations 118. Which of the following is the electron configuration of F? a. 1s21p62s22p6 b. 1s22s22p4 c. 1s22s22p6 d. 1s22s22p5 e. 1s22s22p43s23p6 ANS: C OBJ: Match the ground state electron configuration with the given monatomic ion. TOP: Electron Configurations 119. What is the electron configuration of tellurium, 52Te? a. 1s22s22p63s23p64s23d104p65s24d104f 2 b. 1s22s22p63s23p64s23d104p64f14 c. 1s22s22p63s23p64s23d104p65s24d105p4 d. 1s22s22p63s23p64s23d104p65s24d105p66s25d4 e. 1s22s22p62d103s23p64s23d104p65s25p2 ANS: C OBJ: Match the ground state electron configuration with the given element. TOP: Electron Configurations 120. What is the electron configuration of tin, Sn? a. [Kr]5s23d103f145p4 b. [Kr]5s23d104d145p4 c. [Kr]5s23d104f145p2 d. [Kr]5s24d105p2 e. [Xe]5s24d105p2 ANS: D OBJ: Match the ground state electron configuration with the given element. TOP: Electron Configurations 121. What is the electron configuration of In? a. 1s22s22p63s23p63d104s24p64d105s2 b. 1s22s22p63s22d103p64s23d104p64d105s25p1 c. 1s22s22p63s23p63d104s24p64d105s25p1 d. 1s22s22p63s22d103p64s23d104p65s24d1 e. 1s22s22p63s23p63d104s24p64d115s2 ANS: C OBJ: Match the ground state electron configuration with the given atom symbol. TOP: Electron Configurations
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122. Which one of the following electron configurations is incorrect? a. 9F / 1s22s22p5 b. 12Mg / [Ne]3s2 c. 17Cl / [Ne]3s23p5 d. 6C / [He]2s22p4 e. 19K / 1s22s22p63s23p64s1 ANS: B OBJ: Match the ground state electron configuration and the atom symbol. TOP: Electron Configurations 123. Which one of the following electron configurations is incorrect? a. Cl / 1s22s22p63s23p6 b. Ge / [Ar]3d104s23p3 c. Sc / [Ar]3d14s2 d. C / [He]2s22p4 e. N3 / 1s22s22p6 ANS: B OBJ: Match the ground state electron configuration and the atom symbol. | Match the ground state electron configuration and the monatomic ion. TOP: Electron Configurations 124. Which one of the following ground state electron configurations is incorrect? a. 20Ca / 1s22s22p63s23p64s2 b. 25Mn / [Ar]4s24d5 c. 29Cu / [Ar]3d104s1 d. 50Sn / [Kr]4d105s25p2 e. 54Xe / [Kr]4d105s25p6 ANS: B DIF: Harder Question OBJ: Match the ground state electron configuration and the atom symbol. TOP: Electron Configurations 125. What is the electron configuration of the iron(III) ion? a. Fe3+[Ar]4s23d3 b. Fe3+[Ar]3d5 c. Fe2+[Ar]4s23d3 d. Fe2+[Ar]3d5 e. Fe3+[Kr]3d5 ANS: B OBJ: Determine the symbol, charge, and ground state electron configuration of an ion given its name. TOP: Electron Configurations 126. What element has the following electron configuration? [Ar]4d104s24p5 a. b. c. d. e.
Br I Cl At none of these
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ANS: E OBJ: Match the atom symbol with the given ground state electron configuration. TOP: Electron Configurations 127. If the following set of quantum numbers represents the "last" electron added to complete the ground state electron configuration of an element according to the Aufbau Principle, which one of the following could be the symbol for the element? n = 3, l = 1, ml = 0, ms = ± a. b. c. d. e.
Na V Zn Si Th
ANS: D OBJ: Express the given principle quantum numbers of the last electron added to an unspecified electron configuration as an element symbol. TOP: Electron Configurations 128. If the following set of quantum numbers represents the "last" electron added to complete the ground state electron configuration of an element according to the Aufbau Principle, which one of the following could be the symbol for the element? n = 4, l = 1, ml = 1, ms = ± a. b. c. d. e.
Ca Ga Sc Y K
ANS: B OBJ: Express the given principle quantum numbers of the last electron added to an unspecified electron configuration as an element symbol. TOP: Electron Configurations 129. Which of the following sets of quantum numbers could represent the highest energy electron in V2+?
a. b. c. d. e.
n
l
ml
ms
4
0
0
4
1
1
3
2
1
3
1
0
+
4
2
1
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ANS: C OBJ: Identify the set of four quantum numbers consistent with the highest energy electron in the given ion. TOP: Electron Configurations 130. Which statement is false? a. If an electron has quantum number n = 3, the electron could be in a d sublevel. b. If an electron has quantum number l = 2, the only possible values of ml are 0 and 1. c. If an electron has ml = 1, it might be in a p, d, or f sublevel but not in an s sublevel. d. An electron that has n = 3 cannot be in an f sublevel. e. An electron that has n = 5 could be in an s, p, d, or f sublevel. ANS: B OBJ: Apply the symbol, name, and numerical limits of the four quantum numbers. TOP: Electron Configurations 131. Which one of the following statements is false? a. If an electron has quantum number n = 2, it may be in a p sublevel. b. If an electron has l = 1, it must be in a p sublevel. c. Two electrons in the same atom may have quantum numbers, n, l, ml , ms of 2, 1, 1, 1/2, and 2, 1, 1, 1/2. d. Two electrons in the same atom may not have quantum numbers of 2, 1, 1, 1/2 and 2, 1, 1, 1/2. e. If an electron has n = 1, it must be in an s orbital. ANS: C OBJ: Apply the symbol, name, and numerical limits of the four quantum numbers. TOP: Electron Configurations 132. What statement is false? a. A set of p orbitals in a specific energy level always fills before the d orbitals in the same energy level are occupied. b. There are five d orbitals per major energy level (shell) beginning with the fourth energy level. c. A sample of chromium is attracted toward a magnetic field. d. A sample of beryllium is weakly repelled by a magnetic field. e. A set of d orbitals can accommodate as many as ten electrons. ANS: B DIF: Harder Question OBJ: Know the orbital filling order. | Connect behavior of an atom in a magnetic field to electron configuration. | Apply the symbol, name, and numerical limits of the four quantum numbers. TOP: Electron Configurations 133. Paramagnetism is characteristic of systems containing ____. a. no unpaired electrons b. only p electrons as valence electrons c. one or more unpaired electrons d. only d electrons as valence electrons e. only s electrons as valence electrons ANS: C OBJ: Define paramagnetism. TOP: Paramagnetism and Diamagnetism
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134. How many unpaired electrons are there in a neutral iodine atom (element 53)? a. one b. two c. three d. four e. five ANS: A OBJ: Determine the number of unpaired electrons in a given atom. TOP: Paramagnetism and Diamagnetism 135. Which of the following atoms has one unpaired electron in its ground state? a. Co b. Ga c. Ca d. As e. C ANS: B OBJ: Determine the number of unpaired electrons in a given atom. TOP: Paramagnetism and Diamagnetism 136. Which of the following atoms has the greatest number of unpaired electrons in its ground state? a. Fe b. N c. S d. Ti e. Cu ANS: A OBJ: Determine the number of unpaired electrons in a given atom. TOP: Paramagnetism and Diamagnetism 137. Which of the following atoms or ions is not diamagnetic? a. Cl b. Cd c. Ca d. Na+ e. B ANS: E OBJ: Determine whether an atom or ion is paramagnetic or diamagnetic. TOP: Paramagnetism and Diamagnetism 138. Which one of the following elements is paramagnetic in its ground state? a. He b. Ge c. Kr d. Hg e. Mg ANS: B OBJ: Determine whether an atom or ion is paramagnetic or diamagnetic. TOP: Paramagnetism and Diamagnetism
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139. Which are the only free elements that exhibit ferromagnetism? a. iron, ruthenium and osmium b. iron, manganese and cobalt c. iron, cobalt and nickel d. iron only e. none of these ANS: C OBJ: Identify which elements exhibit ferromagnetism. TOP: Paramagnetism and Diamagnetism 140. The number of electrons present in the s orbitals in the outermost electron shell of the Group IA metals is ____. a. one b. two c. three d. four e. five ANS: A OBJ: Describe the electron configuration of a family or group of elements. TOP: The Periodic Table and Electron Configurations 141. The number of electrons present in the s orbitals in the outermost electron shell of the alkaline earth (Group IIA) metals is ____. a. one b. two c. three d. four e. five ANS: B OBJ: Describe the electron configuration of a family or group of elements. TOP: The Periodic Table and Electron Configurations 142. The number of electrons in p orbitals in the highest energy levels of the Group IVA elements is ____. a. one b. two c. three d. four e. six ANS: B OBJ: Describe the electron configuration of a family or group of elements. TOP: The Periodic Table and Electron Configurations 143. The number of electrons present in the outermost electron shell of the Group VA elements is: a. one b. two c. three d. four e. five
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ANS: E OBJ: Describe the electron configuration of a family or group of elements. TOP: The Periodic Table and Electron Configurations 144. The total number of electrons in s orbitals in a germanium atom (Z = 32) is ____. a. 18 b. 15 c. 8 d. 20 e. 6 ANS: C OBJ: Sum the number of s electrons in the ground state configuration of a given the element. TOP: The Periodic Table and Electron Configurations 145. The total number of electrons in p orbitals in a palladium atom (atomic number = 46) in its ground state is ____. a. 6 b. 12 c. 18 d. 24 e. 30 ANS: C OBJ: Sum the number of p electrons in the ground state configuration of a given the element. TOP: The Periodic Table and Electron Configurations 146. An element with the outermost electron configuration ns2np3 would be in Group a. VIIIA b. IIA c. IIIA d. VIIA e. VA ANS: E OBJ: Identify the family or group of elements with the given general configuration beyond the noble gas core. TOP: The Periodic Table and Electron Configurations 147. An element has the outermost electron configuration ns2np4. The element could be ____. a. Si b. O c. Br d. Ar e. Mn ANS: B REF: Identify the family or group of elements with the given general configuration beyond the noble gas core. TOP: The Periodic Table and Electron Configurations
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148. The group of elements with outermost electron configuration (n 1)d10ns2 is? a. IIA b. IIIB c. IB d. IIB e. IIIA ANS: D OBJ: Identify the family or group of elements with the given general configuration beyond the noble gas core. TOP: The Periodic Table and Electron Configurations 149. An element has the following outer electron configuration in its ground state, where n represents the highest occupied energy level: (n 1)d10ns2np4. Which of the elements listed below could it be? a. Si b. S c. Se d. Ge e. none of these ANS: C DIF: Harder Question OBJ: Identify the family or group of elements with the given general configuration beyond the noble gas core. TOP: The Periodic Table and Electron Configurations 150. An element has the following outer electron configuration in its ground state, where n represents the highest occupied energy level: (n 1)d10ns1. Which of the elements listed below could it be? a. K b. Ag c. Ge d. Ga e. Cd ANS: B DIF: Harder Question OBJ: Identify the family or group of elements with the given general configuration beyond the noble gas core. TOP: The Periodic Table and Electron Configurations 151. An element that has four electrons in its outer shell in its ground state is ____. a. Nb b. Mo c. Sn d. Zr e. S ANS: C OBJ: Determine the elements with only four electrons in their outmost shell. TOP: The Periodic Table and Electron Configurations
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152. The number of electrons present in the p orbitals in the outermost electron shell (major energy level, n) of the halogen atoms is ____. a. one b. two c. six d. seven e. five ANS: E OBJ: Determine the number of electrons in a specific orbital of an atom or family of atoms. TOP: The Periodic Table and Electron Configurations 153. Which of the following elements has an electron in a 5f subshell? a. Cm b. Ru c. Os d. Sm e. none of these ANS: A OBJ: Identify elements which have an electron in a specific subshell. TOP: The Periodic Table and Electron Configurations 154. The nucleus of a 209Bi nuclide contains a. 209 neutrons and 292 electrons. b. 83 protons and 209 neutrons. c. 209 protons and 126 electrons. d. 209 protons, 83 neutrons, and 209 electrons. e. 83 protons and 126 neutrons. ANS: E DIF: easy OBJ: Determine the number of each fundamental particle in a neutral atom given its mass number and symbol. TOP: Mass Number and Isotopes 155. How many electrons does the ion a. 78 b. 198 c. 82 d. 202 e. 118
have?
ANS: A DIF: easy OBJ: Determine the number of electrons in an ion given its atomic mass, atomic number, and symbol. TOP: Mass Number and Isotopes
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156. How many protons are there in the titanium-48 nuclide? a. 27 b. 70 c. 21 d. 22 e. 26 ANS: D DIF: easy OBJ: Determine the number of protons in an atom given its atomic mass and symbol. TOP: Mass Number and Isotopes 157. How many neutrons are there in 6 molecules of a. b. c. d. e.
?
240 120 7 444 204
ANS: A DIF: difficult OBJ: Determine the total number of neutrons in a given number of molecules. TOP: Mass Number and Isotopes 158. Which of the following has 62 neutrons, 46 protons, and 46 electrons? a. b. c. d. e. ANS: B DIF: easy OBJ: Identify the isotope given the number of neutrons, protons, and electrons. TOP: Mass Number and Isotopes 159. A photon of which type of electromagnetic radiation has the highest frequency? a. infrared (IR) b. ultraviolet (UV) c. yellow light d. green light e. gamma rays ANS: E DIF: easy OBJ: Identify the electromagnetic radiation with the highest or lowest frequency. TOP: Electromagnetic Radiation
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160. A light emitting diode (L.E.D.) emits photons with an energy of 3.000 10
19
J. What is the
energy per mole of photons emitted? a. b. c. d. e.
1.806 10 5 J/mol 4.981 10 46 J/mol 1.806 10 8 J/mol 3.000 10 19 J/mol 4.981 10 40 J/mol
ANS: A DIF: moderate OBJ: Calculate the energy of a mole of photons from its energy per photon. TOP: Electromagnetic Radiation 161. From the Bohr model of the hydrogen atom, we can conclude that the energy required to
excite an electron from n = 2 to n = 3 is ____ the energy required to excite an electron from n = 1 to 2. a. less than b. greater than c. equal to d. either equal to or less than e. either equal to or greater than ANS: A DIF: moderate OBJ: Relate the energy of a photon to the associated energy levels of an atom. TOP: Atomic Spectra and the Bohr Atom 162. Which element is found in the d-block of the periodic table? a. b. c. d. e.
Y Tb Na N none of the above
ANS: A DIF: easy OBJ: Identify the s, p, d, or f-block element. TOP: The Periodic Table and Electron Configurations 163. Which of the following atoms is paramagnetic in its ground state? a. b. c. d. e.
tantalum (Ta) nobelium (No) barium (Ba) cadmium (Cd) argon (Ar)
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ANS: A DIF: easy OBJ: Identify the paramagnetic or diamagnetic element. TOP: Paramagnetism and Diamagnetism 164. The element indium has two stable isotopes, indium-113 with an atomic mass of 112.9amu
and indium-115 with an atomic mass of 114.9amu. From the atomic weight found on the periodic table for indium, one can conclude that: a. Indium-113 has the highest percent natural abundance b. Indium-115 has the highest percent natural abundance c. Both isotopes have the same percent natural abundance d. There is an isotope of indium with an atomic mass of 114.8amu ANS: B OBJ: Identify the isotope with the greatest percent abundance based on atomic weight. TOP: The Atomic Weight Scale and Atomic Weights 165. A certain element consists of two stable isotopes. The first has a mass of 14.0031 amu and a
percent natural abundance of 99.63%. The second has a mass of 15.001 amu and a percent natural abundance of 0.37%. What is the atomic weight of the element? a. 13.95 amu b. 14.00 amu c. 14.01 amu d. 14.50 amu e. 19.50 amu ANS: C OBJ: Calculate the atomic weight given isotope percent abundance and isotopic masses. TOP: The Atomic Weight Scale and Atomic Weights 166. What is the identity of the transition element in the fourth row and group 6B? a. Mo b. Cr c. W d. Hf e. Zr ANS: B OBJ: Identify the element. TOP: The Periodic Table 167. What is the name of the symbol of the element that is in Group 3A and Period 5? a. Al b. In c. Nb d. Tl e. Y ANS: B OBJ: Identify the element. TOP: The Periodic Table 168. What is the name of the halogen that is in Period 4? a. bromine b. calcium c. iodine d. krypton
e. potassium
ANS: A OBJ: Identify the element. TOP: The Periodic Table
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169. What is the common name of the group that has as one of its members the element which
contains 35 protons in its nucleus? a. Alkali metals b. Alkaline earth metals c. Transition metals d. Halogens e. Noble gases ANS: D OBJ: Identify the element. TOP: The Periodic Table and Electron Configurations 170. How many protons, neutrons and electrons are there in: a. 3p+, 3no, 3eb. 3p+, 6no, 3ec. 6p+, 3no, 6ed. 6p+, 3no, 3ee. 3p+, 6no, 6eANS: A OBJ: Determine the number of each fundamental particle in an atom given its atomic mass and symbol. TOP: Structure of the Atom 171. What is the symbol for an ion of an element which has 12 protons and 10 electrons. a. Mg2+ b. Mg2c. Ne2+ d. Ne2e. Ti2+ ANS: A OBJ: Identify the ion given the number of protons and electrons. TOP: Structure of the Atom 172. Which of the following pairs have the same number of neutrons? a. and b. c. d. e.
and and and and
ANS: B OBJ: Identify isotopes with equal numbers of neutrons. TOP: Structure of the Atom 173. How many protons and electrons does the most stable ion for calcium have?
# protons a. 20p+ b. 22p+ c. 20p+ d. 20p+ e. 20p+
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ANS: C OBJ: Determine the number of each fundamental particle in a monatomic ion. TOP: Atomic Number 174. Place the following types of electromagnetic radiation in order of decreasing energy:
Ultraviolet radiowaves microwaves a. Radiowaves > microwaves > ultraviolet b. Ultraviolet > microwaves > radiowaves c. Radiowaves > ultraviolet > microwaves d. Ultraviolet > radiowaves > microwaves e. Microwaves > radiowaves > ultraviolet ANS: B OBJ: Rank the classes of electromagnetic radiation. TOP: Electromagnetic Radiation 175. It takes 513kJ to remove a mole of electrons from the atoms at the surface of a piece of metal.
How much energy does it take to remove a single electron from an atom at the surface of that metal? a. 3.09 x 1026 J b. 3.09 x 1029J c. 4.29 x 10-17 J d. 8.52 x 10-19J e. 8.52 x 10-22 J ANS: D OBJ: Convert the energy per mole of electrons to energy per electron. TOP: Atomic Spectra and the Bohr Atom 176. Which of the diagrams below shows the emission of the longest wavelength of light? a. b. c. d.
ANS: B OBJ: Identify the longest wavelength emission process. TOP: Atomic Spectra and the Bohr Atom 177. Calculate the energy for the transition of an electron from the n = 4 level to the n = 1 level of a
hydrogen atom. a. -2.178 x 10-18 J b. -1.361x10-19 J c. -5.445x10-19 J d. -2.042x10-18 J e. -3.165x10-19 J
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ANS: D OBJ: Calculate the energy of an electron transition. TOP: Atomic Spectra and the Bohr Atom 178. How many sublevels are contained in the second energy level (n=2) of a given atom? a. 0 b. 1 c. 2 d. 3 e. 4 ANS: C OBJ: Identify the number of sublevels for a given principal quantum number. TOP: The Quantum Mechanical Picture of the Atom 179. How many different values of ml are possible in the 4f sublevel? a. 1 b. 2 c. 3 d. 5
e. 7
ANS: E OBJ: Determine the values of the magnetic quantum numbers given the sublevel. TOP: The Quantum Mechanical Picture of the Atom 180. In which orbital below would an electron (on average) be closest to the nucleus? a. 2p b. 4s c. 2s d. 5d e. 3p ANS: C OBJ: Identify the orbital where electrons are closest to the nucleus. TOP: The Quantum Mechanical Picture of the Atom 181. What would be the wavelength of radiation emitted from a hydrogen atom when an electron
moves from the n = 4 to the n = 2 energy level? a. 486 nm b. 365 nm c. 760 nm
d. 219 nm
e. 197 nm
ANS: A OBJ: Calculate the energy of an electronic transition. TOP: Atomic Spectra and the Bohr Atom 182. Based on the shape and number of nodes in the picture of an orbital below, what are the
values for n and l ?
a. n = 1, l = 0
b. n = 2, l = 0
c. n = 3, l = 0
d. n = 2, l = 1
e. n = 3, l = 1
ANS: C OBJ: Identify the atomic orbital. TOP: Atomic Orbitals 183. The element that corresponds to the electron configuration 1s22s22p6 is: a. Sodium b. Magnesium c. Lithium d. Beryllium e. Neon ANS: E OBJ: Identify the element given the electron configuration. TOP: Electron Configurations Whitten 10e
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184. An element that has the valence electron configuration 6s26p6 belongs to which period and
group on the periodic table? a. Period 6 Group 2 b. Period 6 Group 6 c. Period 6 Group 8 d. Period 6 Group 16 e. Period 6 Group 18 ANS: E OBJ: Identify the element given the valence electron configuration. TOP: Electron Configurations 185. How many unpaired electrons are present in the ground state phosphorus atom? a. 0 b. 1 c. 2 d. 3 e. 4 ANS: D OBJ: Determine the number of unpaired electrons given the element. TOP: Electron Configurations SHORT ANSWER
Use the pictures below to answer questions 10 – 12: A.
B.
...
C.
...
1. Which of the pictures above depicts a diamagnetic substance, which would be slightly
repelled by a magnetic field? ANS: A OBJ: Identify the diamagnetic substance. TOP: Paramagnetism and Diamagnetism 2. Which of the pictures above depicts a ferromagnetic substance, which would be strongly
attracted to a magnetic field? ANS: B OBJ: Identify the ferromagnetic substance. TOP: Paramagnetism and Diamagnetism 3. Which of the pictures above depicts a paramagnetic substance, which would be attracted to a
magnetic field? ANS: C OBJ: Identify the paramagnetic substance. TOP: Paramagnetism and Diamagnetism Whitten 10e
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CONCEPTUAL 1. A nickel atom has 28 protons and a cobalt atom has 27. Yet, the atomic mass of Ni is 58.69 amu where Co = 58.93 amu. Explain how this is possible in terms of abundance of isotopes. OBJ: Explain the effect of isotopic abundance on atomic weight. TOP: Mass Number and Isotopes 2. A mass spectrometer produces a characteristic spectrum of positively charged pieces of a molecule. Explain how a mass spectrometer could be used to detect banned substances in an Olympic athlete's urine. OBJ: Explain how a mass spectrometer could be used to identify molecular substances. TOP: Mass Spectrometry and Isotopic Abundance 3. Why was Rutherford surprised by the results of his gold-foil experiment? How did his results change theories of atomic structure? What would happen if the nucleus were really as dense as previously thought? OBJ: Compare and contrast Rutherford's understanding of the atomic structure before and after his gold-foil experiment. TOP: Rutherford and the Nuclear Atom 4. Describe the light produced by a neon bulb in terms of emission spectra. OBJ: Explain the range of wavelengths of light produced in a neon light bulb in terms of atomic emission. TOP: The Quantum Mechanical Picture of the Atom | Electromagnetic Radiation 5. Explain how TV and radio waves can harmlessly pass through our bodies but other forms of electromagnetic radiation like X-rays and gamma rays are much more harmful. OBJ: Explain the connection between bond strength in molecules and the energy of light required to disrupt a bond. TOP: Electromagnetic Radiation | Atomic Bond Strength 6. Write the electron configuration for a hypothetical element with atomic number 118. How many new elements beyond #118 would have to be synthesized before we need the 7d orbitals? OBJ: Determine the electron configuration of an atom given its atomic number. | Determine the minimum atomic number of an element with an electron in a 7d orbital. TOP: Electron Configurations 7. Why do elements in Gp VIB and Gp IB (such as Cr and Cu) have unexpected electron configurations? OBJ: Guess the origin of anomalous (or unexpected) electron configurations. TOP: The Quantum Mechanical Picture of the Atom 8. How many possible emission lines could we expect from a sample of hydrogen gas with its electrons excited to the 6th level? OBJ: Predict the number of emission lines of an excited hydrogen atom. TOP: The Quantum Mechanical Picture of the Atom Whitten 10e
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Chapter 5—Chemical Periodicity MULTIPLE CHOICE 1. According to the periodic law the properties of elements repeat at regular intervals when the elements are arranged in order of a. their increasing atomic mass. b. their increasing atomic size. c. their increasing number of neutrons in the nucleus. d. their increasing number of isotopes. e. their increasing number of protons in the nucleus. ANS: E OBJ: Understand the periodic law. TOP: More About the Periodic Table 2. Which electrons have the greatest influence on the properties of elements? a. those electrons in s orbitals b. those electrons in d orbitals c. core electrons d. the outermost electrons e. none of these ANS: D OBJ: Understand the importance of the outermost electrons in chemistry. TOP: More About the Periodic Table 3. Of the following, which element does not match its designation? a. 38Sr / representative metal b. 49In / representative nonmetal c. 14Si / metalloid d. 42Mo / d-transition metal e. 90Th / f-transition metal ANS: B OBJ: Classify an element. TOP: More About the Periodic Table 4. Of the following, which periodic group(s) do not match their designation? a. d-transition metals / IIIB IIB b. representative metals / IA, IIA c. noble gases / VIIIB d. alkaline earth metals / IIA e. halogens / VIIA ANS: C OBJ: Match the family of elements with the group number(s). TOP: More About the Periodic Table
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5. ____ is a d-transition metal. a. Cr b. Ga c. Sn d. Sb e. Li ANS: A OBJ: Identify a d-transition metal. TOP: More About the Periodic Table 6. ____ is a noble gas. a. 22Ti b. 42Mo c. 81Tl d. 54Xe e. 92U ANS: D OBJ: Identify a noble gas. TOP: More About the Periodic Table 7. ____ is an actinide. a. 22Ti b. 42Mo c. 81Tl d. 36Kr e. 93Np ANS: E OBJ: Identify an actinide. TOP: More About the Periodic Table 8. Which one of the following is an inner transition (f-transition) element? a. Rb b. Ho c. Co d. Ru e. Bi ANS: B OBJ: Identify an inner transition element. TOP: More About the Periodic Table 9. Which of the following is not a representative element? a. Cl b. Sr c. Co d. K e. N ANS: C OBJ: Identify the element that is least representative of a family. TOP: More About the Periodic Table
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10. Choose the response that includes all of the listed elements that are d-transition elements, and no others. I. 22Ti II. 42Mo III. 81Tl IV. 36Kr V. 92U a. b. c. d. e.
I and II II and III III and IV IV and V I, III, and V
ANS: A OBJ: Identify d-transition metals. TOP: More About the Periodic Table 11. What would be the outer electron configuration of group VIA (O, S, Se, . . .)? a. ns2np6 b. ns2np2 c. ns2np4 d. np6 e. ns0np6 ANS: C OBJ: Determine the electron configuration beyond the noble gas core given the group number. TOP: More About the Periodic Table 12. What would be the outer electron configuration of group IIIB (Sc, Y, La . . .)? a. ns2nd2np0 b. nd1ns2 c. ns2(n 1)d1 d. ns1np3 e. (n 1)d1ns2 ANS: E OBJ: Determine the electron configuration beyond the noble gas core given the group number. TOP: More About the Periodic Table 13. What would be the outer electron configuration of alkaline earth metals? a. ns2np2 b. np2 c. ns0np2 d. nd2 e. ns2 ANS: E OBJ: Determine the electron configuration beyond the noble gas core given the group number. TOP: More About the Periodic Table
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14. Choose the term that best describes all members of this series of elements: Xe, Rn, He, Ne, Kr a. b. c. d. e.
metalloids noble gases alkaline earth metals alkali metals representative elements
ANS: B OBJ: Classify a group of elements. TOP: More About the Periodic Table 15. Which of the following statements is false? a. The effective nuclear charge experienced by an electron in an outer shell is less than the actual nuclear charge. b. Within a family (vertical group in the periodic table) of representative elements atomic radii increase from top to bottom. c. Electrons in inner shells screen, or shield, electrons in outer shells from the full effect of the nuclear charge. d. The atomic radii of representative elements decrease from left to right across a period (horizontal row in the periodic table). e. Transition elements have larger atomic radii than the preceding IA and IIA elements in the same period because transition elements have electrons in their d orbitals. ANS: E OBJ: Understand the term effective nuclear charge. | Understand the term shielding. | Understand the general relationship between atomic radii and nuclear charge. TOP: Atomic Radii 16. Which element has the largest atomic radius? a. Al b. Si c. P d. S e. Cl ANS: A OBJ: Identify the atom with the largest radius. TOP: Atomic Radii 17. Which element has the largest atomic radius? a. B b. Al c. Ga d. In e. Tl ANS: E OBJ: Identify the atom with the largest radius. TOP: Atomic Radii
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18. Which element has the largest atomic radius? a. At b. Pb c. As d. Sn e. Xe ANS: B OBJ: Identify the atom with the largest radius. TOP: Atomic Radii 19. Which element has the largest atomic radius? a. Ga b. In c. Ge d. P e. O ANS: B OBJ: Identify the atom with the largest radius. TOP: Atomic Radii 20. Which element has the largest atomic radius? a. 3Li b. 11Na c. 37Rb d. 9F e. 53I ANS: C OBJ: Identify the atom with the largest radius. TOP: Atomic Radii 21. Which element has the largest atomic radius? a. F b. Cl c. Sn d. Kr e. Se ANS: C OBJ: Identify the atom with the largest radius. TOP: Atomic Radii 22. Which element has the largest atomic radius? a. Ca b. Sr c. Cr d. P e. Na ANS: B OBJ: Identify the atom with the largest radius. TOP: Atomic Radii
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23. Which element has the largest atomic radius? a. 9F b. 16S c. 11Na d. 28Ni e. 37Rb ANS: E OBJ: Identify the atom with the largest radius. TOP: Atomic Radii 24. Which element has the smallest radius? a. Na b. Mg c. Al d. Si e. P ANS: E OBJ: Identify the atom with the smallest radius. TOP: Atomic Radii 25. Which element has the smallest radius? a. F b. Cl c. Br d. I e. At ANS: A OBJ: Identify the atom with the smallest radius. TOP: Atomic Radii 26. Which element has the smallest radius? a. Mo b. Au c. Bi d. In e. Te ANS: E OBJ: Identify the atom with the smallest radius. TOP: Atomic Radii 27. Which element has the smallest radius? a. K b. Na c. Rb d. Mg e. Cl ANS: E OBJ: Identify the atom with the smallest radius. TOP: Atomic Radii
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28. Arrange the following elements in order of increasing atomic radii. Sr, Rb, Sb, I, In a. b. c. d. e.
Rb < Sr < In < Sb < I I < Sb < In < Rb < Sr In < Sb < I < Sr < Rb Sb < I < In < Sr < Rb I < Sb < In < Sr < Rb
ANS: E OBJ: Arrange the atoms according to size (five atoms). TOP: Atomic Radii 29. Arrange the following elements in order of increasing atomic radii. K, Na, Mg, Cs, Cl a. b. c. d. e.
Na < Mg < Cl < K < Cs Cl < Mg < Na < K < Cs Cs < K < Cl < Mg < Na Cl < Mg < Cs < K < Na Cl < Mg < Na < Cs < K
ANS: B OBJ: Arrange the atoms according to size (five atoms). TOP: Atomic Radii 30. Arrange the following elements in order of decreasing atomic radii. Pb, P, Cl, F, Si a. b. c. d. e.
Cl > F > Pb > Si > P Pb > Si > P > F > Cl Pb > Si > P > Cl > F Pb > Cl > P > Si > F Pb > Cl > P > Si > F
ANS: C OBJ: Arrange the atoms according to size (five atoms). TOP: Atomic Radii 31. As we move across the periodic table from left to right, atoms become smaller due to a. increasing effective nuclear charge. b. the p orbitals being filled. c. electron-electron repulsions. d. shell size increases. e. none of these. ANS: A OBJ: Understand the effects of nuclear charge on atom size. TOP: Atomic Radii
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32. The minimum energy required to remove the most loosely held electron is a. first ionization energy. b. electron affinity c. potential energy d. kinetic energy e. electronegativity. ANS: A OBJ: Define first ionization energy. TOP: Ionization Energy 33. The first ionization energy of sulfur is less than that of phosphorus. A reasonable explanation for this fact involves a. the stability of the half-filled subshell in atomic sulfur. b. pairing of two electrons in one 3p orbital in sulfur atoms. c. the smaller size of sulfur atoms relative to phosphorus atoms. d. the ease with which phosphorus attains a noble gas electronic configuration. e. the higher electronegativity of sulfur relative to phosphorus. ANS: B OBJ: Understand the causes of differences between ionization energies. TOP: Ionization Energy 34. Which element has the lowest first ionization energy? a. F b. Cl c. Br d. I e. At ANS: E OBJ: Identify the atom with the lowest ionization energy. TOP: Ionization Energy 35. Which element has the lowest first ionization energy? a. Cs b. Rb c. Ca d. Ba e. Na ANS: A OBJ: Identify the atom with the lowest ionization energy. TOP: Ionization Energy 36. Which element has the lowest first ionization energy? a. F b. B c. O d. S e. Sr ANS: E OBJ: Identify the atom with the lowest ionization energy. TOP: Ionization Energy Whitten 10e
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37. Which element has the lowest first ionization energy? a. Be b. B c. C d. N e. O ANS: B DIF: Harder Question OBJ: Identify the atom with the lowest ionization energy. TOP: Ionization Energy 38. Which element has the highest first ionization energy? a. B b. Al c. Ga d. In e. Tl ANS: A OBJ: Identify the atom with the highest ionization energy. TOP: Ionization Energy 39. Which element has the highest first ionization energy? a. Sn b. Cd c. As d. Tc e. Cl ANS: E OBJ: Identify the atom with the highest ionization energy. TOP: Ionization Energy 40. Which element has the highest first ionization energy? a. Li b. Cs c. Cl d. I e. Ar ANS: E OBJ: Identify the atom with the highest ionization energy. TOP: Ionization Energy 41. Which element has the highest first ionization energy? a. Be b. B c. C d. N e. O ANS: D OBJ: Identify the atom with the highest ionization energy. TOP: Ionization Energy Whitten 10e
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42. Arrange the following elements in order of increasing first ionization energy. Mg, Al, Si, P, S a. b. c. d. e.
Al < Mg < Si < S < P Mg < Al < Si < P < S Al < Mg < Si < P < S Mg < Al < Si < S < P Al < Mg < P < Si < S
ANS: A DIF: Harder Question OBJ: Arrange the atoms according to ionization energy (five atoms). TOP: Ionization Energy 43. Arrange the following elements in order of decreasing first ionization energy. Rb, In, Sn, Sb, As a. b. c. d. e.
Sb > Sn > In > As > Rb As > In > Sn > Sb > Rb Rb > As > Sb > Sn > In As > Sb > Sn > In > Rb As > Sn > Sb > In > Rb
ANS: D OBJ: Arrange the atoms according to ionization energy (five atoms). TOP: Ionization Energy 44. Arrange the following elements in order of decreasing first ionization energy. Be, Ca, Cs, Mg, K a. b. c. d. e.
Mg > Be > Ca > K > Cs Be > Mg > Ca > K > Cs Cs > K > Ca > Be > Mg Ca > Mg > Be > Cs > K Ca > Mg > Be > K > Cs
ANS: B OBJ: Arrange the atoms according to ionization energy (five atoms). TOP: Ionization Energy 45. Arrange the following elements in order of decreasing first ionization energy. F, Be, O, N, C a. b. c. d. e.
F > O > N > C > Be Be > C > O > N > F F > N > O > C > Be O > F > N > Be > C Be > C > N > O > F
ANS: C DIF: Harder Question OBJ: Arrange the atoms according to ionization energy (five atoms). TOP: Ionization Energy
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46. Which equation below depicts the reaction from which the first ionization energy would be determined? a. Ca(g) Ca+(g) + e b. Ca(s) Ca+(g) + e c. Ca(s) + e Ca-(g) d. Ca(g) Ca2+ + e e. None of these ANS: A OBJ: Identify a chemical equation representing the first ionization energy of an atom. TOP: Ionization Energy 47. The amount of energy absorbed in the process in which an electron is added to a neutral gaseous atom is defined as ____. a. shielding effect b. electronegativity c. electron affinity d. first ionization energy e. standard reduction potential ANS: C OBJ: Know the definition of electron affinity. TOP: Electron Affinity 48. Which of the following elements has the most negative electron affinity? a. Si b. P c. S d. Se e. Te ANS: C OBJ: Identify the atom with the most negative electron affinity. TOP: Electron Affinity 49. Which of the following elements has the most negative electron affinity? a. As b. Al c. K d. Se e. Sn ANS: D OBJ: Identify the atom with the most negative electron affinity. TOP: Electron Affinity 50. The general electron configuration for the element group that would have the largest negative value for the electron affinity for its atoms is ____? a. ns2np6 b. ns2np4 c. ns1 d. ns2np5 e. ns2np3
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ANS: D OBJ: Determine the electron configuration beyond the noble gas core for the group of elements with the most negative electron affinity. TOP: Electron Affinity 51. Arrange the following elements in order of increasing values of electron affinity, i.e., from most negative to least negative. (Note: None of these elements is an exception to the general trends of electron affinities.) Cl, Se, S, Cs, Rb, Te a. b. c. d. e.
Cl < S < Se < Rb < Te < Cs Cl > Te > Se > S > Rb > Cs Cl > Se > S > Te > Rb > Cs Cl < S < Se < Te < Cs < Rb Cl < S < Se < Te < Rb < Cs
ANS: E OBJ: Arrange the atoms according to electron affinities (five atoms). TOP: Electron Affinity 52. Which of the following statements about ionization energy and electron affinity is true? a. Elements with very high ionization energies usually have very negative electron affinities. b. IE1 and EA are equal in value but with the sign reversed. c. It is very easy to measure both IE and EA values. d. Elements with low IE, as well as very negative EA, tend to form cations easily. e. All of these statements are true. ANS: A OBJ: Understand both electron affinity and ionization energy. TOP: Electron Affinity 53. Which one of the following species is not isoelectronic with neon? a. Mg2+ b. Na+ c. O2 d. Si2+ e. Al3+ ANS: D OBJ: Determine all atoms or ions which are isoelectronic. TOP: Ionic Radii 54. Which one of the following pairs contains isoelectronic species? a. Na / Na+ b. S / Se c. S2 / Se2 d. F2 / Cl2 e. Na+ / O2 ANS: E OBJ: Determine atoms or ion pair which are isoelectronic. TOP: Ionic Radii
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55. Which of the following ions is not isoelectronic with the others? a. I b. Sb3+ c. Te2 d. Ba2+ e. Cs+ ANS: B OBJ: Determine all atoms or ions which are isoelectronic. TOP: Ionic Radii 56. Which of the following ions is not isoelectronic with a noble gas? a. Mg2+ b. P2 c. Cs+ d. Se2 e. Ba2+ ANS: B OBJ: Determine all atoms or ions which are isoelectronic. TOP: Ionic Radii 57. Which ion has the largest radius? a. O2 b. S2 c. Se2 d. Te2 e. Po2 ANS: E OBJ: Identify the ion with the largest radius. TOP: Ionic Radii 58. Which ion has the largest radius? a. F b. Cl c. Br d. I e. At ANS: E OBJ: Identify the ion with the largest radius. TOP: Ionic Radii 59. Which ion has the largest radius? a. Li+ b. Na+ c. Be2+ d. Mg2+ e. Al3+ ANS: B OBJ: Identify the ion with the largest radius. TOP: Ionic Radii Whitten 10e
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60. Simple positively charged ions are always ____ than the neutral atoms from which they are formed. a. smaller b. larger c. isoelectronic d. the same size e. more anionic ANS: A OBJ: Understand the relationship between the ionic radii and atomic radius of an atom. TOP: Ionic Radii 61. Which ion has the smallest radius? a. F b. Cl c. Br d. I e. At ANS: A OBJ: Identify the ion with the smallest radius. TOP: Ionic Radii 62. Which ion has the smallest radius? a. O2 b. S2 c. Se2 d. Te2 e. Po2 ANS: A OBJ: Identify the ion with the smallest radius. TOP: Ionic Radii 63. Which ion has the smallest radius? a. As3 b. Se2 c. Br d. Rb+ e. Sr2+ ANS: E OBJ: Identify the ion with the smallest radius. TOP: Ionic Radii 64. Which ion has the smallest radius? a. K+ b. Cs+ c. Sr2+ d. Ba2+ e. Tl3+ ANS: E DIF: Harder Question OBJ: Identify the ion with the smallest radius. TOP: Ionic Radii Whitten 10e
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65. Which ion or atom has the largest radius? a. S b. S2 c. Se d. Se2 e. Br ANS: D OBJ: Identify the ion or atom with the largest radius. TOP: Ionic Radii 66. Which ion or atom has the largest radius? a. Sr2+ b. Rb+ c. Kr d. Br e. Se2 ANS: E OBJ: Identify the ion or atom with the largest radius. TOP: Ionic Radii 67. Arrange the following set of ions in order of increasing ionic radii. Ca2+, Cl, K+, P3, S2 a. b. c. d. e.
Ca2+ < K+ < P3 < S2 < Cl Ca2+ < K+ < Cl < S2 < P3 K+ < Cl < Ca2+ < S2 < P3 Cl < S2 < P3 < Ca2+ < K+ P3 < S2 < Cl < K+ < Ca2+
ANS: B OBJ: Arrange the ions according to size (five ions). TOP: Ionic Radii 68. Arrange the following set of ions in order of decreasing ionic radii. Al3+, Ga3+, Ca2+, Rb+, K+ a. b. c. d. e.
Rb+ > Ga3+ > Ca2+ > K+ > Al3+ Rb+ > K+ > Ca2+ > Al3+ > Ga3+ Ga3+ > Al3+ > Ca2+ > Rb+ > K+ Rb+ > Ca2+ > K+ > Ga3+ > Al3+ Rb+ > K+ > Ca2+ > Ga3+ > Al3+
ANS: E OBJ: Arrange the ions according to size (five ions). TOP: Ionic Radii 69. Which of the lists of increasing ionic radii is not correct? a. Cl < Br < I b. Al3+ < Mg2+ < Na+ c. Ca2+ < Sr2+ < Ba2+ d. S2 < Cl < K+ e. Na+ < O2 < N3 Whitten 10e
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ANS: D OBJ: Find the ions not arranged according to size (three ions). TOP: Ionic Radii 70. Which of these comparisons according to radius is (are) correct? I. Na+ > Mg2+ II. In3+ > Sr2+ III. Cl > K+ IV. Cl > K a. b. c. d. e.
I and II II and IV I and III II and III III and IV
ANS: C OBJ: Identify the correct atom or ion size comparisons (two atoms or ions). TOP: Ionic Radii 71. A property that measures the ability of an atom to attract electrons in a chemical bond is a. binding energy. b. mass defect. c. electron affinity. d. ionization energy. e. electronegativity. ANS: E OBJ: Define electronegativity. TOP: Electronegativity 72. Which element has the lowest electronegativity? a. H b. Li c. Na d. K e. Cs ANS: E OBJ: Identify the atom with the lowest electronegativity. TOP: Electronegativity 73. Which element has the lowest electronegativity? a. Mg b. Na c. Rb d. Y e. Sc ANS: C OBJ: Identify the atom with the lowest electronegativity. TOP: Electronegativity
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74. Which element has the lowest electronegativity? a. K b. Ca c. Ga d. Ge e. As ANS: A OBJ: Identify the atom with the lowest electronegativity. TOP: Electronegativity 75. Which element has the lowest electronegativity? a. S b. Sc c. Sr d. Se e. Si ANS: C OBJ: Identify the atom with the lowest electronegativity. TOP: Electronegativity 76. Which element has the highest electronegativity? a. C b. Si c. Ge d. Sn e. Pb ANS: A OBJ: Identify the atom with the highest electronegativity. TOP: Electronegativity 77. Which element has the highest electronegativity? a. 3Li b. 7N c. 19K d. 33As e. 56Ba ANS: B OBJ: Identify the atom with the highest electronegativity. TOP: Electronegativity 78. Which element has the highest electronegativity? a. B b. Ge c. Ca d. O e. At ANS: D OBJ: Identify the atom with the highest electronegativity. TOP: Electronegativity
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79. Which element has the highest electronegativity? a. N b. Si c. As d. P e. C ANS: A OBJ: Identify the atom with the highest electronegativity. TOP: Electronegativity 80. Arrange the following elements in order of increasing electronegativities. Mg, Ra, P, Cl, Al a. b. c. d. e.
Mg < Ra < P < Al < Cl Ra < Mg < Al < P < Cl Mg < Ra < P < Cl <Al Al < P < Cl < Mg < Ra Al < P < Cl < Ra < Mg
ANS: B OBJ: Arrange the atoms according to electronegativities (five atoms). TOP: Electronegativity 81. Arrange the following elements in order of decreasing electronegativities. Al, Cs, Mg, Na, P a. b. c. d. e.
P > Al > Mg > Na > Cs Cs > Na > Mg > Al > P Al > Mg > Na > Cs > P P > Al > Mg > Cs > Na P > Cs > Na > Mg > Al
ANS: A OBJ: Arrange the atoms according to electronegativities (five atoms). TOP: Electronegativity 82. Which comparison of electronegativities is not correct? a. Br > Se b. K > Mg c. O > S d. N > Be e. I > Ba ANS: B OBJ: Identify the incorrect electronegativity comparison (two atoms). TOP: Electronegativity 83. Which comparison of electronegativities is not correct? a. Ge > Ga b. Ba > Cs c. O > N d. F > Cl e. B > C
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ANS: E OBJ: Identify the incorrect electronegativity comparison (two atoms). TOP: Electronegativity 84. Which of these elements has the greatest attraction for electrons in a covalent bond? a. Ge b. As c. Se d. Br e. Kr ANS: D OBJ: Identify the atom with the highest electronegativity. TOP: Electronegativity 85. Which of the following pairs of elements would be expected to form an ionic compound? a. S / F b. H / C c. Rb / Cl d. As / Br e. C / I ANS: C OBJ: Identify the atom pair most likely to form an ionic compound. TOP: Electronegativity 86. Which pair of elements below would be least likely to form an ionic bond between them? a. Na / S b. C / N c. Al / F d. Mg / Br e. Cs / O ANS: B OBJ: Identify the atom pair most likely to form a covalent compound. TOP: Electronegativity 87. Chlorine is most likely to form an ionic compound with ____. a. F b. O c. C d. N e. Li ANS: E OBJ: Identify the atom pair most likely to form an ionic compound. TOP: Electronegativity 88. Iodine is most likely to form an ionic compound with ____. a. B b. Si c. Cl d. N e. Mg
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ANS: E OBJ: Identify the atom pair most likely to form an ionic compound. TOP: Electronegativity 89. Which one of the following reactions does not produce H2(g)? a. electrolysis of H2O b. zinc with HCl(aq) c. combustion of ethane, C2H6 d. iron with steam e. steam cracking of hydrocarbons ANS: C OBJ: Recognize the reactions that produce hydrogen. TOP: Hydrogen and the Hydrides 90. Which of the following statements about hydrogen is false? a. Hydrogen occurs as a diatomic molecule. b. Hydrogen can be produced by the reaction of an active metal and HCl(aq). c. NH3, the binary hydride of nitrogen, is called ammonia. d. Hydrogen forms only molecular compounds. e. Metal hydrides are basic. ANS: D OBJ: Know the qualitative chemical facts about hydrogen. TOP: Hydrogen and the Hydrides 91. Which pair of gases is the product of the "water gas reaction"? a. H2O + H2 b. CO + H2O c. O2 + H2O d. CO + H2 e. H2 + O2 ANS: D OBJ: Know the products of the water gas reaction. TOP: Hydrogen and the Hydrides 92. Which one of the following reactions is the "water gas" reaction? a. C(s) + H O(g) CO(g) + H (g) 2
2
b. 2CH (g) + 3O (g) 2CO(g) + 4H2O(g) 4 2 c. CH4(g) C(s) + 2H2(g) d. 2Na(s) + 2H2O e. C4H10(g)
2NaOH(aq) + H2(g) 2C2H2(g) + 3H2(g)
ANS: A OBJ: Know the chemical equation for the water gas reaction. TOP: Hydrogen and the Hydrides
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93. Which one of the following (pure) compounds of hydrogen is ionic? a. HF b. HCl c. NaH d. H2O e. H2Se ANS: C OBJ: Identify the ionic compound. TOP: Hydrogen and the Hydrides 94. Which one of the following is an ionic hydride? a. CH4 b. H2Se c. AsH3 d. BaH2 e. B2H6 ANS: D OBJ: Identify the ionic compound. TOP: Hydrogen and the Hydrides 95. Which of the following responses lists only the molecular hydrides? I. LiH II. B2H6 III. GeH4 IV. HCl V. BaH2 a. b. c. d. e.
I I, V II, III II, III, IV I, II, V
ANS: D OBJ: Identify the covalent (molecular) hydrides. TOP: Hydrogen and the Hydrides 96. Which one of the following is a molecular hydride? a. RbH b. SrH2 c. KH d. PH3 e. MgH2 ANS: D OBJ: Identify the covalent (molecular) hydride. TOP: Hydrogen and the Hydrides
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97. Which of the following is incorrectly classified? a. KH / ionic hydride b. CH4 / ionic hydride c. HI / molecular hydride d. CsH / ionic hydride e. H2S / molecular hydride ANS: B DIF: Harder Question OBJ: Identify the incorrect compound classification. TOP: Hydrogen and the Hydrides 98. Which response includes all the elements below whose compounds with hydrogen would be expected to be molecular hydrides, and no others? Br, K, P, B a. b. c. d. e.
K, B Br, P K, Br Br, P, B Br
ANS: D OBJ: Identify the elements which produce covalent (molecular) hydrides. TOP: Hydrogen and the Hydrides 99. Which one of the following hydrides is basic? a. H2Te b. B2H6 c. CaH2 d. HI e. CH4 ANS: C OBJ: Classify a hydride as basic, acidic, or neutral. TOP: Hydrogen and the Hydrides 100. Which one of the following hydrides is not acidic? a. HF b. HCl c. H2S d. CaH2 e. H2Se ANS: D OBJ: Classify a hydride as basic, acidic, or neutral. TOP: Hydrogen and the Hydrides 101. What would be the general balanced equation for the reaction of the ionic hydride MH2 with excess water? a. MH2(s) + H2O MOH(aq) + H2(g) b. MH2(s) + H2O MO(s) + 2H2(g) c. MH2(s) + H2O MH2(s) + H2O(g) d. MH2(s) + 2H2O M(OH)2(aq) + 2H2(g) e. MH2(s) + 3H2O MO(s) + 4H2(g) + O2(g) Whitten 10e
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ANS: D DIF: Harder Question OBJ: Know the products of reaction between an ionic hydride and water. TOP: Hydrogen and the Hydrides 102. Write the balanced formula unit equation for the reaction of nitrogen with hydrogen at high temperature and pressure. What is the sum of the coefficients? (Do not forget coefficients of one.) Use the smallest whole number coefficients. a. 6 b. 7 c. 8 d. 4 e. 5 ANS: A OBJ: Write a balanced chemical equation for the reaction of a nonmetal with hydrogen. | Sum the coefficients. TOP: Hydrogen and the Hydrides 103. Write the balanced formula unit equation for the reaction of magnesium with hydrogen at high temperature. What is the sum of the coefficients? (Do not forget coefficients of one.) Use the smallest whole number coefficients. a. 5 b. 6 c. 3 d. 4 e. none of these ANS: C OBJ: Write a balanced chemical equation for the reaction of a metal with hydrogen. | Sum the coefficients. TOP: Hydrogen and the Hydrides 104. Write the balanced formula unit equation for the reaction of magnesium with hydrochloric acid. What is the sum of the coefficients? (Do not forget coefficients of one.) Use the smallest whole number coefficients. a. 5 b. 6 c. 3 d. 4 e. none of these ANS: A OBJ: Write a balanced chemical equation for the reaction of a metal with an acid. | Sum the coefficients. TOP: Hydrogen and the Hydrides 105. Write the balanced formula unit equation for the reaction of sodium hydride with water. What is the sum of the coefficients in the balanced equation? Use the smallest whole numbers possible. (Do not forget coefficients of one.) a. three b. four c. five d. six e. eight Whitten 10e
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ANS: B OBJ: Write a balanced chemical equation for the reaction of an ionic hydride with water. | Sum the coefficients. TOP: Hydrogen and the Hydrides 106. Magnesium hydride is ____. a. basic b. neutral c. acidic d. inert e. non-reactive with water ANS: A OBJ: Classify a hydride as basic, acidic, or neutral. TOP: Hydrogen and the Hydrides 107. Oxygen was discovered by Priestley in 1774 when he observed the ____. a. electrolysis of water b. thermal decomposition of mercury(II) oxide, HgO c. reaction of sulfuric acid, H2SO4, with sodium d. results of fractional distillation of air e. the thermal decomposition of potassium chlorate, KClO3 ANS: B OBJ: Know how Priestley discovered oxygen. TOP: Oxygen and the Oxides 108. Which of the following statements about oxygen is false? a. The most common form of oxygen is a diatomic molecule. b. Ozone is an allotrope of oxygen. c. Oxygen forms basic metal oxides. d. Oxygen forms binary compounds with nonmetals called acid anhydrides. e. Oxygen always forms 2 ions with metals. ANS: E OBJ: Know the qualitative chemical facts about oxygen. TOP: Oxygen and the Oxides 109. Which one of the following will not react with oxygen to form a peroxide? a. Be b. Ca c. Sr d. Ba e. all of these form peroxides ANS: A OBJ: Identify the element which will not form a peroxide. TOP: Oxygen and the Oxides
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110. Which statement does not accurately describe ozone? a. Its molecules are angular. b. Its density is about 1 times that of O2. c. Its two oxygenoxygen bond lengths are 1.23 Å and 1.48 Å. d. It is unstable. e. It is a very strong oxidizing agent. ANS: C OBJ: Know the structure, physical properties, and reactivity of ozone. TOP: Oxygen and the Oxides 111. Which of the following anions represents a peroxide? a. O b. O2 c. O2 d. O22 e. O3 ANS: D OBJ: Identify the peroxide ion. TOP: Oxygen and the Oxides 112. Which one of the following compounds is a superoxide? a. Na2O2 b. SrO c. KO2 d. Li2O e. Cl2O7 ANS: C OBJ: Identify the superoxide. TOP: Oxygen and the Oxides 113. What is the principal product of the reaction of sodium with oxygen? a. NaO b. Na2O c. Na2O2 d. NaO2 e. Na2O3 ANS: C OBJ: Identify the principal product of reaction of sodium and oxygen. TOP: Oxygen and the Oxides 114. Which one of the following does not represent correctly the major product formed by the reaction of an alkali metal with oxygen at ordinary temperatures and pressures? a. Li2O2 b. Na2O2 c. KO2 d. RbO2 e. CsO2
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ANS: A OBJ: Identify the incorrect principal product of an alkali metal and oxygen reaction. TOP: Oxygen and the Oxides 115. Which of the following statements about binary oxides is false? a. Basic oxides are molecular. b. Some oxides like BeO are amphoteric. c. Nonmetal oxides are usually acidic. d. Metal oxides are usually basic. e. Acid anhydrides are molecular. ANS: A OBJ: Know the qualitative chemical facts about binary oxides. TOP: Oxygen and the Oxides 116. Which response includes all the oxides below that are ionic and none that are molecular? I. Na2O II. MgO III. As2O5 IV. SO3 a. b. c. d. e.
II and IV I, II, and III I and II III and IV II and III
ANS: C OBJ: Identify the ionic oxides. TOP: Oxygen and the Oxides 117. Which response contains all the basic oxides listed below and no others? I. NO II. CaO III. Li2O IV. SO2 V. P4O10 a. b. c. d. e.
I and IV II and IV I, III, and IV IV and V II and III
ANS: E OBJ: Identify the basic oxides. TOP: Oxygen and the Oxides 118. Which of the following oxides is a basic anhydride? a. N2O b. P4O6 c. CaO d. OF2 e. H2O Whitten 10e
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ANS: C OBJ: Identify the basic anhydride. TOP: Oxygen and the Oxides 119. Which response includes all of the following oxides that are acid anhydrides? I. CO2 II. CaO III. ClO2 IV. Tl2O3 a. b. c. d. e.
I and III II and IV I and IV II, III, and IV I
ANS: A OBJ: Identify the acid anhydrides. TOP: Oxygen and the Oxides 120. Which of the following oxides does not give an acidic solution when dissolved in water? a. SO2 b. CO2 c. N2O5 d. P4O10 e. Na2O ANS: E OBJ: Identify the basic anhydride. TOP: Oxygen and the Oxides 121. An amphoteric compound exhibits a. acidic properties. b. acidic and basic properties. c. metallic properties. d. basic properties. e. ionic properties. ANS: B OBJ: Define amphoteric. TOP: Oxygen and the Oxides 122. Which one of the following oxides is amphoteric? a. Li2O b. BeO c. CO2 d. P4O6 e. Cl2O ANS: B OBJ: Identify the amphoteric oxide. TOP: Oxygen and the Oxides
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123. Which of the following oxides is not amphoteric? a. Al2O3 b. BeO c. SnO2 d. Br2O7 e. PbO2 ANS: D OBJ: Identify the non-amphoteric oxide. TOP: Oxygen and the Oxides 124. One of the following oxides is insoluble in water. Which one? a. CO2 b. N2O5 c. SO2 d. SiO2 e. SO3 ANS: D DIF: Harder Question OBJ: Identify the aqueous insoluble compound. TOP: Oxygen and the Oxides 125. Arrange the following in order of increasing ionic character (most ionic at right). BaO, SiO2, SO2 a. b. c. d. e.
BaO < SiO2 < SO2 SO2 < BaO < SiO2 SiO2 < SO2 < BaO BaO < SO2 < SiO2 SO2 < SiO2 < BaO
ANS: E OBJ: Order the compounds with respect to ionic character (three compounds). TOP: Oxygen and the Oxides 126. Arrange the following in order of decreasing basicity. MgO, Cs2O, Cl2O7, SnO2, P4O10 a. b. c. d. e.
Cs2O > MgO > SnO2 > P4O10 > Cl2O7 MgO > Cs2O > P4O10 > SnO2 > Cl2O7 Cs2O > SnO2 > MgO > P4O10 > Cl2O7 MgO > Cs2O > SnO2 > P4O10 > Cl2O7 Cl2O7 > P4O10 > SnO2 > Cs2O > MgO
ANS: A OBJ: Order the compounds with respect to basic character (five compounds). TOP: Oxygen and the Oxides
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127. Arrange the following in order of increasing acidic character (most acidic at the right). Al2O3, Na2O, N2O5 a. b. c. d. e.
Al2O3 < Na2O < N2O5 N2O5 < Al2O3 < Na2O Al2O3 < N2O5 < Na2O Na2O < Al2O3 < N2O5 Na2O < N2O5 < Al2O3
ANS: D OBJ: Order the compounds with respect to acidic character (three compounds). TOP: Oxygen and the Oxides 128. Which one of the following compounds would be expected to react with oxygen at elevated temperatures to produce both an acidic oxide and a basic oxide? a. CH4 b. CS2 c. CaS d. NO e. H2S ANS: C OBJ: Identify the compound that combines with oxygen to form acidic and basic oxides. TOP: Oxygen and the Oxides 129. The acid formed by dissolving Cl2O7 in water is ____. a. HClO b. HClO2 c. HClO3 d. HClO4 e. HCl ANS: D OBJ: Identify the acid produced from dissolution of a molecular oxide. TOP: Oxygen and the Oxides 130. Write the balanced formula unit equation for the reaction of sodium with oxygen (use the major product). What is the sum of the coefficients? a. 2 b. 7 c. 3 d. 4 e. 5 ANS: D OBJ: Write a balanced chemical equation for the reaction of a metal with oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides
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131. Write the balanced formula unit equation for the reaction of rubidium, Rb, with oxygen (use the major product). What is the sum of the coefficients? a. 3 b. 7 c. 8 d. 4 e. 5 ANS: A OBJ: Write a balanced chemical equation for the reaction of a metal with oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides 132. Write the balanced formula unit equation for the reaction of barium with a limited amount (low pressure) of oxygen. What is the sum of the coefficients? a. 2 b. 6 c. 3 d. 4 e. 5 ANS: E OBJ: Write a balanced chemical equation for the reaction of a metal with limited oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides 133. Write the balanced formula unit equation for the reaction of barium with an excess (high pressure) of oxygen. What is the sum of the coefficients? a. 2 b. 8 c. 3 d. 4 e. 5 ANS: C OBJ: Write a balanced chemical equation for the reaction of a metal with excess oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides 134. Write the balanced formula unit equation for the reaction of copper with excess O2 at elevated temperatures. What is the sum of the coefficients? a. 6 b. 8 c. 3 d. 4 e. 5 ANS: E OBJ: Write a balanced chemical equation for the reaction of a metal with excess oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides
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135. Which of the following metal oxides would not be expected to form under conditions of limited oxygen? a. FeO b. PbO c. Cu2O d. CrO3 e. SnO ANS: D OBJ: Identify the oxide that is unlikely to be formed in limited oxygen. TOP: Oxygen and the Oxides 136. Write the balanced formula unit equation for the reaction of arsenic, As4, heated with an excess of oxygen (The molecular formula for the product is the same as the empirical formula). What is the sum of the coefficients? a. 7 b. 8 c. 3 d. 4 e. 5 ANS: B OBJ: Write a balanced chemical equation for the reaction of a nonmetal with excess oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides 137. Write the balanced formula unit equation for the reaction of barium oxide with water. What is the sum of the coefficients? a. 6 b. 8 c. 3 d. 4 e. 5 ANS: C OBJ: Write a balanced chemical equation for the reaction of a metal oxide with water. | Sum the coefficients. TOP: Oxygen and the Oxides 138. Write the balanced formula unit equation for the reaction of lithium oxide with water. What is the sum of the coefficients? a. 2 b. 6 c. 3 d. 4 e. 5 ANS: D OBJ: Write a balanced chemical equation for the reaction of a metal oxide with water. | Sum the coefficients. TOP: Oxygen and the Oxides
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139. Lithium hydroxide is sometimes used to remove carbon dioxide from the atmosphere of disabled submarines. Write the balanced formula unit equation for this reaction if the products are lithium carbonate and water. What is the sum of the coefficients? a. 7 b. 6 c. 5 d. 4 e. 8 ANS: C OBJ: Write a balanced chemical equation given the reactants and products. | Sum the coefficients. TOP: Oxygen and the Oxides 140. Write the balanced formula unit equation for the reaction of dichlorine heptoxide with water. What is the sum of the coefficients? a. 7 b. 8 c. 3 d. 4 e. 5 ANS: D OBJ: Write a balanced chemical equation for the reaction of a nonmetal oxide with water. | Sum the coefficients. TOP: Oxygen and the Oxides 141. Write the balanced formula unit equation for the reaction of dinitrogen pentoxide with water. What is the sum of the coefficients? a. 6 b. 8 c. 3 d. 4 e. 5 ANS: D OBJ: Write a balanced chemical equation for the reaction of a nonmetal oxide with water. | Sum the coefficients. TOP: Oxygen and the Oxides 142. Octane, C8H18, is a major component of gasoline. Write the balanced formula unit equation for the reaction of the complete combustion of octane. What is the sum of the coefficients? a. 49 b. 73 c. 17 d. 61 e. 30 ANS: D OBJ: Write a balanced chemical equation for the combustion of a hydrocarbon in excess oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides
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143. Write the balanced formula unit equation for the reaction of the complete combustion of ethane, C2H6. What is the sum of the coefficients? a. 19 b. 16 c. 17 d. 4 e. 5 ANS: A OBJ: Write a balanced chemical equation for the combustion of a hydrocarbon in excess oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides 144. Write the balanced formula unit equation for the reaction of the complete combustion of pentane, C5H12. What is the sum of the coefficients? a. 16 b. 19 c. 20 d. 21 e. 22 ANS: C OBJ: Write a balanced chemical equation for the combustion of a hydrocarbon in excess oxygen. | Sum the coefficients. TOP: Oxygen and the Oxides 145. Write the balanced formula unit equation for the reaction of nitrogen oxide with oxygen. What is the sum of the coefficients? a. 3 b. 6 c. 8 d. 4 e. 5 ANS: E OBJ: Write a balanced chemical equation for the combustion of a nonmetal oxide. | Sum the coefficients. TOP: Oxygen and the Oxides 146. Most of the air pollution resulting from combustion of (non-lead-containing) fossil fuels is due to oxides of ____. a. N, P, and S b. C, N, and S c. C, P, and S d. P and C e. P, C, and N ANS: B OBJ: Know the oxides that result from the combustion of fossil fuels. TOP: Oxygen and the Oxides
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147. Combustion of fossil fuels and the roasting of metal ores often both produce oxides of a. P b. N c. S d. Si e. C ANS: C OBJ: Know the oxides that result from the combustion of fossil fuels and roasting of ores. TOP: Oxygen and the Oxides 148. The brownish color of photochemical smog is due to ____. a. CO b. NO2 c. NO d. SO2 e. SO3 ANS: B OBJ: Know the components of smog. TOP: Oxygen and the Oxides 149. Combustion of fossil fuels contaminated with sulfur leads to what phenomena? a. greenhouse effect b. global warming c. ozone destruction d. photochemical smog e. acid rain ANS: E OBJ: Know the effect of sulfur contamination in fossil fuels. TOP: Oxygen and the Oxides 150. The two acids that are major contributors to "acid rain" are ____. a. H2CO3 and HNO3 b. H2SO4 and H3PO4 c. H2CO3 and H2SO4 d. H2SO4 and HNO3 e. H3PO4 and HNO3 ANS: D OBJ: Identify the acids which contribute to acid rain. TOP: Oxygen and the Oxides 2
6
151. The ground-state valence-shell configuration of a particular atom is 4s 4p . This valence-shell
electron configuration identifies the atom as a. b. c. d. e.
a noble gas. a d-transition element. an f-transition element. an s-block representative element. a p-block representative element.
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ANS: A DIF: easy OBJ: Classify a group of elements based on thier valence shell electron configuration. TOP: More About the Periodic Table 152. An element that has the same ground state valence-shell electron configuration as silicon is a. b. c. d. e.
lead. argon. lithium. magnesium. gallium.
ANS: A DIF: easy OBJ: Determine the configuration of an atom using the period and group numbers. TOP: electronic structure of atoms 153. Rank the following atoms in order of the largest to smallest atomic radius: Se, K, As, Rb. a. b. c. d. e.
Rb > K > As > Se K > Rb > As > Se As > K > Rb > Se K > As > Se > Rb Rb > As > K > Se
ANS: A DIF: moderate OBJ: Arrange the atoms according to size (four atoms). TOP: Atomic Radii 154. The change in energy for which of the following processes corresponds to the first ionization
energy of magnesium? a. b. c. d. e. ANS: A DIF: easy OBJ: Identify the equation depicting the first ionization of an element. TOP: Ionization Energy 155. An atom of which of the following elements has the largest second ionization energy? a. Cs b. At c. Po d. Pb e. Ba
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ANS: A DIF: moderate OBJ: Identify the element with the largest second ionization energy. TOP: Ionization Energy 156. Which of the following form the most stable anion in the gas phase? a. b. c. d. e.
Cl (electron affinity = -349 kJ/mol) As (electron affinity = -77 kJ/mol) P (electron affinity = -72 kJ/mol) Al (electron affinity = -44 kJ/mol) Na (electron affinity = -53 kJ/mol)
ANS: A DIF: easy OBJ: Identify the most stable anion based on atom electron affinities. TOP: Electron Affinity 157. Which of the following statements is true concerning a concentrated solution of lithium oxide
in water? a. The resulting solution is strongly basic. b. The resulting solution is weakly acidic. c. The resulting solution is neither acidic nor basic. d. The resulting solution is weakly basic. e. The resulting solution is strongly acidic. ANS: A DIF: easy OBJ: Recognize a basic oxide. TOP: Oxygen and the Oxides 158. Which of the following species is isoelectronic with Ar? a. b. c. d. e. Ne ANS: B DIF: easy OBJ: Identify the atom or ion that is isoelectronic with the given element. TOP: electronic structure of atoms 159. Which of the following species would you expect to have the largest radius? a. b. P c. d. e.
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ANS: D DIF: easy OBJ: Identify the element or ion with the largest radius. TOP: Ionic Radii +
-
2-
-
160. Rank the following ions in order of decreasing ionic radii: K , Cl , Se , Br . a. Br- > Se2- > Cl- > K+ b. Se2- > Br- > Cl- > K+ c. K+> Cl- > Se2- > Brd. Br- > Cl- > Se2- > K+ e. Cl- > Se2- > K+ > BrANS: A DIF: easy OBJ: Rank the ions in order of decreasing ionic radius. TOP: Ionic Radii 161. Which of the following elements would have the highest first ionization energy? a. Beryllium b. Boron c. Carbon d. Lithium e. Silicon ANS: C OBJ: Identify the element with the highest first ionization energy. TOP: Ionization Energy 162. Choose the statement that is true: a. Outer electrons efficiently shield one another from nuclear charge b. Core electrons effectively shield outer electrons from nuclear charge c. Valence electrons are most difficult of all electrons to remove d. Core electrons have the lowest ionization energies of all electrons e. Two of the above are true. ANS: B OBJ: Identify the correct statement about shielding. TOP: Ionization Energy 163. Arrange the following atoms in order of increasing atomic radius:
arsenic oxygen bromine a. arsenic < bromine < oxygen b. arsenic < oxygen < bromine c. oxygen < bromine < arsenic d. oxygen < arsenic < bromine e. bromine < arsenic < oxygen ANS: C OBJ: Rank the elements according to atomic radii. TOP: Atomic Radii
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164. What is the oxidation state of arsenic in arsenic acid, H3AsO4? a. +1 b. -1 c. +3 d. -5
e. +5
ANS: E OBJ: Determine the oxidation state of an element in a compound. TOP: Oxidation States 165. What is the oxidation state of sulfur in sulfur dioxide, SO2? a. +1 b. -1 c. +2 d. -2
e. +4
ANS: E OBJ: Determine the oxidation state of an element in a polyatomic ion. TOP: Oxidation States 166. What is the oxidation state of phosphorus in POCl3? a. 0 b. +3 c. -3 d. +5
e. -5
ANS: D OBJ: Determine the oxidation state of an element in a compound. TOP: Oxidation States 167. Arrange the following elements in order of lowest to highest electronegativity:
Sodium, rubidium, potassium, cesium a. Na < Rb < K < Cs b. Na < K < Rb < Cs c. Cs < Rb < K < Na d. Rb < Cs < Na < K e. Cs < K < Na < Rb ANS: C OBJ: Rank the elements according to electronegativity. TOP: Electronegativity CONCEPTUAL 1. Use the screening effect to explain why a sodium atom has a larger radius than a lithium atom. OBJ: Explain nuclear shielding and its effect on the size of an atoms in the same group. TOP: Atomic Radii 2. Explain why the 1st ionization energy of N is larger than that of O. OBJ: Contrast the first ionization energies of nitrogen and oxygen. TOP: Ionization Energy 3. The 2nd ionization energy is the energy to remove a second electron. Why is IE2 of potassium much larger than IE1? Comment on the relative values of IE1 of Ne and the IE2 of Na. OBJ: Explain the large increase in the second ionization energy of the alkali metals. TOP: Ionization Energy
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4. Why are electronegativity values not usually given for Group VIIIA elements? OBJ: Explain the dearth of electronegativity values for the noble gases. TOP: Electronegativity 5. Burning fossil fuels produces SO2, a pollutant responsible for acid rain. SO2 is formed when sulfur in the fossil fuels combines with oxygen during combustion. Give several ways to reduce the amount of acid rain produced by SO2. OBJ: Suggest ways to minimize the formation acid rain from sulfur dioxide pollution. TOP: Oxygen and the Oxides 6. H2O2 fuel cells are gaining popularity as "zero emission" methods of powering an automobile. Electricity is generated when H2 and O2 forms water. Describe some ways that hydrogen and oxygen could be produced for this reaction. Would these fuel cell cars really be zero emission? OBJ: Detail several methods for production of hydrogen and oxygen. TOP: Hydrogen and the Hydrides | Oxygen and the Oxides 7. Explain why the ionic radii of cations is smaller than the atomic radii while the ionic radii of the anions are larger than the atomic radii. OBJ: Explain the size trends between ionic and atomic radii of the same element. TOP: Ionic Radii | Atomic Radii
Chapter 6—Some Types of Chemical Reactions MULTIPLE CHOICE 1. Which of the following responses contains all the true statements and no others? I. The elements at the far right of the periodic table, except the noble gases, have the greatest tendency to form anions. II. The elements with the least tendency to form ions are those at the far left of the periodic table. III. Bonds in compounds consisting of two adjacent elements in the periodic table are likely to be covalent. IV. The elements at the far left of the periodic table possess poor electrical conductivity. a. b. c. d. e.
I and III I, II, and IV II and IV I, II, and III IV
ANS: A OBJ: Know the general character and physical properties of each class of elements. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 2. Which of the following is a characteristic that describes nonmetals? a. shiny b. ductile c. good conductor d. their solids shatter when hammered Whitten 10e
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e. form cations ANS: D OBJ: Know the general character and physical properties of each class of elements. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 3. Which of the following properties would NOT be used to describe P? a. Ductile. b. Poor electrical conductor. c. Poor thermal conductor. d. Tends to form an anion. e. Will react with potassium to form an ionic compound. ANS: A OBJ: Know the general character and physical properties of each class of elements. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 4. Which of the following is a metalloid? a. Cr b. K c. U d. Si e. Pb
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ANS: D OBJ: Identify a metalloid. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 5. Which of the following is an alkali metal? a. H b. Cs c. P d. He e. Sr ANS: B OBJ: Identify an alkali metal. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 6. Which one of the following is an alkaline earth metal? a. potassium, K b. magnesium, Mg c. iron, Fe d. tin, Sn e. bromine, Br ANS: B OBJ: Identify an alkaline earth metal. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 7. Which of the following is a halogen? a. Cr b. C c. Cd d. Ca e. Br ANS: E OBJ: Identify a halogen. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 8. Which element is not correctly classified?
a. b. c. d. e.
Element / Classification S / nonmetal Ge / metalloid Se / metalloid Mo / metal In / metal
ANS: C OBJ: Classify each element. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids
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9. Which element and group are not correctly matched?
a. b. c. d. e.
Element / Periodic Group or Classification Sb / metalloid Kr / noble gas Al / alkali metal F / halogen Ca / alkaline earth metal
ANS: C OBJ: Classify each element. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 10. To which classification does strontium belong? a. alkali metal b. halogen c. alkaline earth metal d. noble gas e. metalloid ANS: C OBJ: Classify an element. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 11. Which element is not correctly classified? a. Fe / metal b. Xe / noble gas c. Cs / alkaline earth metal d. N / nonmetal e. Si / metalloid ANS: C OBJ: Classify each element. TOP: The Periodic Table: Metals, Nonmetals, and Metalloids 12. Which one of the following compounds is not a salt? a. Na2SO4 b. PCl3 c. KBr d. Ca3(PO4)2 e. NaCH3COO ANS: B OBJ: Identify the molecular compound. TOP: Aqueous Solutions – An Introduction 13. Which of the following is the BEST definition of a salt? a. A substance that produces ions in solution b. A substance that is completely ionized in solution. c. A compound composed of metals and nonmetals. d. A compound that contains a cation other than H+ and an anion other than OH or O2 e. A substance that does not produce ions in solution.
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ANS: D OBJ: Define the term salt with respect to acid-base reactions. TOP: Aqueous Solutions – An Introduction 14. Which one of the following compounds is not a salt? a. NaBr b. KClO4 c. Ca(OH)2 d. Fe(NO3)3 e. NH4I ANS: C OBJ: Identify the compound which would not result from an acid-base reaction. TOP: Aqueous Solutions – An Introduction 15. Which one of the following compounds is not a salt? a. LiI b. Al(ClO4)3 c. HI d. Fe(ClO3)3 e. NH4Br ANS: C OBJ: Identify the compound which would not result from an acid-base reaction. TOP: Aqueous Solutions – An Introduction 16. Consider the following characteristics of aqueous acidic solutions. Which of these do not describe strong acids? a. Examples include HCl, HNO3, and H2SO4. b. Are all completely soluble in water. c. All completely ionize into hydrogen ions and stable anions in dilute aqueous solution. d. Their solutions contain acid molecules. e. All of these describe strong acids. ANS: D OBJ: Define strong acid. TOP: Aqueous Solutions – An Introduction 17. Which one of the following is a strong acid? a. HF b. HNO3 c. CH3COOH d. H2SO3 e. H2CO3 ANS: B OBJ: Identify the strong acid. TOP: Aqueous Solutions – An Introduction 18. Which one of the following is a strong acid? a. HI b. HF c. HNO2 d. HCN e. HBrO Whitten 10e
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ANS: A OBJ: Identify the strong acid. TOP: Aqueous Solutions – An Introduction 19. Which statement regarding nitric acid is false? a. It only slightly ionizes in aqueous solution. b. Its solutions conduct electricity. c. It is soluble in water. d. It is a strong electrolyte. e. It produces H+ and NO3 in aqueous solution. ANS: A OBJ: Know the strong acids and identify their characteristics. TOP: Aqueous Solutions – An Introduction 20. Which one of the following is a weak acid? a. HClO4 b. HCl c. HBr d. HI e. CH3COOH ANS: E OBJ: Identify the weak acid. TOP: Aqueous Solutions – An Introduction 21. Which one of the following is a weak acid? a. HBr b. HNO3 c. HClO4 d. HCl e. HClO2 ANS: E OBJ: Identify the weak acid. TOP: Aqueous Solutions – An Introduction 22. Which one of the statements below is false concerning the following reaction: NH3(g) + H2O NH4+(aq) + OH(aq) a. b. c. d. e.
The double arrows indicate that ammonia, NH3, is only very slightly soluble in water. The reaction is reversible. When NH3 is added to H2O, NH4+ and OH ions are produced in a 1:1 ratio. When solutions of NH4Cl and NaOH are mixed, some ammonia is produced. Ammonia is considered a weak base.
ANS: A OBJ: Understand the meaning of the double arrow. TOP: Aqueous Solutions – An Introduction
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23. Which one of the following ionic hydroxides is a soluble base? a. Cu(OH)2 b. Fe(OH)2 c. Fe(OH)3 d. Sr(OH)2 e. Al(OH)3 ANS: D OBJ: Identify the soluble hydroxide. TOP: Aqueous Solutions – An Introduction 24. Which of the following is an ionization? a. HCl(aq) + NaOH(aq) NaCl(aq) + H2O b. AgNO3(aq) + LiCl(aq) AgCl(s) + LiNO3(aq) c. HBr(g) H+(aq) + Br(aq) d. 2 H2O 2 H2(g) + O2(g) e. P4(s) + 6 Cl2(g) 4 PCl3 ANS: C OBJ: Identify the balanced chemical reaction depicting an ionization. TOP: Aqueous Solutions – An Introduction 25. Which of the following statements about strong soluble bases is false? a. They are all metal hydroxides. b. They are classified as weak electrolytes. c. They produce OH in aqueous solution. d. Their solutions conduct electricity. e. They are composed of either alkali metals or some of the more reactive alkaline earth metals. ANS: B OBJ: Define strong base. TOP: Aqueous Solutions – An Introduction 26. Which one of the following is not a soluble base? a. KOH b. CsOH c. Fe(OH)2 d. Ca(OH)2 e. Ba(OH)2 ANS: C OBJ: Identify the insoluble hydroxide. TOP: Aqueous Solutions – An Introduction 27. Which one of the following substances is insoluble in water? a. RbOH b. KSCN c. BaCO3 d. LiBr e. Na3PO4 ANS: C OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction Whitten 10e
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28. Which one of the following substances is insoluble in water? a. Ba(OH)2 b. NaS c. FeS d. NaOH e. K3PO4 ANS: C OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 29. Which one of the following substances is insoluble in water? a. MgS b. Cr(CH3COO)3 c. Hg2Cl2 d. RbClO4 e. Mn(NO3)3 ANS: C OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 30. Which one of the following salts is insoluble in water? a. NaF b. NH4ClO3 c. CuCl2 d. CaSO4 e. Ba3(AsO4)2 ANS: E DIF: Harder Question OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 31. Which one of the following salts is insoluble in water? a. Na2SO4 b. K2CO3 c. Li3PO4 d. BaSO4 e. (NH4)3AsO4 ANS: D OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 32. Which one of the following salts is insoluble in water? a. (NH4)2SO4 b. CsBr c. PbCl2 d. Ca(NO3)2 e. Ba(CH3COO)2 ANS: C OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction Whitten 10e
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33. Which one of the following salts is soluble in water? a. KClO3 b. BaSO4 c. Ag3PO4 d. CuS e. FeCO3 ANS: A OBJ: Identify the soluble compound. TOP: Aqueous Solutions – An Introduction 34. Which one of the following salts is insoluble in water? a. MgSO4 b. KNO3 c. AgBr d. FeCl3 e. NaBr ANS: C OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 35. Which one of the following salts is soluble in water? a. HgS b. PbSO4 c. FeCl3 d. BaCO3 e. AgCl ANS: C OBJ: Identify the soluble compound. TOP: Aqueous Solutions – An Introduction 36. Which one of the following salts is insoluble in water? a. K2S b. NaClO c. Mg(NO3)2 d. Rb2CO3 e. Ba3(PO4)2 ANS: E OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 37. Which one of the following salts is insoluble in water? a. FeCl2 b. KCH3COO c. Pb(NO3)2 d. PbS e. NH4Cl ANS: D OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction
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38. Which one of the following salts is insoluble in water? a. Rb2SO4 b. (NH4)2S c. KI d. Cr(NO3)3 e. Ni(CO3)2 ANS: E OBJ: Identify the insoluble compound. TOP: Aqueous Solutions – An Introduction 39. Which one of the following compounds is not a strong electrolyte? a. RbF b. Ni(ClO3)2 c. Mg(NO3)2 d. HF e. HNO3 ANS: D OBJ: Identify the weak electrolyte or nonelectrolyte. TOP: Aqueous Solutions – An Introduction 40. Which one of the following is not a strong electrolyte? a. PbSO4 b. (NH4)2S c. Na2O d. HBr e. Sr(OH)2 ANS: A OBJ: Identify the weak electrolyte or nonelectrolyte. TOP: Aqueous Solutions – An Introduction 41. Which one of the following is a weak electrolyte? a. KBr b. H2SO4 c. H2CO3 d. NH4ClO e. Ca(OH)2 ANS: C OBJ: Identify the weak electrolyte. TOP: Aqueous Solutions – An Introduction 42. Which one of the following is a weak electrolyte? a. H2CO3 b. HCl c. NaCl d. (NH4)2S e. LiOH ANS: A OBJ: Identify the weak electrolyte. TOP: Aqueous Solutions – An Introduction
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43. Which one of the following is a weak electrolyte? a. HClO3 b. HCl c. Ca(OH)2 d. HClO e. NH4NO3 ANS: D OBJ: Identify the weak electrolyte. TOP: Aqueous Solutions – An Introduction 44. Which one of the following is not a strong electrolyte? a. HBr b. HCl c. HClO3 d. NaF e. HF ANS: E OBJ: Identify the weak electrolyte or nonelectrolyte. TOP: Aqueous Solutions – An Introduction 45. Which one of the following is a strong electrolyte? a. N2 b. HNO3 c. CH3COOH d. NH3 e. HNO2 ANS: B OBJ: Identify the strong electrolyte. TOP: Aqueous Solutions – An Introduction 46. Which response includes all of the following substances that are strong electrolytes, and no others? I. LiOH II. Ca(CH3COO)2 III. HClO4 IV. H3PO4 a. b. c. d. e.
I II and III II, III, and IV I and III I, II, and III
ANS: E OBJ: Identify the strong electrolytes. TOP: Aqueous Solutions – An Introduction 47. Which response includes all of the following substances that are strong electrolytes, and no others? I. Na2SO4 II. HCN III. KClO3 IV. Mn(OH)3
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a. b. c. d. e.
II, III, and IV I and II II and IV I and III I, III, and IV
ANS: D OBJ: Identify the strong electrolytes. TOP: Aqueous Solutions – An Introduction 48. Which response includes all of the following substances that are strong electrolytes, and no others? I. Na2CrO4 II. HI III. (COOH)2 IV. (NH4)2S a. b. c. d. e.
I and IV II and III I, II, and III I, II, and IV I and II
ANS: D OBJ: Identify the strong electrolytes. TOP: Aqueous Solutions – An Introduction 49. What is the total ionic equation for the following formula unit equation? BaCl2(aq) + Na2SO4(aq) BaSO4(s) + 2NaCl(aq) a. b. c. d. e.
[Ba2+(aq) + Cl(aq)] + [Na+(aq) + SO42(aq)] BaSO4(s) + [Na+(aq) + Cl(aq)] [Ba2+(aq) + 2Cl(aq)] + [2Na+(aq) + SO42(aq)] BaSO4(s) + 2[Na+(aq) + Cl(aq)] [Ba2+(aq) + 2Cl(aq)] + 2[Na+(aq) + SO42(aq)] BaSO4(s) + 2[Na+(aq) + Cl(aq)] [Ba2+(aq) + 2Cl(aq)] + [Na+(aq) + SO42(aq)] BaSO4(s) + [Na+(aq) + Cl(aq)] Ba2+(aq) + SO42(aq) BaSO4(s)
ANS: B OBJ: Identify the total ionic equation given the balanced chemical equation. TOP: Reactions in Aqueous Solutions 50. What is the total ionic equation for the following formula unit equation? HF(aq) + KOH(aq) KF(aq) + H2O a. b. c. d. e.
[H+(aq) + F(aq)] + [K+(aq) + OH(aq)] [K+(aq) + F(aq)] + [2H+ + O2 + + + [H (aq) + F (aq)] + [K (aq) + OH (aq)] [K (aq) + F (aq)] + H2O(aq) HF(aq) + [K+(aq) + OH(aq)] [K+(aq) + F(aq)] + H2O HF(aq) + [K+(aq) + OH(aq)] [K+(aq) + F(aq)] + [2H+(aq) + OH(aq)] HF(aq) + OH(aq) F(aq) + H2O
]
ANS: C OBJ: Identify the total ionic equation given the balanced chemical equation. TOP: Reactions in Aqueous Solutions
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51. What is (are) the spectator ion(s) in the following reaction? 2HClO3(aq) + Sr(OH)2(aq) Sr(ClO3)2(aq) + 2H2O a. b. c. d. e.
H+, OH H+ Sr2+, ClO3 Sr2+, OH OH
ANS: C OBJ: Identify the spectator ions. TOP: Reactions in Aqueous Solutions 52. What is the net ionic equation for the following formula unit equation? 2HClO3(aq) + Sr(OH)2(aq) Sr(ClO3)2(aq) + 2H2O a. b. c. d. e.
2HClO3(aq) + 2OH(aq) 2ClO3(aq) + 2H2O 2H+(aq) + 2OH(aq) 2H2O 2H+(aq) + Sr(OH)2(aq) Sr2+(aq) + 2H2O 2[H+(aq) + ClO3(aq)] + [Sr2+(aq) + 2OH(aq)] [Sr2+(aq) + 2ClO3(aq)] + 2H2O 2[H+(aq) + ClO3(aq)] + [Sr2+(aq) + 2OH(aq)] [Sr2+(aq) + 2ClO3(aq)] + [2H+ O2 ]
+
ANS: B OBJ: Identify the total ionic equation given the balanced chemical equation. TOP: Reactions in Aqueous Solutions 53. Which of the following anions is almost always a spectator ion? a. O2 b. OH c. NO3 d. S2 e. CO32 ANS: C OBJ: Identify the ion that generally forms soluble ionic compounds. TOP: Reactions in Aqueous Solutions 54. Which of the following cations is almost always a spectator ion? a. NH4+ b. Ag+ c. Al3+ d. Sn2+ e. Ba2+ ANS: A OBJ: Identify the ion that generally forms soluble ionic compounds. TOP: Reactions in Aqueous Solutions
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55. What is the net ionic equation for the following formula unit equation? Cu(NO3)2(aq) + H2S(aq) CuS(s) + 2HNO3(aq) a. b. c. d. e.
Cu2+(aq) + H2S(aq) CuS(s) + 2H+(aq) [Cu2+(aq) + 2NO3(aq)] + H2S(aq) CuS(s) + 2[H+(aq) + 2NO3(aq)] Cu2+(aq) + 2H+(aq) + S2(aq) CuS(s) + 2H+(aq) Cu2+(aq) + S2(aq) CuS(s) Cu2+(aq) + 2NO3(aq) + 2H+(aq) + S2(aq) CuS(s) + 2H+(aq) + 2NO3(aq)
ANS: A OBJ: Identify the net ionic equation given the balanced chemical equation. TOP: Reactions in Aqueous Solutions 56. Which of the following equations could not be a formula unit equation for the net ionic equation: H+(aq) + OH(aq) H2O a. b. c. d. e.
HCN(aq) + NaOH(aq) NaCN(aq) + H2O HNO3(aq) + NaOH(aq) NaNO3(aq) + H2O HCl(aq) + KOH(aq) KCl(aq) + H2O HClO4(aq) + LiOH(aq) LiClO4(aq) + H2O Ba(OH)2(aq) + 2HCl(aq) BaCl2(aq) + 2H2O
ANS: A DIF: Harder Question OBJ: Identify the balanced chemical equation that does not result in the given net ionic equation. TOP: Reactions in Aqueous Solutions 57. Determine the oxidation number of the underlined element in K2CO3. a. 1 b. 2 c. 4 d. +4 e. +5 ANS: D OBJ: Determine the oxidation number. TOP: Oxidation Numbers 58. Determine the oxidation number of the underlined element in SO32. a. +2 b. 2 c. +3 d. +4 e. 3 ANS: D OBJ: Determine the oxidation number. TOP: Oxidation Numbers
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59. Determine the oxidation number of the underlined element in NaMnO4. a. +1 b. +6 c. +3 d. +7 e. +5 ANS: D OBJ: Determine the oxidation number. TOP: Oxidation Numbers 60. Determine the oxidation number of the underlined element in NaNO3. a. +1 b. +2 c. +3 d. +4 e. +5 ANS: E OBJ: Determine the oxidation number. TOP: Oxidation Numbers 61. Determine the oxidation number of the underlined element in K2O2. a. 0 b. 1 c. 2 d. 3 e. 4 ANS: B OBJ: Determine the oxidation number. TOP: Oxidation Numbers 62. Determine the oxidation number of the underlined element in H2CrO4. a. +1 b. +2 c. +3 d. +4 e. +6 ANS: E OBJ: Determine the oxidation number. TOP: Oxidation Numbers 63. Determine the oxidation number of the underlined element in NH2. a. +1 b. 3 c. +3 d. 1 e. +2 ANS: B OBJ: Determine the oxidation number. TOP: Oxidation Numbers
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64. Determine the oxidation number of the underlined element in P5O10. a. +3 b. 2 c. +4 d. 1 e. +5 ANS: C OBJ: Determine the oxidation number. TOP: Oxidation Numbers 65. Determine the oxidation number of the underlined element in LiAlH4. a. +1 b. 0 c. 1 d. +2 e. 4 ANS: C OBJ: Determine the oxidation number. TOP: Oxidation Numbers 66. Determine the oxidation number of the underlined element in BrF5. a. +7 b. +5 c. +3 d. +1 e. 1 ANS: B OBJ: Determine the oxidation number. TOP: Oxidation Numbers 67. Determine the oxidation number of the underlined element in a. +1 b. +2 c. +3 d. +4 e. +5
.
ANS: A OBJ: Determine the oxidation number. TOP: Oxidation Numbers 68. Determine the oxidation number of the underlined element in H2MnO3. a. +1 b. +2 c. +3 d. +4 e. +5 ANS: D OBJ: Determine the oxidation number. TOP: Oxidation Numbers Whitten 10e
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69. Determine the oxidation number of the underlined element in a. b. c. d. e.
.
+1 +2 +3 1 2
ANS: E OBJ: Determine the oxidation number. TOP: Oxidation Numbers 70. Determine the oxidation number of the underlined element in Na2SeO4. a. +6 b. +2 c. +3 d. +4 e. +5 ANS: A OBJ: Determine the oxidation number. TOP: Oxidation Numbers 71. Determine the oxidation number of the underlined element in a. +6 b. +8 c. +3 d. +4 e. +5
.
ANS: D OBJ: Determine the oxidation number. TOP: Oxidation Numbers 72. Determine the oxidation number of the underlined element in H2P2O7. a. +6 b. +7 c. +3 d. +4 e. +5 ANS: A OBJ: Determine the oxidation number. TOP: Oxidation Numbers 73. The oxidation number of an atom is a. the number of oxygen atoms bonded. b. the number of protons in the nucleus. c. the sum of all the charges. d. the number of electrons in the atom. e. a number assigned to atoms to keep track of electron transfers. ANS: E OBJ: Define oxidation number. TOP: Oxidation Numbers Whitten 10e
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74. What are the oxidation numbers (oxidation states) of the elements in KClO2? a. K = +3 Cl = +3 O = 2 b. K = 1 Cl = 5 O = +2 c. K = +1 Cl = +5 O = 2 d. K = +1 Cl = +3 O = 2 e. K = +1 Cl = +2 O = 3 ANS: D OBJ: Determine the oxidation numbers. TOP: Oxidation Numbers 75. What are the oxidation numbers (oxidation states) of the elements in K2Cr2O7? a. K = +1 Cr = +7 O = 2 b. K = +1 Cr = +12 O = 2 c. K = +1 Cr = +6 O = 2 d. K = +1 Cr = +8 O = 2 e. K = +2 Cr = +6 O = 2 ANS: C OBJ: Determine the oxidation numbers. TOP: Oxidation Numbers 76. What are the oxidation numbers (oxidation states) of the elements in NaClO4? a. Na = +1 Cl = +9 O = 2 b. Na = +1 Cl = +7 O = 2 c. Na = +1 Cl = 1 O = 0 d. Na = +2 Cl = +6 O = 2 e. Na = +1 Cl = +5 O = 2 ANS: B OBJ: Determine the oxidation numbers. TOP: Oxidation Numbers 77. What are the oxidation numbers (oxidation states) of the elements in HCO3? a. H = +1 C = +5 O = 2 b. H = +1 C = +3 O = 2 c. H = +1 C = +2 O = 2 d. H = +2 C = +2 O = 2 e. H = +1 C = +4 O = 2 ANS: E OBJ: Determine the oxidation numbers. TOP: Oxidation Numbers 78. What are the oxidation numbers (oxidation states) of the elements in H3PO2? a. H = +1 P = +1 O = 2 b. H = +1 P = +3 O = 2 c. H = +1 P = +2 O = 2 d. H = +2 P = +2 O = 2 e. H = +1 P = +5 O = 2 ANS: A OBJ: Determine the oxidation numbers. TOP: Oxidation Numbers Whitten 10e
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79. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name CaF2 / calcium fluoride HCN / hydrogen cyanide KBr / potassium bromide Na2S / sodium sulfate Ba(SCN)2 / barium thiocyanate
ANS: D OBJ: Match the name and formula. TOP: Naming Binary Compounds 80. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name Cl2O7 / dichlorine heptoxide As4O6 / tetraarsenic oxide NO / nitrogen oxide SO3 / sulfur trioxide N2O5 / dinitrogen pentoxide
ANS: B OBJ: Match the name and formula. TOP: Naming Binary Compounds 81. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name SeO2 / selenium dioxide XeF6 / xenon hexaflouride N2O / dinitrogen oxide Sb2O3 / antimony(III) oxide S4N4 / tetrasulfur tetranitride
ANS: B OBJ: Match the name and formula. TOP: Naming Binary Compounds 82. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name Mn2O3 / manganese(II) oxide FeCl3 / ferric chloride SnBr2 / stannous bromide CuS / copper(II) sulfide CrO / chromium(II) oxide
ANS: A OBJ: Match the name and formula. TOP: Naming Binary Compounds
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83. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name CrO3 / chromium(VI) oxide AgNO3 / silver nitrate MgBr2 / magnesium(II) bromide FeS / iron(II) sulfide Al2O3 / aluminum oxide
ANS: C OBJ: Match the name and formula. TOP: Naming Binary Compounds 84. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name N2O4 / dinitrogen tetroxide P4O6 / phosphorus hexoxide OF2 / oxygen difluoride NO / nitrogen oxide Mn2O7 / manganese(VII) oxide
ANS: B OBJ: Match the name and formula. TOP: Naming Binary Compounds 85. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name FeF3 / ferric fluoride SnO / stannous oxide FeI2 / ferrous iodide Cu2S / copper(II) sulfide CuO / cupric oxide
ANS: D OBJ: Match the name and formula. TOP: Naming Binary Compounds 86. Which of the following is the formula for potassium bisulfate? a. K2SO3 b. K(SO3)2 c. KHSO4 d. KHSO3 e. K(HSO4)2 ANS: C OBJ: Identify the formula given the name. TOP: Naming Ternary Acids and Their Salts
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87. What is the correct name for NaClO? a. sodium hypochlorite b. sodium chlorite c. sodium chloride d. sodium chlorate e. sodium perchlorate ANS: A OBJ: Identify the name given the formula. TOP: Naming Ternary Acids and Their Salts 88. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name H2CO3 / carbonic acid H2SO3 / sulfurous acid HNO3 / nitric acid HClO2 / hypochlorous acid HBrO3 / bromic acid
ANS: D OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts 89. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name H3PO4 / phosphoric acid H2SO3 / sulfurous acid HClO / hypochlorous acid HClO4 / perchloric acid HNO3 / nitrous acid
ANS: E OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts 90. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name KBrO / potassium hypobromite K2SO4 / potassium sulfate K2BrO4 / potassium perbromate KNO2 / potassium nitrite K2CO3 / potassium carbonate
ANS: C OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts
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91. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name NaClO3 / sodium chlorate LiClO2 / lithium chlorite KBrO / potassium hypobromite MgClO4 / magnesium perchlorate NaIO3 / sodium iodate
ANS: D OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts 92. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name LiClO2 / lithium chlorite HIO3 / periodic acid HClO2 / chlorous acid HBrO / hypobromous acid Sr(ClO4)2 / strontium perchlorate
ANS: B OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts 93. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name HIO / hypoiodous acid NaHSO4 / sodium hydrogen sulfate HNO3 / nitric acid H4SiO4 / silicic acid KH2PO4 / potassium hydrogen phosphate
ANS: E OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts 94. Which of the following matched pairs of name and formula has an error?
a. b. c. d. e.
Formula / Name Al(NO2)3 / aluminum nitrate BaSO3 / barium sulfite Cr(SCN)3 / chromium(III) thiocyanate N2O3 / dinitrogen trioxide Sb4O6 / tetraantimony hexoxide
ANS: A OBJ: Match the name and formula. TOP: Naming Ternary Acids and Their Salts
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95. What is the correct name for NH4ClO3? a. nitrogen chlorate b. tetraammonium trichloride c. ammonium chloride d. tetraammonium chlorite e. ammonium chlorate ANS: E OBJ: Identify the name given the formula. TOP: Naming Ternary Acids and Their Salts 96. Which of the following statements best describes an oxidizing agent? a. A substance that is reduced and causes oxidation of another substance. b. A substance that increases the number of oxygen atoms bonded. c. A substance that is oxidized and causes reduction of another substance. d. A substance that reacts with oxygen. e. A substance that contains more than one oxygen atom. ANS: A OBJ: Define oxidizing agent. TOP: Oxidation-Reduction Reactions 97. Which response contains all of the following that are oxidation-reduction reactions and no others? I. PCl3 + 3H2O 3HCl(aq) + H3PO3(aq) II. Fe2O3(s) + 3CO(g) 2Fe(s) + 3CO2(g) III. CaCO3(s) + 2HClO3(aq) Ca(ClO3)2(aq) + CO2(g) + H2O a. b. c. d. e.
I II III II and III I and II
ANS: B OBJ: Identify the redox reactions. TOP: Oxidation-Reduction Reactions 98. What is the oxidizing agent in the following reaction? 8H+(aq) + 3C2H5OH(aq) + Cr2O72(aq) 2Cr3+(aq) + 3C2H4O(aq) + 7H2O a. b. c. d. e.
H+ Cr2O72 Cr3+ C2H5OH H2O
ANS: B OBJ: Identify the oxidizing agent. TOP: Oxidation-Reduction Reactions
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99. Which response includes all the following that are oxidation-reduction reactions, and no others? I. BaSO3(s) BaO(s) + SO2(g) II. 2K(s) + Br2 2KBr(s) III. H2CO3(aq) + Ca(OH)2(aq) CaCO3(s) + 2H2O IV. SnS2(s) + 6HCl(aq) H2SnCl6(s) + 2H2S(aq) V. 3Cl2(g) + 6KOH(aq) 5KCl(aq) + KClO3(aq) + 3H2O a. b. c. d. e.
II, III, and IV I and III II and V I and IV another one or another combination
ANS: C OBJ: Identify the redox reactions. TOP: Oxidation-Reduction Reactions 100. What is the oxidizing agent in the following reaction? 6KOH(aq) + 3Cl2(g) KClO3(aq) + 5KCl(aq) + 3H2O a. b. c. d. e.
KOH Cl2 KClO3 KCl H2O
ANS: B DIF: Harder Question OBJ: Identify the oxidizing agent. TOP: Oxidation-Reduction Reactions 101. What is the reducing agent in the following reaction? Cu(s) + 4H+(aq) + SO42(aq) Cu2+(aq) + 2H2O a. b. c. d. e.
+ SO2(g)
Cu H+ SO42 Cu2+ SO2
ANS: A OBJ: Identify the reducing agent. TOP: Oxidation-Reduction Reactions 102. What is the reducing agent in the following reaction? 6KOH(aq) + 3Cl2(g) KClO3(aq) + 5KCl(aq) + 3H2O a. b. c. d. e.
KOH Cl2 KClO3 KCl H2O
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ANS: B DIF: Harder Question OBJ: Identify the reducing agent. TOP: Oxidation-Reduction Reactions 103. The reducing agent is ____, and it is ____ in the following reaction. 2MnO4(aq) + 3S2(aq) + 4H2O 2MnO2(s) + 3S(s) + 8OH(aq) a. b. c. d. e.
MnO4; oxidized S2; oxidized MnO4; reduced S2; reduced H2O; reduced
ANS: B OBJ: Identify the reducing agent and whether it is oxidized or reduced. TOP: Oxidation-Reduction Reactions 104. In the following reaction NaClO3 is ____. 5NaClO3(aq) + 3H2O + 3I2(s) 6HIO3(aq) + 5NaCl(aq) a. b. c. d. e.
the oxidizing agent and is oxidized. the oxidizing agent and is reduced. the reducing agent and is oxidized. the reducing agent and is reduced. neither an oxidizing agent nor a reducing agent.
ANS: B OBJ: Identify a species as the oxidizing or reducing agent and whether it is reduced or oxidized. TOP: Oxidation-Reduction Reactions 105. In the following reaction, the ferric ion is ____. 2FeBr3(aq) + 3Cl2(g) 2FeCl3(aq) + 3Br2 a. b. c. d. e.
the oxidizing agent and is oxidized. the oxidizing agent and is reduced. the reducing agent and is oxidized. the reducing agent and is reduced. neither an oxidizing agent nor a reducing agent.
ANS: E OBJ: Identify a species as the oxidizing or reducing agent and whether it is reduced or oxidized. TOP: Oxidation-Reduction Reactions 106. In the following reaction oxygen is ____. 2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O a. b. c. d. e.
the oxidizing agent and is oxidized. the oxidizing agent and is reduced. the reducing agent and is oxidized. the reducing agent and is reduced. neither an oxidizing agent nor a reducing agent.
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ANS: B OBJ: Identify a species as the oxidizing or reducing agent and whether it is reduced or oxidized. TOP: Oxidation-Reduction Reactions 107. In the following reaction, Cl2 is ____. Cl2(g) + H2O HCl(aq) + HClO(aq) a. b. c. d. e.
the oxidizing agent. the reducing agent. both the oxidizing agent and the reducing agent neither an oxidizing agent nor a reducing agent. none of these.
ANS: C OBJ: Identify a species as the oxidizing or reducing agent and whether it is reduced or oxidized. TOP: Oxidation-Reduction Reactions 108. Which of the following reactions is a combination reaction? a. AgNO3(aq) + HCl(aq) AgCl(s) + HNO3(aq) b. Na2O(s) + CO2(g) Na2CO3(s) c. C3H8(g) + 5O2(g) 3CO2(g) + 4H2O d. 2H2O 2H2(g) + O2(g) e. KOH(aq) + HCl(aq) KCl(aq) + H2O ANS: B OBJ: Identify the combination reaction. TOP: Combination Reactions 109. When two nonmetals combine, ____. a. they form a binary ionic compound. b. they form a binary covalent compound. c. they release hydrogen gas. d. they form two or more products. e. they neutralize the acid formed in the reaction. ANS: B OBJ: Identify the product of a nonmetal-nonmetal reaction. TOP: Combination Reactions 110. Which of the following reactions is not a combination reaction? a. 2CO(g) + O2(g) 2CO2(g) b. PBr3 + Br2 PBr5(s) c. AgNO3(aq) + HCl(aq) AgCl(s) + HNO3(aq) d. 2Ca(s) + O2(g) 2CaO(s) e. CO2(g) + H2O H2CO3(aq) ANS: C OBJ: Identify the combination reactions. TOP: Combination Reactions
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111. Which of the following is both a combination reaction and a reduction-oxidation reaction? a. H2CO3(aq) CO2(g) + H2O b. Zn(s) + CuNO3(aq) Cu(s) + ZnNO3(aq) c. Ca(OH)2(aq) + 2HCl(aq) CaCl2(aq) + 2H2O d. 2H2(g) + O2(g) 2H2O e. CaO(s) + CO2(g) CaCO3(s) ANS: D OBJ: Identify the combined combination and redox reaction. TOP: Combination Reactions 112. Which of the following statements about a decomposition reaction is not true? a. It may or may not also be an oxidation-reduction reaction. b. It may produce two elements as products. c. It may also be a combination reaction. d. It may produce an element and a compound as products. e. It may produce two different compounds as products. ANS: C OBJ: Define decomposition reaction. TOP: Decomposition Reactions 113. Which of the following reactions is a decomposition reaction? a. 2H2(g) + O2(g) 2H2O b. Fe2O3(s) + 3CO(g) 2Fe(s) + 3CO2(g) c. C3H8(g) + 5O2(g) 3CO2(g) + 4H2O d. 2AgNO3(aq) + Zn(s) 2Ag(s) + Zn(NO3)2(aq) e. 2KClO3(s) 2KCl(s) + 3O2(g) ANS: E OBJ: Identify the decomposition reaction. TOP: Decomposition Reactions 114. Which of the following is both a decomposition reaction and a reduction-oxidation reaction? a. H2CO3(aq) CO2(g) + H2O b. Zn(s) + CuNO3(aq) Cu(s) + ZnNO3(aq) c. Ca(OH)2(aq) + 2HCl(aq) CaCl2(aq) + 2H2O d. 2NH4NO3(s) 2N2(g) + O2(g) + 4H2O(g) e. CaCO3(s) CaO(s) + CO2(g) ANS: D OBJ: Identify the combined decomposition and redox reaction. TOP: Decomposition Reactions 115. Which of the following reactions is not a decomposition reaction? a. 2HgO(s) 2Hg + O2(g) b. H2(g) + Cl2(g) 2HCl(g) c. NH4NO3(s) N2O(g) + 2H2O(g) d. Mg(OH)2(s) MgO(s) + H2O(g) e. 2H2O2(aq) 2H2O + O2(g) ANS: B OBJ: Identify the decomposition reactions. TOP: Decomposition Reactions
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116. Which of the following reactions is not a decomposition reaction? a. C4H8(g) + 6O2(g) 4CO2(g) + 4H2O b. Na2CO3(s) Na2O(s) + CO2(g) c. 2KClO3(s) 2KCl(s) + 3O2(g) d. 2H2O 2H2(g) + O2(g) e. BaSO3(s) BaO(s) + SO2(g) ANS: A OBJ: Identify the decomposition reactions. TOP: Decomposition Reactions 117. Which response includes all of the following that are displacement reactions, and no other reactions? I. P4O10(s) + 6Na2O(s) 4Na3PO4(s) II. 2AgNO3(aq) + Zn(s) 2Ag(s) + Zn(NO3)2(aq) III. Ca(s) + 2HCl(aq) CaCl2(aq) + H2(g) IV. Fe(OH)2(s) + 2HCl(aq) FeCl2(aq) + 2H2O a. b. c. d. e.
I and II II and III II and IV I and III I, III, and IV
ANS: B OBJ: Identify the displacement reactions. TOP: Displacement Reactions 118. Which of the following is a displacement reaction? a. Li2O(s) + CO2(g) Li2CO3(s) b. Cl2(g) + 2NaBr(aq) Br2 + 2NaCl(aq) c. HNO3(aq) + KOH(aq) KNO3(aq) + H2O d. SO3 + H2O H2SO4 e. CaCO3(s) CaO(s) + CO2(g) ANS: B OBJ: Identify the displacement reactions. TOP: Displacement Reactions 119. Which of the following metals could displace hydrogen from sulfuric acid and form hydrogen gas? a. Cu b. Au c. Hg d. Zn e. none of these ANS: D OBJ: Identify the metal that reacts with sulfuric acid. TOP: Displacement Reactions
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120. Which response includes all of the following that are displacement reactions, and no other reactions? I. 2KBr(aq) + F2(g) 2KF(aq) + Br2 II. N O (g) NO(g) + NO (g) 2
III. IV. a. b. c. d. e.
3
PF3(g) + F2(g) PF5(g) 2Na(s) + 2H2O
2
2NaOH(aq) + H2(g)
I and IV I and II II, III, and IV II and IV I, II, and IV
ANS: A OBJ: Identify the displacement reactions. TOP: Displacement Reactions 121. Which of the following is the most active metal? a. Na b. K c. Mg d. Zn e. Al ANS: B OBJ: Apply the activity series. TOP: Displacement Reactions 122. Which one of the following acids does not produce H2(g) as a major product of reaction with a moderately active metal like zinc? a. H2SO4 b. HCl c. HClO4 d. HClO3 e. HNO3 ANS: E OBJ: Identify the acid that does produce hydrogen with zinc. TOP: Displacement Reactions 123. Which one of the following metals is least active? a. Ca b. K c. Pt d. Li e. Al ANS: C OBJ: Apply the activity series. TOP: Displacement Reactions
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124. Which one of the following ions would be displaced from aqueous solution by magnesium? a. Ca2+ b. Cu2+ c. Li+ d. K+ e. Na+ ANS: B OBJ: Apply the activity series. TOP: Displacement Reactions 125. Which metal will NOT displace hydrogen from either water or HCl? a. Ag b. Pb c. Zn d. Al e. Na ANS: A OBJ: Apply the activity series. TOP: Displacement Reactions 126. Which one of the following elements reacts with water at room temperature to produce hydrogen? a. Ti b. Zn c. Ca d. Mg e. Al ANS: C OBJ: Apply the activity series. TOP: Displacement Reactions 127. Which response includes all of the following reactions that will occur in aqueous solution, and no others? I. 2NaF(aq) + Cl2(g) 2NaCl(aq) + F2(g) II. 2NaCl(aq) + I2(s) 2NaI(aq) + Cl2(g) III. 2NaBr(aq) + Cl2(g) 2NaCl(aq) + Br2 IV. 2NaI(aq) + Br2 2NaBr(aq) + I2(s) V. 2NaBr(aq) + I2(s) 2NaI(aq) + Br2 a. b. c. d. e.
I, II, and III III and IV II, IV, and V I and III III, IV, and V
ANS: B OBJ: Identify the halogen-halide ion combinations that react. TOP: Displacement Reactions
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128. Which of the following reactions is NOT spontaneous? a. 2KCl(aq) + F2(g) 2KF(aq) + Cl2(g) b. 2KCl(aq) + I2(s) 2KI(aq) + Cl2(g) c. 2Na(s) + 2H2O 2NaOH(aq) + H2(g) d. 2K(s) + ZnSO4(aq) K2SO4(aq) + Zn(s) e. 2NaI(aq) + Br2 2NaBr(aq) + I2(s) ANS: B OBJ: Identify the spontaneous reactions. TOP: Displacement Reactions 129. Which one of the following represents the net ionic equation for the reaction of nitric acid with aluminum hydroxide? a. 3H+(aq) + Al(OH)3(s) Al3+(aq) + 3H2O b. 3HNO3(aq) + Al(OH)3(s) 3Al(NO3)3(aq) + 3H2O c. 2H+(aq) + Al(OH)2(s) Al2+(aq) + 2H2O d. H+(aq) + OH(aq) H2O e. 3NO3(aq) + Al3+(aq) Al(NO3)3(aq) ANS: A OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions 130. Metathesis reactions always result in ____. a. removal of ions from solution. b. release of hydrogen gas. c. formation of a precipitate. d. formation of cations. e. neutralization of an acid. ANS: A OBJ: Define metathesis reaction. TOP: Metathesis (Acid-Base) Reactions 131. Which of the following represents the net ionic reaction for all strong acid / strong base reactions that produce a soluble salt? a. 2H+(aq) + 2e H2(g) b. 2H+(aq) + 2H2O 4OH(aq) + c. H (aq) + OH (aq) H2O d. H2O + OH(aq) O2(g) + 3/2H2(g) + e. 2H (aq) + O2(aq) 2H2O ANS: C OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions 132. Write the balanced formula unit equation for the complete reaction of barium hydroxide with perchloric acid. What is the coefficient of H2O? a. 1 b. 2 c. 3 d. 4 e. 5
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ANS: B OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 133. Write the formula unit equation for the complete reaction of hydrobromic acid with calcium hydroxide. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 3 d. 4 e. 5 ANS: A OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 134. Write the balanced formula unit equation for the complete neutralization of dilute H2SO4 with KOH in aqueous solution. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 8 c. 9 d. 4 e. 5 ANS: A OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 135. What salt is formed when aqueous calcium hydroxide is mixed with phosphoric acid? a. CaPO4 b. Ca(OH)2 c. Ca3(PO4)2 d. P(OH)3 e. no salt formation occurs ANS: C OBJ: Identify the product of an acid-base reaction. TOP: Metathesis (Acid-Base) Reactions 136. Write the balanced formula unit equation for the reaction of chloric acid with aqueous ammonia. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 7 b. 8 c. 3 d. 4 e. 6 ANS: C OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions
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137. Write the balanced formula unit equation for the reaction of sulfurous acid with lithium hydroxide. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 7 b. 8 c. 3 d. 4 e. 6 ANS: D OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 138. Write the formula unit equation for the complete reaction of Ca(OH)2 with H2S. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 3 d. 4 e. 5 ANS: E OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 139. Write the formula unit equation for the complete reaction of LiOH with oxalic acid, (COOH)2. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 8 d. 4 e. 5 ANS: A DIF: Harder Question OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 140. Write the balanced formula unit equation for the complete neutralization of dilute H3PO4 with Ca(OH)2 in aqueous solution. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 10 b. 12 c. 14 d. 16 e. 18 ANS: B OBJ: Write the balanced chemical equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions
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141. The following generalized equation represents the net ionic reaction of which type of reaction? HA(aq) + OH(aq) A(aq) + H2O a. b. c. d. e.
The reaction between a weak acid and a strong base, which produces a soluble salt. The reaction between a strong acid and a strong base, which produces a soluble salt. The reaction between a weak acid and a weak base, which produces a soluble salt. The reaction between a weak acid and a strong base, which produces an insoluble salt. The reaction between a soluble salt and a strong base, which produces water.
ANS: A OBJ: Classify the reaction. TOP: Metathesis (Acid-Base) Reactions 142. The precipitate that forms when aqueous solutions of barium chloride and potassium sulfate are mixed is: a. BaCl2 b. K2SO4 c. BaSO4 d. KCl e. no precipitate is formed. ANS: C OBJ: Identify the products given the reactants. TOP: Metathesis (Acid-Base) Reactions 143. Write the balanced total ionic equation for the reaction of nitric acid with aqueous ammonia. What is the coefficient preceding NH3? a. 1 b. 2 c. 3 d. 4 e. 5 ANS: A OBJ: Write the total ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions 144. Write the balanced total ionic equation for the complete reaction of phosphoric acid and calcium hydroxide. What is the coefficient preceding water in this equation? a. 6 b. 8 c. 12 d. 4 e. 5 ANS: A OBJ: Write the total ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions
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145. Consider the complete neutralization of HBr by Ca(OH)2. Which of the following statements about this neutralization is false? a. CaBr2 is the salt formed. b. The production of water is the driving force for the this reaction. c. The salt formed is insoluble in water. d. HBr is a strong acid and Ca(OH)2 is a strong base. e. No gas is formed in this reaction. ANS: C OBJ: Identify the products given the reactants and describe the chemical nature of the reactants and products. TOP: Metathesis (Acid-Base) Reactions 146. Write the net ionic equation for the complete reaction of barium hydroxide and hydrochloric acid. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 3 b. 7 c. 8 d. 4 e. 5 ANS: A OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 147. Write the balanced net ionic equation for the complete neutralization of dilute sulfuric acid with potassium hydroxide in aqueous solution. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 8 c. 3 d. 4 e. 5 ANS: C OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 148. Write the net ionic equation for the complete neutralization of calcium hydroxide with dilute sulfuric acid. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 4 d. 3 e. 5 ANS: D OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions
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149. Write the balanced net ionic equation for the reaction of HClO3 with aqueous NH3. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 7 b. 8 c. 3 d. 4 e. 5 ANS: C OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 150. Write the balanced net ionic equation for the complete neutralization of chromium (III) hydroxide with sulfuric acid. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 11 b. 8 c. 16 d. 18 e. 22 ANS: B OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 151. Consider the neutralization of H2SO3 by LiOH. Which of the following is a product? a. lithium sulfite b. dilithium sulfite c. lithium hydroxide d. sulfuric acid e. lithium sulfate ANS: A OBJ: Identify the products given the reactants. TOP: Metathesis (Acid-Base) Reactions 152. Write the net ionic equation for the complete reaction of carbonic acid with potassium hydroxide. What is the total charge on the ions on the right side of the equation? a. 1+ b. 2+ c. 3+ d. 2 e. 1 ANS: D OBJ: Write the net ionic equation given the reactants.| Calculate the net charge of the reactants. TOP: Metathesis (Acid-Base) Reactions 153. Write the balanced net ionic equation for the complete neutralization of H2SO3 with aqueous NaOH. What is the total charge on the right side of the balanced equation? a. 1 b. 2 c. 6 d. 4 e. 8 Whitten 10e
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ANS: B OBJ: Write the net ionic equation given the reactants.| Calculate the net charge of the reactants. TOP: Metathesis (Acid-Base) Reactions 154. Write the net ionic equation for the complete reaction of lithium hydroxide with oxalic acid, (COOH)2. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 8 d. 4 e. 5 ANS: A DIF: Harder Question OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 155. Write the balanced net ionic equation for the complete reaction of phosphoric acid and calcium hydroxide. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 10 b. 12 c. 18 d. 4 e. 19 ANS: C OBJ: Write the net ionic equation given the reactants. | Sum the coefficients. TOP: Metathesis (Acid-Base) Reactions 156. Identify the net ionic equation for the reaction of HClO2 and lithium hydroxide. a. HClO2(aq) + OH(aq) ClO2(aq) + H2O b. HClO2(aq) + 2OH(aq) ClO2(aq) + 2H2O c. 2HClO2(aq) + Ba(OH)2(aq) Ba(ClO2)2(aq) + 2H2O d. H+(aq) + OH(aq) H2O e. 2HClO2(aq) + OH(aq) 2ClO2(aq) + 2H2O ANS: A OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions 157. Will a precipitate form when 0.1 M aqueous solutions of AgNO3 and NaCl are mixed? If a precipitate does form, identify the precipitate and give the net ionic equation for the reaction. a. No precipitate forms. b. AgCl precipitates. Ag+(aq) + Cl(aq) AgCl(s) c. Ag3N precipitates. 6Ag+(aq) + 2NO3(aq) 2Ag3N(s) + 3O2(g) d. AgCl precipitates. Ag+(aq) + NaCl(aq) AgCl(s) + Na+(aq) e. NaNO3 precipitates. NO3(aq) + Na+(aq) NaNO3(s) ANS: B OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions
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158. What ions are almost completely removed from solution when 0.1 M aqueous solutions of HBr and Pb(CH3COO)2 are mixed? Choose the response that includes all the ions removed. I. H+ II. Br III. Pb2+ IV. CH3COO a. b. c. d. e.
II and III I and IV I, II, III and IV III and IV II, III and IV
ANS: C OBJ: Identify the ions consumed in the reaction. TOP: Metathesis (Acid-Base) Reactions 159. Will a precipitate form when 0.1 M aqueous solutions of Ba(NO3)2 and H2CO3 are mixed? If a precipitate does form, identify the precipitate and give the net ionic equation for the reaction. a. No precipitate forms. b. BaCO3 precipitates. Ba2+(aq) + CO32(aq) BaCO3(s) c. BaCO3 precipitates. Ba2+(aq) + H2CO3(aq) BaCO3(s) + H2(g) d. BaCO3 precipitates. Ba2+(aq) + H2CO3(aq) BaCO3(s) + 2H+(aq) e. H2(NO3)2 precipitates. 2H+(aq) + 2NO3(aq) H2(NO3)2(s) ANS: D OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions 160. Will a precipitate form when 0.1 M aqueous solutions of CrCl3 and (NH4)2S are mixed? If it does form, identify the precipitate and give the net ionic equation for the reaction. a. No precipitate forms. b. NH4Cl precipitates. NH4+(aq) + Cl(aq) NH4Cl (s) c. Cr2S3 precipitates. 2Cr3+(aq) + 3S2(aq) Cr2S3(s) d. Cr3S2 precipitates. 3Cr3+(aq) + 2S2(aq) Cr3S2(s) e. Cr2S3 precipitates. 2CrCl3(aq) + 3(NH4)2S(aq) Cr2S3(s) + 6NH4Cl(aq) ANS: C OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions 161. Will a precipitate form when 0.1 M aqueous solutions of NH4NO3 and NaBr are mixed? If it does form, identify the precipitate and give the net ionic equation for the reaction. a. No precipitate forms. b. NaNO3 precipitates. Na+(aq) + NO3(aq) NaNO3(s) c. NH4BrO3 precipitates. NH4+(aq) + NO3(aq) + Br(aq) NH4BrO3(s) + N2 d. NH4N precipitates. 2NH4+(aq) + 2NO3(aq) 2NH4N(s) + 3O2(g) e. NH4Br precipitates. NH4+(aq) + Br(aq) NH4Br(s) ANS: A OBJ: Identify the net ionic equation given the reactants. TOP: Metathesis (Acid-Base) Reactions
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162. The equation, 2H+(aq) + CO32(aq) H2O an aqueous mixture of a. CaCO3 and HCl. b. Na2CO3 and HCl. c. H2CO3 and NaOH. d. BaCO3 and H2SO4. e. (COOH)2 and KOH.
+ CO2(g), is the net ionic equation for the reaction of
ANS: B OBJ: Identify the reactants consistent with the net ionic reaction. TOP: Gas-Formation Reactions 163. The equation, 2H+(aq) + SO32(aq) H2O aqueous mixture of a. BaSO3 and H2SO4. b. H2SO4 and CaSO3. c. K2SO3 and HCl. d. PbSO3 and HBr. e. K2SO4 and HCl.
+ SO2(g), is the net ionic equation for the reaction of an
ANS: C OBJ: Identify the reactants consistent with the net ionic equation. TOP: Gas-Formation Reactions 164. Which of the following equations is the net ionic equation for the reaction of iron(II) sulfide and hydrochloric acid? a. S2(aq) + 2H+(aq) 2H2S(g) b. Fe2S3(s) + 6H+(aq) 3H2S(g) + 2Fe3+(aq) c. Fe2+(aq) + 2Cl FeCl2(s) d. FeS(s) + 2H+(aq) Fe2+(aq) + H2S(g) e. Fe2S(s) + 2H+(aq) Fe22+ + H2S(g) ANS: D OBJ: Identify the reactants consistent with the net ionic equation. TOP: Gas-Formation Reactions 165. Which of the following is not a metathesis reaction? a. CH4(g) + 2O2(g) CO2(g) + 2H2O b. FeS(s) + 2HCl(aq) FeCl2(aq) + H2S(g) c. CaCl2(aq) + K2CO3(aq) CaCO3(s) + 2KCl(aq) d. 2HCl(aq) + Ba(OH)2(aq) BaCl2(aq) + 2H2O e. AgNO3(aq) + NaBr(aq) AgBr(s) + NaNO3(aq) ANS: A OBJ: Identify the metathesis reactions. TOP: Gas-Formation Reactions 166. The driving force of a metathesis reaction is the removal of ions from the solution. Which of the following statements is not true for a metathesis reaction? a. No change in oxidation numbers occurs during a metathesis reaction. b. The driving force may be the formation of an insoluble solid compound. c. The driving force may be the formation of an insoluble or slightly soluble gas. d. The driving force may be the formation of weak or nonelectrolyte such as water. e. The driving force may be the reduction of an ion into an insoluble element. Whitten 10e
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ANS: E OBJ: Recognize the possible products of a metathesis reaction. TOP: Summary of Reaction Types 167. Which of the following "generic" reactions is an example of metathesis? a. AB + CD AD + CB b. A + B AB c. A + BC AC + B d. AB A + B ANS: A OBJ: Identify the general form of a metathesis reaction. TOP: Summary of Reaction Types 168. Which of the following reactions is (are) metathesis reactions? I. 2NaCl(aq) + Hg2(NO3)2(aq) Hg2Cl2(s) + 2NaNO3(aq) II. H2SO4(aq) + 2NaOH(aq) Na2SO4(aq) + 2H2O III. K2CO3(aq) + 2HCl(aq) 2KCl(aq) + H2O + CO2(g) a. b. c. d. e.
only I only II only III I, II and III only I and II
ANS: D OBJ: Identify the metathesis reactions. TOP: Summary of Reaction Types 169. Which of the following is a reduction-oxidation (redox) reaction? a. FeCl2(aq) + 2AgNO3(aq) 2AgCl(aq) + Fe(NO3)2(aq) b. AgNO3(aq) + NaBr(aq) AgBr(s) + NaNO3(aq) c. Zn(s) + 2AgNO3(aq) 2Ag(s) + Zn(NO3)2(aq) d. CaO(s) + CO2(g) CaCO3(s) e. 3HCl(aq) + Cr(OH)3(s) CrCl3(aq) + 3H2O ANS: C OBJ: Identify the redox reaction. TOP: Summary of Reaction Types 170. Classify the following reaction by giving the reaction type that applies. 2NiS(s) + 3O2(g) a. b. c. d. e.
2NiO(s) + 2SO2(g)
redox combination decomposition displacement metathesis
ANS: A OBJ: Classify the reaction. TOP: Summary of Reaction Types
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171. Classify the following reaction by giving the reaction type that applies. 2HI(aq) + Ba(OH)2(aq) 2H2O + BaI2(aq) a. b. c. d. e.
redox combination decomposition displacement metathesis
ANS: E OBJ: Classify the reaction. TOP: Summary of Reaction Types 172. Classify the following reaction by giving all of these reaction type(s) that apply. 2PbO(s) + O2(g) 2PbO2(s) I. II. III. IV. V. a. b. c. d. e.
redox combination decomposition displacement metathesis I and V only II I and II only III only V
ANS: C OBJ: Classify the reaction. TOP: Summary of Reaction Types 173. Classify the following reaction by giving all of these reaction type(s) that apply. 2KClO3(aq) 2KCl(aq) + 3O2(g) I. II. III. IV. V. a. b. c. d. e.
redox combination decomposition displacement metathesis I and III only II I and II only IV only V
ANS: A OBJ: Classify the reaction. TOP: Summary of Reaction Types
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174. Classify the following reaction by giving all of these reaction type(s) that apply. SnCl2(aq) + 2HgCl2(aq) SnCl4(aq) + Hg2Cl2(s) I. II. III. IV. V. a. b. c. d. e.
redox combination decomposition displacement metathesis only I only II only III only IV only V
ANS: A OBJ: Classify the reaction. TOP: Summary of Reaction Types 175. Classify the following reaction by giving all of these reaction type(s) that apply. CH4(g) + Br2 CH3Br(g) + HBr(g) I. II. III. IV. V. a. b. c. d. e.
redox combination decomposition displacement metathesis only I only II only III only IV I and V
ANS: A OBJ: Classify the reaction. TOP: Summary of Reaction Types 176. Classify the following reaction by giving all of these reaction type(s) that apply. Ba(OH)2(aq) + Na2CO3(aq) BaCO3(s) + 2NaOH(aq) I. II. III. IV. V. a. b. c. d. e.
redox combination decomposition displacement metathesis only I only II only V only IV II and III
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ANS: C OBJ: Classify the reaction. TOP: Summary of Reaction Types 177. Classify the following reaction by giving all of these reaction type(s) that apply. C2H4(g) + Br2 C2H4Br2(g) I. II. III. IV. V. a. b. c. d. e.
redox combination decomposition displacement metathesis only III only II I and II II and IV II and V
ANS: C OBJ: Classify the reaction. TOP: Summary of Reaction Types 178. Classify the following reaction by giving all of these reaction type(s) that apply. 2NH4NO3(s) I. II. III. IV. V. a. b. c. d. e.
2N2(g) + O2(g) + 4H2O(g)
redox combination decomposition displacement metathesis I and V only II only III I and III only V
ANS: D OBJ: Classify the reaction. TOP: Summary of Reaction Types 179. Classify the following reaction by giving all of these reaction type(s) that apply. Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g) I. II. III. IV. V.
redox combination decomposition displacement metathesis
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a. b. c. d. e.
only I only II only III only V I and IV
ANS: E OBJ: Classify the reaction. TOP: Summary of Reaction Types 180. Which of the following "generic" reactions is an example of decomposition? a. AB + CD AD + CB b. A + B AB c. A + BC AC + B d. AB A + B ANS: D OBJ: Identify the general form of a decomposition reaction. TOP: Summary of Reaction Types 181. Which of the following "generic" reactions is an example of combination? a. AB + CD AD + CB b. A + B AB c. A + BC AC + B d. AB A + B ANS: B OBJ: Identify the general form of a combination reaction. TOP: Summary of Reaction Types 182. Which of the following compounds is soluble in water? a. b. c. d. e.
Sc2S3 Na2O FeS Hg2Cl2 CdS
ANS: B DIF: easy OBJ: Identify the water soluble ionic compound. TOP: Reactions in Aqueous Solutions 183. Which of the following compounds is insoluble in water? a. NH4I b. KI c. ZnCl2 d. Hg2I2 e. NaI
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ANS: D DIF: moderate OBJ: Identify the water insoluble ionic compound. TOP: Reactions in Aqueous Solutions . 184. Which anion will form a precipitate with Ca2+? a. b. c. d. e.
Cl– OH– C2H3O2– Br– none of the above
ANS: B DIF: easy OBJ: Identify the anion that will precipitate the given cation. TOP: Reactions in Aqueous Solutions 185. Which of the following is a strong acid in aqueous solution? a. b. c. d. e.
HOCH2CH2OH Sr(OH)2 CH3COOH NH3 HNO3
ANS: E DIF: easy OBJ: Identify the formula of a strong acid. TOP: Reactions in Aqueous Solutions 186. The balanced net ionic equation for the reaction of barium sulfite with nitric acid is a. BaSO3(s) + 2H+(aq) Ba2+(aq) + SO2(g) + H2O(l). b. Ba2+(aq) + CO32–(aq) + 2H+(aq) + 2NO3–(aq) Ba(NO3)2(aq) + SO2(g) + H2O(l). c. BaSO3(s) + 2HNO2(aq) Ba2+(aq) + 2NO2–(aq) + SO2(g) + H2O(l). d. Ba(HSO3)2(s) + 2HNO3(aq) Ba2+(aq) + 2NO3–(aq) + SO2(g) + 2H2O(l). e. BaSO3(s) + 2HNO3(aq) Ba2+(aq) + 2NO3–(aq) + SO2(g) + H2O(l). ANS: A DIF: moderate OBJ: Identify the balanced net ionic equation of a gas formation reaction given the reactants. TOP: Gas-Formation Reactions 187. What is the oxidation number of Ba in BaFeO4? a. b. c. d. e.
+6 -2 +2 +3 0
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ANS: C DIF: moderate OBJ: Determine the oxidation number. TOP: Oxidation Numbers 188. In the following reaction, which species is oxidized?
3Ag2S(s) + 8H+(aq) + 2NO3–(aq) 6Ag+(aq) + 3S(s) + 2NO(g) + 4H2O a. b. c. d. e.
NO3– Ag2S Ag+ NO H+
ANS: B DIF: moderate OBJ: Identify the species which is oxidized. TOP: Oxidation-Reduction Reactions 189. Which equation best represents the net ionic equation for the reaction that occurs when
aqueous solutions of lithium phosphate and magnesium nitrate are mixed? a. b. c. d. e.
3Mg2+(aq) + 2PO43–(aq) Mg3(PO4)2(s) 2Li+(aq) + Mg(NO3)2(aq) 2LiNO3(aq) + Mg2+(aq) 3Mg2+(aq) + 2PO43–(aq) Mg3(PO4)2(aq) 2Li3PO4(aq) + 3Mg2+(aq) Mg3(PO4)2(s) + (Li+)6(aq) 2Li3PO4(aq) + 3Mg(NO3)2(aq) Mg3(PO4)2(s) + 6LiNO3(aq)
ANS: A DIF: moderate OBJ: Identify the balanced net ionic reaction given the reactants. TOP: Reactions in Aqueous Solutions 190. The formula of the perchlorate ion is a. Cl2O3–. b. ClO2–. c. Cl–. d. ClO4–. e. ClO–. ANS: D DIF: easy OBJ: Identify the polyatomic ion formula given the name. TOP: Naming Ternary Acids and Their Salts 191. What is the correct name for Ga2S3? a. b. c. d. e.
gallium(III) sulfide gallium sulfide digallium trisulfide gallium trisulfide digallium(II) sulfide
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ANS: A DIF: moderate OBJ: Identify the name of an ionic compound given the formula. TOP: Naming Binary Compounds 192. The compound ammonium iodide is a strong electrolyte. Which of the following equations
represents the transformation that occurs when ammonium iodide dissolves in water: a. NH3 I(s) NH3+(aq) + I- (aq) b. NH4I (s) NH4+(aq) + I- (aq) c. NH3I2(s) NH32+ (aq) + 2I- (aq) d. NH4I2(s) NH42+ (aq) + 2I- (aq) e. NH4I(s) N3+ (aq) + 4H+ (aq) + I- (aq) ANS: B OBJ: Identify the balanced equation for the dissolution of an electrolyte. TOP: Aqueous Solutions – An Introduction 193. When aqueous solutions of calcium iodide, CaI2, and silver nitrate, AgNO3, are combined,
which of the following statements below describes what occurs: a. A precipitate of Ca(NO3)2 forms c. Both Ca(NO3)2 and AgI precipitate b. A precipitate of AgI forms d. No precipitate will form ANS: B OBJ: Identify the product of a reaction. TOP: Reactions in Aqueous Solutions 194. When aqueous solutions of K3PO4 and (NH4)2CO3 are mixed, which of the following
statements below describes what occurs? a. A precipitate of K2CO3 forms b. A precipitate of (NH4)3PO4 forms c. Both K2CO3 and (NH4)3PO4 precipitate d. No precipitate forms ANS: D OBJ: Identify the product of a reaction. TOP: Reactions in Aqueous Solutions 195. Which of the following are paired incorrectly? a. H2C2O4 – strong acid b. NaOH – strong base c. HCH3O2 – weak acid d. HNO3 – strong acid e. NH3 – weak base ANS: A OBJ: Identify the incorrectly classified acid or base. TOP: Metathesis (Acid-Base) Reactions
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196. Which of the following is the correct net ionic equation for the reaction that occurs when
aqueous barium hydroxide and hydrochloric acid are combined? a. Ba(OH)2(aq) + 2HCl(aq) BaCl2(s) + 2H2O(l) b. Ba2+(aq) + 2OH-(aq) + 2H+(aq) + 2Cl-(aq) BaCl2(s) + 2H2O(l) c. Ba2+(aq) + 2OH-(aq) + 2H+(aq) + 2Cl-(aq) Ba2+(aq) + 2Cl-(aq) + 2H2O(l) d. 2OH-(aq) + 2H+(aq) 2H2O(l) e. H+(aq) + OH- H2O(l) ANS: E OBJ: Identify the correct acid-base net ionic reaction. TOP: Metathesis (Acid-Base) Reactions 197. Which of the following is the correct net ionic equation for the reaction that occurs when
excess nitric acid (aq) and manganese(II) carbonate (s) are combined? a. HNO3(aq) + MnCO3(s) H2O(l) + CO2(g) + Mn(NO3)2(aq) b. 2HNO3(aq) + MnCO3(s) H2O(l) + CO2(g) + MnNO3(aq) c. H+(aq) + NO3-(aq) + Mn2+(aq) + CO32-(aq) H2O(l) + CO2(g) +Mn2+(aq) + NO3(aq) d. 2H+(aq) + MnCO3(s) H2O(l) + CO2(g) + Mn2+(aq) e. 2H+(aq) + CO32-(aq) H2O(l) + CO2(l) ANS: D OBJ: Identify the correct acid-base (gas forming) net ionic reaction. TOP: Metathesis (Acid-Base) Reactions
Instructions: Use the unbalanced redox reaction below to answer the following questions: N2H4 + P + H2O PH3 + NH2OH 198. In the redox reaction above, which element is being reduced? a. N b. H c. P d. O e. This is not a redox reaction ANS: C OBJ: Identify the element undergoing reduction. TOP: Oxidation-Reduction Reactions 199. In the redox reaction above, how many electrons are being transferred? a. 1eb. 2ec. 3ed. 5ee. 6eANS: C OBJ: Determine the number of electrons transferred. TOP: Oxidation-Reduction Reactions
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200. Which of the following would you predict to be insoluble in water? a. ZnS b. NiSO4 c. Ca(C2H3O2)2 d. Na3PO4 e. FeCl3 ANS: A OBJ: Identify the insoluble compounds. TOP: Metathesis (Precipitation) Reactions 201. When aqueous solutions of MnCl2 and (NH4)2CO3 are mixed, which of the following
statements below describes what occurs? a. A precipitate of MnCO3 forms b. A precipitate of NH4Cl forms
c. Both MnCO3 and NH4Cl precipitate d. No precipitate forms
ANS: A OBJ: Identify the product of a reaction. TOP: Metathesis (Precipitation) Reactions 202. Which of the following is the balanced net ionic equation for the reaction of silver(I) nitrate
and potassium phosphate? a. 3AgNO3(aq) + K3PO4(aq) Ag3PO4(s) + 3KNO3(aq) b. 3Ag+(aq) + 3NO3-(aq) + 3K+(aq) + PO43-(aq) AgNO3(s) + 3K+(aq) + 3NO3(aq) c. 3AgNO3(aq) + K3PO4(aq) 3KNO3(s) + Ag3PO4-(aq) d. 3Ag+(aq) + 3NO3-(aq) + 3K+(aq) + PO43-(aq) 3KNO3(s) + 3Ag+(aq) + PO43(aq) e. 3Ag+(aq) + PO43-(aq) Ag3PO4(s) ANS: E OBJ: Identify the net ionic reaction. TOP: Metathesis (Precipitation) Reactions 203. Which of the following are paired incorrectly? a. HBr – strong acid b. Ca(OH)2 – strong base c. HC2H3O2 – weak acid d. HClO4 – weak acid e. NH3 – weak base ANS: D OBJ: Identify the incorrectly classified acid or base. TOP: Metathesis (Acid-Base) Reactions 204. Identify the oxidizing agent in the following reaction: a. I2 c. Ib. Zn d. Zn2+
I2 + Zn 2I- + Zn2+
ANS: A OBJ: Identify the oxidizing agent. TOP: Oxidation-Reduction Reactions Whitten 10e
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205. What is the name of the compound with the formula PI3? a. phosphorus iodide b. potassium iodide c. phosphorus(III) iodide d. potassium(III) iodide e. phosphorus triiodide ANS: E OBJ: Name the ionic compound. TOP: Naming Binary Compounds 206. What is the name of the compound with the chemical formula CF4? a. carbon fluoride b. carbon fluorate c. carbon(IV) fluoride d. carbon tetrafluoride e. monocarbon tetrafluoride ANS: D OBJ: Name the molecular compound. TOP: Naming Binary Compounds 207. What is the correct systematic name for ICl5? a. Iodine chloride b. Iodine heptachloride c. Iodine pentachloride d. Monoiodine heptachloride e. Monoiodine pentachloride ANS: C OBJ: Name the molecular compound. TOP: Naming Binary Compounds 208. Give the name of the molecular compound and the name of the aqueous solution for the a. b. c. d. e.
binary compound HF: hydrogen fluoride, fluoric acid hydrogen fluoride, hydrofluoric acid hydrogen monofluoride, hydrofluoric acid hydrogen monofluoride, fluoric acid hydrogen monofluoride, fluorous acid
ANS: C OBJ: Identify the name of the acid. TOP: Naming Ternary Acids and Their Salts 209. All of the following are in aqueous solution. Which is incorrectly named? a. H3PO4, phosphoric acid b. HCN, cyanic acid c. H2SO3, sulfurous acid d. HMnO4, permanganic acid e. HNO2, nitrous acid
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ANS: B OBJ: Identify the incorrect acid formula or name. TOP: Naming Ternary Acids and Their Salts 210. What is the name for the compound with the formula HF(aq)? a. fluoric acid b. fluorous acid c. hydrofluoric acid d. hydrofluorous acid e. hydrogen monofluoride ANS: C OBJ: Name the acid. TOP: Naming Ternary Acids and Their Salts 211. What is the name of the compound with the formula HNO2? a. Nitric acid b. Nitrous acid c. Hydronitric acid d. Hydronitrous acid e. Hydrogen mononitrogen dioxide ANS: B OBJ: Name the acid. TOP: Naming Ternary Acids and Their Salts 212. What is the chemical formula for nitric acid? a. HNO2 b. HNO3 c. HNO4 d. H2NO3 e. H2NO2 ANS: B OBJ: Match the acid formula to the name. TOP: Naming Ternary Acids and Their Salts CONCEPTUAL 1. Why are sulfuric acid molecules never found in aqueous solution? Why is Mg(OH)2 considered a weak base but Sr(OH)2 is a strong one? OBJ: Discuss the meaning of strong and weak in the context of aqueous acid and base chemistry. TOP: Aqueous Solutions – An Introduction 2. What are some reasons that Zn is more reactive than metals like Fe, Cu and Ni? OBJ: Explain the activity series of the metals. TOP: Oxidation-Reduction Reactions
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3. Why is reduction (gain of electrons) represented by a decrease in oxidation number? OBJ: Explain why reduction decreases oxidation numbers. TOP: Oxidation Numbers 4. A travel agent is a person who facilitates travel for someone else. Use this analogy to explain why an oxidizing agent is actually reduced. OBJ: Use an analogy to explain the reduction of an oxidizing agent. TOP: Oxidation-Reduction Reactions 5. Does the combination of 0.1 M NaBr and 0.1 M (NH4)2S represent a chemical reaction? Why or why not? OBJ: Explain why the reactants react or do not react. TOP: Reactions in Aqueous Solutions 6. Why is the name iron oxide ambiguous where magnesium oxide is not? Why is it important to have an organization like IUPAC if you synthesize a previously unknown compound? OBJ: Explain naming binary compounds of metal ions and the importance of a universal system of naming. TOP: Naming Binary Compounds 7. Despite the fact that they can be canceled out of a net ionic equation, spectator ions still have a function. What is this role that spectator ions play in a reaction? OBJ: Explain the role of spectator ions in a chemical reaction. TOP: Reactions in Aqueous Solutions 8. Chemical reactions are sometimes represented by general equations that don't represent any specific substances or reactions but illustrate key characteristics that are common to that type of reaction. What type of reaction might be represented by each of the following general equations: a. AB + CD AD + CB b. AB A + B c. A + BC AC + B d. A + B AB OBJ: Classify each general reaction. TOP: Summary of Reaction Types
Chapter 7—Chemical Bonding MULTIPLE CHOICE 1. Which of the following statements about ionic and covalent compounds is false? a. Electrons are shared in covalent compounds. b. Covalent compounds are usually poor conductors of electricity. c. Many ionic compounds are soluble in water. d. Covalent compounds commonly exist as gases, liquids or solids. e. Ionic compounds have low melting points.
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ANS: E OBJ: Identify the chemical and physical properties of ionic and covalent compounds. TOP: Ionic and Covalent Bonding 2. Which response includes only the true statements concerning the characteristics of covalent compounds? I. These compounds can be gases, liquids, or solids with low melting points. II. Most are soluble in polar solvents. III. Liquid and molten compounds do not conduct electricity. IV. Aqueous solutions of these compounds are very good conductors of electricity. a. b. c. d. e.
I and III II and IV I, III, and IV I, II, and III IV
ANS: A OBJ: Identify the chemical and physical properties of covalent compounds. TOP: Ionic and Covalent Bonding 3. Which Lewis Dot Formula below is incorrect? a. b. c. d. e. ANS: B OBJ: Identify the correct Lewis Dot Formulas. TOP: Lewis Dot Formulas of Atoms
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4. Which Lewis Dot Formula is incorrect? a. b. c. d. e. ANS: D OBJ: Identify the correct Lewis Dot Formulas. TOP: Lewis Dot Formulas of Atoms 5. Which Lewis Dot Formula below is incorrect? a. b. c. d. e. ANS: C DIF: Harder Question OBJ: Identify the correct Lewis Dot Formulas. TOP: Lewis Dot Formulas of Atoms 6. How many valence electrons does a phosphorus atom have? a. 2 b. 6 c. 3 d. 5 e. 4 ANS: D OBJ: Determine the number of valence electrons. TOP: Lewis Dot Formulas of Atoms 7. How many valence electrons does an iodine atom have? a. 7 b. 6 c. 3 d. 5 e. 4 ANS: A OBJ: Determine the number of valence electrons. TOP: Lewis Dot Formulas of Atoms 8. How many unpaired electrons are shown in a Lewis Dot Formula for silicon? a. 0 b. 1 c. 2 d. 3 e. 4 Whitten 10e
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ANS: C OBJ: Determine the number of unpaired electrons. TOP: Lewis Dot Formulas of Atoms 9. Below are some elements with their number of valence electrons. Which is incorrect? a. Ca / 2 b. Cl / 5 c. K / 1 d. B / 3 e. O / 6 ANS: B OBJ: Determine the number of valence electrons of each element. TOP: Lewis Dot Formulas of Atoms 10. An atom of which element below has the most unpaired electrons? a. Ba b. Al c. P d. F e. O ANS: C DIF: Harder Question OBJ: Determine the number of unpaired electrons. TOP: Lewis Dot Formulas of Atoms 11. An element has the following electronic configuration in its outermost shell. In simple ionic compounds the oxidation number of this element would be ____.
a. b. c. d. e.
1 2 3 +2 +1
ANS: D OBJ: Identify a Group I metal from its outmost electron configuration. TOP: Formation of Ionic Compounds 12. Consider the following electron transfer diagram representing the formation of a binary ionic compound from atoms of its constituent elements. Which response correctly identifies the elements?
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a. b. c. d. e.
M = Na; X = O M = Ca; X = Cl M = K; X = S M = Na; X = S M = Rb; X = O
ANS: C OBJ: Identify atoms and ions from their outmost electron configuration. TOP: Formation of Ionic Compounds 13. The negative ion F has the same electronic configuration as the positive ion ____. a. Ca2+ b. Li+ c. Mg2+ d. K+ e. Sc3+ ANS: C OBJ: Identify the isoelectronic ion. TOP: Formation of Ionic Compounds 14. What is the charge formed by alkaline earth metals when they react with nonmetals? a. +1 b. 1 c. +2 d. 2 e. +3 ANS: C OBJ: Identify the oxidation state of Group II ions. TOP: Formation of Ionic Compounds 15. Which Lewis dot notation for atoms and ions is correct for the reaction for the formation of calcium phosphide? a. b. c. d. e. ANS: E OBJ: Identify the correct Lewis Dot Formulas and reaction stoichiometry. TOP: Formation of Ionic Compounds
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16. Which Lewis dot notation for atoms and ions is correct for the reaction for the formation of aluminum oxide? a. b. c. d. e. ANS: D OBJ: Identify the correct Lewis Dot Formulas and reaction stoichiometry. TOP: Formation of Ionic Compounds 17. Which of the following statements is the best definition of valence electrons? a. The electrons in the p orbitals b. The electrons that are paired. c. The electrons occupying the highest energy (outermost) level. d. The electrons occupying the lowest energy (outermost) level. e. The electrons that are unpaired. ANS: C OBJ: Define valence electrons. TOP: Formation of Ionic Compounds 18. Which response includes all of the species listed below that have 5 valence electrons? O2, N, P, C, F a. b. c. d. e.
N, P N, P, C O2, C, F O2 P, C
ANS: B OBJ: Identify the atoms and ions with equal numbers of valence electrons. TOP: Formation of Ionic Compounds 19. Which response includes all of the species listed below that have the electronic configuration 1s22s22p63s23p6? Cl, Na+, K+, Ar, P3 a. b. c. d. e.
Cl and Na+ Cl, Na+, and Ar Na+, Ar, and P3 Na+, K+, and Ar Cl, K+, Ar, and P3
ANS: E OBJ: Identify the atoms and ions with the given electron configuration. TOP: Formation of Ionic Compounds Whitten 10e
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20. Which choice below represents the general reaction of the 1A metals with the 7A elements? a. 2M(s) + X2 2MX(s) b. M(s) + X MX(s) c. M2(s) + X2 2MX(s) d. M(s) + X2 MX2(s) e. none of these ANS: A OBJ: Identify the balanced equation given the reactants. TOP: Formation of Ionic Compounds 21. Calcium and chlorine react to form CaCl2, an ionic compound. The chloride ion, Cl, has ____ electrons in its outermost occupied shell. a. 6 b. 2 c. 8 d. 18 e. 7 ANS: C OBJ: Determine the number of valence electrons. TOP: Formation of Ionic Compounds 22. Magnesium and nitrogen react to form Mg3N2 an ionic compound. The magnesium ion, Mg2+, has ____ electrons in its highest occupied energy level. a. 8 b. 2 c. 10 d. 4 e. 5 ANS: A OBJ: Determine the number of electrons in the highest energy level. TOP: Formation of Ionic Compounds 23. Which of the following compounds has the most ionic bond? a. MgF2 b. BCl3 c. NF3 d. NaF e. NF3 ANS: D OBJ: Identify the compound with the greatest ionic character. TOP: Formation of Ionic Compounds 24. What is the charge on the simple (single atom) ion that sulfur forms? a. 1+ b. 2+ c. 3+ d. 1 e. 2
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ANS: E OBJ: Identify the oxidation state of monatomic sulfur ions. TOP: Formation of Ionic Compounds 25. What is the charge on the simple (single atom) ion that tellurium forms? a. 1+ b. 2+ c. 3+ d. 1 e. 2 ANS: E OBJ: Identify the oxidation state of monatomic tellurium ions. TOP: Formation of Ionic Compounds 26. When one mole of calcium, Ca, combines with one-half mole of oxygen, O2, to form calcium oxide, CaO, ____ mole(s) of electrons are transferred from ____ atoms to ____ atoms. a. one-half; oxygen; calcium b. one; oxygen; calcium c. one; calcium; oxygen d. two; oxygen; calcium e. two; calcium; oxygen ANS: E OBJ: Determine the number of electrons transferred given the balanced reaction. | Identify the species that lose and gain electrons. TOP: Formation of Ionic Compounds 27. Consider the formation of one formula unit of Li3N from neutral atoms. In the process, each lithium atom ____ electron(s) and each nitrogen atom ____ electron(s). a. gains three; loses one b. loses three; gains one c. loses three; gains three d. loses one; gains three e. gains one; loses three ANS: D OBJ: Determine the number of electrons transferred given the balanced reaction. | Identify the species that lose and gain electrons. TOP: Formation of Ionic Compounds 28. Consider the formation of one formula unit of AlF3 from neutral atoms. In the process, each aluminum atom ____ electron(s) and each fluorine atom ____ electron(s). a. gains three; loses one b. loses three; gains one c. loses three; gains three d. loses one; gains three e. gains one; loses three ANS: B OBJ: Identify the number of electrons lost and gained in the reaction. TOP: Formation of Ionic Compounds
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29. What is the formula for the binary compound of aluminum and nitrogen? a. Al2N2 b. Al2N c. AlN2 d. Al2N3 e. AlN ANS: E OBJ: Identify the formula of a binary compound. TOP: Formation of Ionic Compounds 30. What is the formula for the binary compound of calcium and bromine? a. CaBr b. Ca2Br c. CaB d. CaB2 e. CaBr2 ANS: E OBJ: Identify the formula of a binary compound. TOP: Formation of Ionic Compounds 31. What is the formula for the binary compound of gallium and chlorine? a. GaCl b. GaCl2 c. Ga3Cl2 d. GaCl3 e. Ga2Cl3 ANS: D OBJ: Identify the formula of a binary compound. TOP: Formation of Ionic Compounds 32. What is the formula for the binary ionic compound of lithium and nitrogen? a. LiN b. LiN2 c. Li2N d. Li3N e. Li2N3 ANS: D OBJ: Identify the formula of a binary compound. TOP: Formation of Ionic Compounds 33. The formula for the simple ionic compound of barium and nitrogen is ____. a. BaN b. Ba2N c. Ba2N3 d. BaN2 e. Ba3N2 ANS: E OBJ: Identify the formula of a binary compound. TOP: Formation of Ionic Compounds
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34. What is the formula for the binary ionic compound of aluminum and selenium? a. AlSe b. Al2Se c. AlSe2 d. Al3Se2 e. Al2Se3 ANS: E OBJ: Identify the formula of a binary compound. TOP: Formation of Ionic Compounds 35. Which one of the formulas below is incorrect? a. MgCl2 b. NaI c. InF3 d. K2S e. Sr2O ANS: E OBJ: Identify the incorrect formula of a binary compound. TOP: Formation of Ionic Compounds 36. Which one of the formulas below is incorrect? a. SrCl2 b. Cs2S c. AlBr3 d. AlP e. CaSe2 ANS: E OBJ: Identify the incorrect formula of a binary compound. TOP: Formation of Ionic Compounds 37. Which of the following formulas is incorrect? a. CaO b. K2O c. MgTe d. RbF e. Al3O2 ANS: E OBJ: Identify the incorrect formula of a binary compound. TOP: Formation of Ionic Compounds 38. Which of the following formulas is incorrect? a. MgSe b. Na2S c. RbF d. Al2N3 e. BaCl2 ANS: D OBJ: Identify the incorrect formula of a binary compound. TOP: Formation of Ionic Compounds
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39. Which of the following formulas is incorrect? a. Li3N b. Mg2O c. KI d. NaBr e. SrS ANS: B OBJ: Identify the incorrect formula of a binary compound. TOP: Formation of Ionic Compounds 40. Which of the following statements about the d-transition metal ions is false? a. The outer s electrons are always the first ones lost when transition metals form simple ions. b. Zinc forms a single positive ion, Zn2+. c. Scandium forms a single positive ion, Sc3+. d. Cobalt forms a single positive ion, Co2+. e. Most transition metals can form at least two cations in their compounds. ANS: D OBJ: Know the charges and electron configurations of the d-transition metals. TOP: Formation of Ionic Compounds 41. The ionic solid NaCl is more stable than a mixture of Na and Cl atoms. This is best explained by: a. The large, negative crystal lattice energy compensates for the energy lost when forming Na+ and Cl. b. Both the electron affinity for Cl and the ionization energy for Na are negative values. c. The negative value for the electron affinity for Cl is larger than the ionization energy required for Na. d. The negative value for the ionization energy required for Na is larger than the electron affinity for Cl. e. None of these is the correct explanation. ANS: A OBJ: Understand the factors that contribute to the stability of ionic lattices. TOP: Formation of Ionic Compounds 42. A chemical bond formed by two atoms sharing one or more pairs of electrons is called a(n) ____ bond. a. ionic b. covalent c. coordinate covalent d. polar e. nonpolar ANS: B OBJ: Define covalent bond. TOP: Formation of Covalent Bonds 43. When the diatomic molecule H2 forms, all of the following are true except: a. A pair of electrons is shared between the two hydrogen atoms. b. The 1s orbitals overlap so that both electrons are now in the orbitals of both atoms. c. Each hydrogen atom has the helium configuration 1s2. d. A single covalent bond is formed. e. The bonded atoms are at higher energy than the separated atoms.
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ANS: E OBJ: Describe the bonding in hydrogen. TOP: Formation of Covalent Bonds 44. The internuclear distance at which the attractive and repulsive forces balance in a covalent bond is called the ____. a. bond length b. bond energy c. stabilization length d. single bond e. none of these ANS: A OBJ: Define bond length. TOP: Bond Lengths and Bond Energies 45. The ____ bonds there are between atoms of the same two elements, the ____ the bond length and the ____ the bond. a. more; greater; weaker b. more; shorter; stronger c. fewer; shorter; stronger d. fewer; greater; stronger e. more; shorter; weaker ANS: B OBJ: Understand the relationship between bond order, bond length, and bond strength. TOP: Bond Lengths and Bond Energies 46. Which of the following is the correct Lewis dot formula for H2S? a.
b.
c.
d. e.
ANS: C OBJ: Identify the correct Lewis Dot Formula. TOP: Lewis Formulas for Molecules and Polyatomic Ions
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47. Which of the following is the correct Lewis dash formula for carbon diselenide? a. b. c. d. e.
ANS: B OBJ: Identify the correct Lewis Dot Formula. TOP: Lewis Formulas for Molecules and Polyatomic Ions 48. Lewis dot formulas for molecules show all of the following except: a. the number of bonds b. the kinds of bonds (single, double, triple) c. the order the atoms are connected d. the shape of the molecule e. the number of valence electrons ANS: D OBJ: Know the limits of Lewis Dot Formulas. TOP: Lewis Formulas for Molecules and Polyatomic Ions 49. Draw the Lewis dot formula for CO2. The number of unshared pairs of electrons in the outer shell of the central atom is ____. a. one b. two c. three d. four e. zero ANS: E OBJ: Draw the Lewis structure given the formula and determine the number of unshared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule 50. Draw the Lewis dot formula for PCl3. The number of unshared pairs of electrons in the outer shell of the central atom is ____. a. one b. two c. three d. four e. zero ANS: A OBJ: Draw the Lewis structure given the formula and determine the number of unshared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule
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51. The number of unshared pairs of electrons in the outer shell of sulfur in H2S is ____. a. one b. two c. three d. four e. zero ANS: B OBJ: Draw the Lewis structure given the formula and determine the number of unshared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule 52. Draw the Lewis dot formula for NH4+. How many unshared pairs of electrons are in the outer shell of the central nitrogen atom? a. 2 b. 4 c. 6 d. 8 e. 0 ANS: E OBJ: Draw the Lewis structure given the formula and determine the number of unshared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule 53. The Lewis structure for the carbonate ion, CO32, shows ____ doubles bond(s), ____ single bond(s) and ____ lone pair(s) on the central atom. a. 3; 1; 2 b. 1; 2; 0 c. 2; 2; 1 d. 2; 1; 1 e. 2; 1; 2 ANS: B OBJ: Draw the Lewis structure given the formula and identify the number of double bonds, single bonds, and lone pairs on the central atom. TOP: Writing Lewis Formulas: The Octet Rule 54. How many shared pairs of electrons are in the outer shell of the central nitrogen atom of NH3? a. 4 b. 3 c. 2 d. 1 e. 0 ANS: B OBJ: Draw the Lewis structure given the formula and determine the number of shared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule
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55. The total number of valence electrons that must be shown in the dot formula for the C4H5Cl2FO molecule is ____. (It is not necessary to draw the dot formula.) a. 42 b. 44 c. 46 d. 48 e. 50 ANS: D OBJ: Determine the total number of valence electrons. TOP: Writing Lewis Formulas: The Octet Rule 56. In applying the relationship S = N A for the PF3 molecule N = ____, A = ____, and S = ____. a. b. c. d. e.
N 34 32 30 32 30
A 26 24 22 26 24
S 8 8 8 6 6
ANS: D OBJ: Determine the number of electrons shared, needed, and available. TOP: Writing Lewis Formulas: The Octet Rule 57. When writing the relationship among N, A, and S for H2CO3, N = ____, A = ____, and S = ____. a. b. c. d. e.
N 36 36 34 40 34
A 24 26 22 16 24
S 12 10 12 14 10
ANS: A OBJ: Determine the number of electrons shared, needed, and available. TOP: Writing Lewis Formulas: The Octet Rule 58. When writing the relationship among N, A, and S for SO32, N = ____, A = ____, and S = ____. a. b. c. d. e.
N 32 26 34 32 34
A 32 32 26 26 24
S 12 6 8 6 1
ANS: D OBJ: Determine the number of electrons shared, needed, and available. TOP: Writing Lewis Formulas: The Octet Rule
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59. In constructing the dot formula for H3AsO4, N = ____, A = ____, and S = ____. a. b. c. d. e.
N 44 46 44 46 42
A 32 30 30 32 30
S 12 12 14 14 12
ANS: D OBJ: Determine the number of electrons shared, needed, and available. TOP: Writing Lewis Formulas: The Octet Rule 60. What is the correct Lewis dot formula for H2CO3? a.
b.
c.
d.
e.
ANS: C OBJ: Identify the correct Lewis Dot Formula. TOP: Writing Lewis Formulas: The Octet Rule
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61. Which one of the following Lewis dot formulas is incorrect? a.
b.
c.
d.
e. ANS: A OBJ: Identify the correct Lewis Dot Formulas. TOP: Writing Lewis Formulas: The Octet Rule 62. Which one of the following Lewis dot formulas is incorrect? a.
b.
c.
d. e. ANS: D OBJ: Identify the correct Lewis Dot Formulas. TOP: Writing Lewis Formulas: The Octet Rule
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63. Which Lewis dot formula is incorrect? a.
b.
c. d.
e.
ANS: D OBJ: Identify the correct Lewis Dot Formulas. TOP: Writing Lewis Formulas: The Octet Rule 64. The total number of covalent bonds in the N2 molecule is ____. a. one b. two c. three d. four e. zero ANS: C OBJ: Draw the Lewis Dot Formula and determine the number of covalent bonds. TOP: Writing Lewis Formulas: The Octet Rule 65. The number of unshared pairs of electrons in the outer shell of oxygen in Cl2O is ____. a. one b. two c. three d. four e. zero ANS: B OBJ: Draw the Lewis structure given the formula and determine the number of unshared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule
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66. The number of unshared pairs of electrons in the outer shell of arsenic in AsF5 is ____. a. one b. two c. three d. four e. zero ANS: E OBJ: Draw the Lewis structure given the formula and determine the number of unshared outer shell electrons on the central atom. TOP: Writing Lewis Formulas: The Octet Rule 67. Draw the dot formula for ethylene, C2H4. Each carbonhydrogen bond is a ____ bond and each carboncarbon bond is a ____ bond. a. single; single b. single; double c. single; triple d. double; single e. double; double ANS: B OBJ: Draw the Lewis structure given the formula and identify the covalent bonds. TOP: Writing Lewis Formulas: The Octet Rule 68. Draw the dot formula for acetylene, C2H2. The two carbon atoms are bonded together and each carbon is bonded to one hydrogen. Each carbonhydrogen bond is a ____ bond and each carboncarbon bond is a ____ bond. a. single; single b. single; double c. single; triple d. double; single e. double; double ANS: C OBJ: Draw the Lewis structure given the formula and identify the covalent bonds. TOP: Writing Lewis Formulas: The Octet Rule 69. Draw the dot formula for N2H4. The two nitrogen atoms are bonded together and each nitrogen is bonded to two hydrogen atoms. Each nitrogenhydrogen bond is a ____ bond and the nitrogennitrogen bond is a ____ bond. a. single; single b. single; double c. single; triple d. double; single e. double; double ANS: A OBJ: Draw the Lewis structure given the formula and identify the covalent bonds. TOP: Writing Lewis Formulas: The Octet Rule
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70. The Lewis dot formula for N2 shows a. a single covalent bond. b. a double covalent bond. c. a triple covalent bond. d. a single ionic bond. e. a total of 8 2 = 16 electrons. ANS: C OBJ: Draw the Lewis structure given the formula and identify the covalent bonds. TOP: Writing Lewis Formulas: The Octet Rule 71. The Lewis dot formula for CO2 shows a. two single covalent bonds. b. one single covalent bond and one double covalent bond. c. one single covalent bond and one triple covalent bond. d. a total of 8 3 = 24 electrons (dots). e. two double covalent bonds. ANS: E OBJ: Draw the Lewis structure given the formula and identify the covalent bonds. TOP: Writing Lewis Formulas: The Octet Rule 72. Which of the following is NOT shown in the Lewis structure for NH2? a. A total of 8 valence electrons are represented. b. Two single bonds are shown c. One lone pair is on each H atom. d. Two lone pairs are shown on the central atom. e. A total of 4 shared electrons are shown. ANS: C OBJ: Draw the Lewis structure given the formula and identify the covalent bonds and the number of shared, unshared, and available electrons. TOP: Writing Lewis Formulas: The Octet Rule 73. The Lewis dot formula for formaldehyde, H2CO, shows I. three single covalent bonds. II. one unshared pair of electrons. III. one double covalent bond. IV. two unshared pairs of electrons. V. two single covalent bonds. a. b. c. d. e.
III, IV and V II, III and V I and II II and III I and IV
ANS: A OBJ: Draw the Lewis structure given the formula and identify the covalent bonds and the number of shared, unshared, and available electrons. TOP: Writing Lewis Formulas: The Octet Rule
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74. Which of the following guidelines for drawing Lewis formulas for covalent compounds is incorrect? a. Carbon always forms 4 bonds. b. Hydrogen can never be a central atom. c. Representative elements (except hydrogen) usually follow the octet rule. d. In neutral species, nitrogen forms 3 bonds and oxygen forms 2 bonds. e. One carbon atom in a compound may form both a double bond and a triple bond. ANS: E OBJ: Identify the guidelines for drawing valid Lewis Dot Formulas. TOP: Writing Lewis Formulas: The Octet Rule 75. Assign a formal charge to each atom of
a. b. c. d. e.
As = 5+; Cl = 1 As = 5; Cl = 7+ As = 0; Cl = 0 As = 3+; Cl = 1 As = 6+; Cl = 2
ANS: C OBJ: Assign formal charges given the Lewis structure. TOP: Formal Charge 76. Assign a formal charge to each atom of PH4+. a. P = 0; H = 1+ b. P = 1+; H = 0 c. P = 0; H = 0 d. P = 4+; H = 1 e. P = 0; H = + ANS: B OBJ: Assign formal charges given the formula. TOP: Formal Charge 77. Assign a formal charge to each atom of
a. b. c. d. e.
Cl = 1; O = 0 Cl = 0; O = 0 Cl = 0; O = 1 Cl = 2+; O = 1 Cl = 2; O = 1
ANS: D OBJ: Assign formal charges given the Lewis structure. TOP: Formal Charge
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78. Which of the following statements about Lewis structures is false? a. Carbon and oxygen may form a double bond. b. Any Noble gas involved in a bond must be violating the octet rule. c. N, P and As can sometimes share more than 8 e. d. H can never make more than one bond. e. Quadruple bonds are not possible. ANS: C OBJ: Know the limits and exceptions to the octet rule. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 79. Which one of the following dot formulas is incorrect? a.
b.
c. d.
e.
ANS: D OBJ: Identify the correct Lewis Dot Formulas. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 80. Which response lists all of the correct Lewis dot formulas and no incorrect ones? I.
II.
III.
IV.
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a. b. c. d. e.
I and II II, III, and IV III and IV II and III I, II, and III
ANS: A OBJ: Identify the correct Lewis Dot Formulas. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 81. How many lone pairs of electrons are there on the Xe atom in the XeF4 molecule? a. one b. two c. three d. four e. zero ANS: B OBJ: Draw the Lewis structure given the formula and determine the number of unshared electrons on the central atom. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 82. How many lone pairs of electrons are there on the S atom in the SCl4 molecule? a. one b. two c. three d. four e. zero ANS: A OBJ: Draw the Lewis structure given the formula and determine the number of unshared electrons on the central atom. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 83. Which molecule below has only one unshared pair of electrons in the valence shell of the central atom? a. H2S b. HF c. PH3 d. BCl3 e. BeCl2 ANS: C OBJ: Draw the Lewis structure given the formula and determine the number of unshared electrons on the central atom. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas
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84. Which of the responses includes all of the following molecules that have no unshared pairs of electrons about the central atom, and no other molecules? BCl3, AsF5, NF3, H2S a. b. c. d. e.
BCl3 and AsF5 AsF5, NF3, and H2S NF3 and H2S BCl3 and H2S BCl3 and NF3
ANS: A OBJ: Draw the Lewis structures given the formulas and determine the number of unshared electrons on the central atoms. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 85. Which response lists all the molecules below that have one unshared pair of electrons on the central atom, and no other molecules? H2O, NF3, BF3, OF2 a. b. c. d. e.
H2O NF3 NF3 and OF2 H2O, NF3, and OF2 H2O and NF3
ANS: B OBJ: Draw the Lewis structures given the formulas and determine the number of unshared electrons on the central atoms. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 86. Which of the following molecules cannot exist? a. PI5 b. BeF2 c. SF2 d. CF3 e. N2O ANS: D OBJ: Identify the incorrect formula of a binary compound. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 87. Which one of the following molecules violates the octet rule? a. PCl3 b. CBr4 c. NF3 d. OF2 e. AsF5 ANS: E OBJ: Identify the molecule whose Lewis structure violates the octet rule. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas
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88. Which one of the following violates the octet rule? a. PCl4+ b. ClF c. CCl3 d. BCl3 e. AsCl3 ANS: D OBJ: Identify the molecule or polyatomic ion whose Lewis structure violates the octet rule. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 89. Which of the following compounds is a Lewis Acid? a. SF6 b. BF3 c. CF4 d. NF3 e. none of these ANS: B OBJ: Identify the Lewis acid. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 90. Which response contains all the molecules below that violate the octet rule, and no others? SF4, SiCl4, H2Te, AsF5, BeI2 a. b. c. d. e.
SF4, AsF5, BeI2 BeI2 H2Te, BeI2 SF4, SiCl4 AsF5
ANS: A OBJ: Identify the molecules with Lewis structures that violate the octet rule. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 91. Which response includes all the molecules below that violate the octet rule and only those? H2O, SF6, NF3, BeCl2 a. b. c. d. e.
H2O and SF6 SF6, NF3, and BeCl2 H2O and NF3 SF6 SF6 and BeCl2
ANS: E OBJ: Identify the molecules with Lewis structures that violate the octet rule. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 92. Which molecule exhibits resonance? a. BeI2 b. O3 c. H2S d. PCl3 e. CO2
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ANS: B OBJ: Identify the molecule with more than one valid Lewis structure. TOP: Resonance 93. Which numbered response lists all the molecules below that exhibit resonance and none that do not? I. PF5 II. HNO3 III. SO2 IV. H2O a. b. c. d. e.
I and II II and III III and IV I and III II, III, and IV
ANS: B OBJ: Identify the molecules with more than one valid Lewis structure. TOP: Resonance 94. How many resonance structures does the nitrate ion, NO3, have? a. 1 b. 2 c. 3 d. 4 e. 0 ANS: C OBJ: Determine the number of valid Lewis structures given the formula. TOP: Resonance 95. How many resonance structures does the bicarbonate ion, HCO3, have? a. 1 b. 2 c. 3 d. 4 e. 0 ANS: B OBJ: Determine the number of valid Lewis structures given the formula. TOP: Resonance 96. How many resonance structures does O3 have? a. 1 b. 2 c. 3 d. 4 e. 0 ANS: B OBJ: Determine the number of valid Lewis structures given the formula. TOP: Resonance
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97. Which of the responses lists only the molecules below that have polar covalent bonds? HI, I2, S8, KCl a. b. c. d. e.
HI and KCl I2 S8 I2 and KCl HI
ANS: E OBJ: Identify the molecules with polar covalent bonds. TOP: Polar and Nonpolar Covalent Bonds 98. Which response includes all of the following molecules that contain polar covalent bonds, and no others? NO2, PCl3, N2, H2O, P4, NH3 a. b. c. d. e.
NO2, P4, and NH3 PCl3, N2, and H2O H2O and NH3 NO2, PCl3, and H2O NO2, PCl3, H2O, and NH3
ANS: E OBJ: Identify the molecules with polar covalent bonds. TOP: Polar and Nonpolar Covalent Bonds 99. Which of the following molecules has nonpolar covalent bonds? a. NaF b. H2O c. P4 d. NH3 e. BeCl2 ANS: C OBJ: Identify the molecule with nonpolar covalent bonds TOP: Polar and Nonpolar Covalent Bonds 100. Which response includes all of the molecules that have nonpolar bonds, and no others? Cl2, BeCl2, I2, BrCl, BCl3 a. b. c. d. e.
Cl2, BeCl2, and I2 Cl2 and I2 Cl2, BeCl2, and BrCl BeCl2 and BCl3 BrCl
ANS: B OBJ: Identify the molecules with nonpolar covalent bonds TOP: Polar and Nonpolar Covalent Bonds
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101. Which molecule has the most polar covalent bond? a. HBr b. HF c. HI d. H2 e. HCl ANS: B OBJ: Identify the most polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 102. Which molecule has the most polar covalent bond? a. IBr b. HCl c. N2 d. H2 e. PH3 ANS: B OBJ: Identify the most polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 103. Which molecule has the least polar covalent bond? a. HBr b. HF c. HI d. Br2 e. HCl ANS: D OBJ: Identify the least polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 104. The elements of Group VIIA may react with each other to form covalent compounds. Which of the following single covalent bonds in such compounds is the most polar bond? (The electronegativities of the first four Group VIIA elements are: F = 4.0, Cl = 3.0, Br = 2.8, I = 2.5) a. FF b. FCl c. FBr d. FI e. ClI ANS: D OBJ: Identify the most polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 105. Which one of the compounds below has the bonds that are the most polar? (Electronegativities: H = 2.1, S = 2.5, P = 2.1, As = 2.1, Cl = 3.0, Si = 1.8, Sb = 1.9) a. H2S b. PH3 c. AsCl3 d. SiH4 e. SbCl3
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ANS: E OBJ: Identify the most polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 106. Which molecule contains the least polar bonds? (Electronegativities: H = 2.1, C = 2.5, F = 4.0, Cl = 3.0, Br = 2.8, I = 2.5) a. CF4 b. CCl4 c. CBr4 d. CI4 e. CH4 ANS: D OBJ: Identify the least polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 107. Which of the following molecules has the least polar bonds? a. BrI b. HI c. H2O d. HF e. NH3 ANS: A OBJ: Identify the least polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 108. Which one of the following molecules contains bonds that are the most polar? (Electronegativities: H = 2.1, Be = 1.5, B = 2.0, N = 3.0, F = 4.0, S = 2.5, Br = 2.8, I = 2.5) a. SF6 b. BI3 c. BeBr2 d. NH3 e. NF3 ANS: A OBJ: Identify the most polar covalent bond. TOP: Polar and Nonpolar Covalent Bonds 109. Which statement concerning dipole moments is incorrect? a. Molecular geometry affects the dipole moment of a molecule. b. The presence of lone pairs of electrons affect the dipole moment of a molecule. c. Generally, as electronegativity differences increase in diatomic molecules, the dipole moments increase. d. The dipole moment equals the product of charge and distance of separation of the charges. e. By careful experimentation, a scientist can measure the dipole moment for each individual bond of a complex molecule. ANS: E OBJ: Understand the correlation between dipole moment and Lewis structure and the origin of dipole moments. TOP: Dipole Moments
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110. Which one of the following molecules has a dipole moment? a. Cl2 b. H2 c. I2 d. BrCl e. N2 ANS: D OBJ: Identify the molecule with a dipole moment. TOP: Dipole Moments 111. Which one of the following molecules does not have a dipole moment? a. BrCl b. ClF c. BrF d. O2 e. ICl ANS: D OBJ: Identify the molecules with a dipole moment. TOP: Dipole Moments 112. Which one of the following molecules does not have a dipole moment? a. IBr b. NO c. HF d. P4 e. IF ANS: D OBJ: Identify the molecules with a dipole moment. TOP: Dipole Moments 113. Which molecule would have the strongest dipole moment? a. HBr b. HF c. HI d. H2 e. HCl ANS: B OBJ: Identify the molecule with the largest dipole moment. TOP: Dipole Moments 114. Which molecule would have the weakest dipole moment? a. HBr b. HF c. HI d. H2 e. HCl ANS: D OBJ: Identify the molecule with the weakest dipole moment. TOP: Dipole Moments
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115. Which one of the following compounds involves both ionic and covalent bonding? a. Cl2 b. Na2SO4 c. KCl d. HF e. HCN ANS: B OBJ: Identify the compound with both ionic and covalent bonds. TOP: The Continuous Range of Bonding Types 116. Which one of the following compounds contains both ionic and covalent bonding? a. HCl b. KNO3 c. MgO d. CaCl2 e. Rb3N ANS: B OBJ: Identify the compound with both ionic and covalent bonds. TOP: The Continuous Range of Bonding Types 117. Which of the following molecules has the most covalent bond character? a. NH3 b. IBr c. IF d. NaF e. PbO ANS: B OBJ: Identify the molecule with the greatest covalent character. TOP: The Continuous Range of Bonding Types 118. Which of the following molecules has the most ionic bond character? a. NCl3 b. F2 c. HF d. ClF e. HCl ANS: C OBJ: Identify the molecule with the greater ionic character. TOP: The Continuous Range of Bonding Types 119. Which of the following compounds does not contain both ionic and covalent bonding? a. Na2SO4 b. NH4NO3 c. NH4Cl d. KCl e. KClO4 ANS: D OBJ: Identify the compounds with both ionic and covalent bonds. TOP: The Continuous Range of Bonding Types
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120. Which of the following compounds does not contain both ionic and covalent bonding? a. NaNO3 b. BaSO4 c. CBr4 d. NaClO3 e. NH4Br ANS: C OBJ: Identify the compounds with both ionic and covalent bonds. TOP: The Continuous Range of Bonding Types 121. The following representation of an atom is called
a. b. c. d. e.
a Lewis dot structure. an ion. a structural formula. an electrostatic potential map. an ionic bond.
ANS: A DIF: easy OBJ: Recognize a Lewis dot formula. TOP: Lewis Dot Formulas of Atoms 122. Which of the following is the Lewis dot structure for the potassium ion? a.
b.
c.
d.
e.
ANS: E DIF: easy OBJ: Identify the ion Lewis dot formula given ion name. TOP: Lewis Dot Formulas of Atoms
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123. How many valence electrons does a chlorine atom have? a. 3 b. 4 c. 8 d. 7 e. 1 ANS: D OBJ: Determine the number of valence electrons. TOP: Lewis Dot Formulas of Atoms 124. How many unpaired electrons are shown in the Lewis dot formula of an aluminum atom? a. 2 b. 0 c. 3 d. 1 e. 5 ANS: D OBJ: Determine the number of unpaired valence electrons. TOP: Lewis Dot Formulas of Atoms 2+
125. How many unpaired electrons would be shown in the Lewis dot formula of Mg ? a. 0 b. 1 c. 2 d. 3 e. 2 ANS: A OBJ: Determine the number of unpaired valence electrons. TOP: Lewis Dot Formulas of Atoms 126. How many valence electrons are present in the Lewis dot formula of the chlorate ion, ClO3-? a. 32 b. 24 c. 30 d. 26 e. 28 ANS: D OBJ: Determine the total number of valence electrons given the polyatomic ion formula. TOP: Lewis Dot Formulas of Atoms 127. What is the formal charge of N?
a. b. c. d. e.
+1 -1 0 +2 -2
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ANS: C OBJ: Determine the formal charge of the specified atom. TOP: Lewis Dot Formulas of Atoms 128. How many valence electrons are present in the Lewis dot formula of perchloric acid? a. 32 b. 33 c. 34 d. 30 e. 36 ANS: A OBJ: Determine the total number of valence electrons given the name of the molecule. TOP: Lewis Formulas for Molecules and Polyatomic Ions 129. The Lewis structure of which of the following formula violates the octet rule? a. ClF3 b. PF3 c. OF2 d. HF e. SiF4 ANS: A OBJ: Determine the formula whose Lewis structure violates the octet rule. TOP: Lewis Formulas for Molecules and Polyatomic Ions 130. TIn the Lewis structure of BrF5, how many lone pairs are around the central atom? a. 1 b. 2 c. 3 d. 4 e. 0 ANS: A OBJ: Determine the number of lone pairs around the central atom, given the formula. TOP: Lewis Formulas for Molecules and Polyatomic Ions 131. The following Lewis structure represents the valence electron configuration of a main-group
element:
If this element is in period 2, its electron configuration is: a. 1s22s5 b. 1s22p5 c. 1s22s22p1 d. 1s22s22p3
e. 1s22s12p4
ANS: D OBJ: Match the Lewis Dot formula with an electron configuration. TOP: Lewis Dot Formulas of Atoms
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132. The following Lewis structure represents the valence electron configuration of a main-group
element:
If the element is in period 4, the symbol for the element is: a. Ga b. In c. Sc d. Y
e. Ac
ANS: A OBJ: Match the an element to the Lewis Dot structure. TOP: Lewis Dot Formulas of Atoms 133. Which of the following is the correct Lewis structure for the electron configuration
1s22s22p63s23p64s23d104p65s24d105p66s2 a.
b.
c.
d.
e.
ANS: A OBJ: Match the Lewis Dot formula to the electron configuration. TOP: Lewis Dot Formulas of Atoms 134. When you draw the Lewis structure for H2O, how many single bonds, double bonds, and lone
pair electrons reside on the central oxygen atom? a. 1 single bond, 0 double bonds, 0 lone pairs b. 1 single bond, 0 double bonds, 1 lone pair c. 1 single bond, 0 double bonds, 2 lone pairs d. 2 single bonds, 0 double bonds, 1 lone pair e. 2 single bonds, 0 double bonds, 2 lone pairs ANS: E OBJ: Determine the Lewis structure. TOP: Lewis Formulas for Molecules and Polyatomic Ions 135. When you draw the Lewis structure for PF2Cl3, how many single bonds, double bonds, and
lone pair electrons reside on the central phosphorus atom? a. 5 single bonds, 0 double bonds, 0 lone pairs b. 4 single bonds, 1 double bond, 0 lone pairs c. 5 single bonds, 0 double bonds, 1 lone pair d. 4 single bonds, 1 double bond, 1 lone pair e. 3 single bonds, 2 double bonds, 0 lone pairs ANS: A OBJ: Determine the Lewis structure. TOP: Lewis Formulas for Molecules and Polyatomic Ions 136. When you draw a Lewis structure for CH3OCH2CH3, what is the total number of lone pair
electrons? a. 0
b. 1
c. 2
d. 3
e. 4
ANS: C OBJ: Determine the Lewis structure and number of lone pairs of electrons. TOP: Lewis Formulas for Molecules and Polyatomic Ions
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137. When you draw a Lewis structure for CH3OCH2CH3, what is the total number of C-C single
bonds? a. 0
b. 1
c. 2
d. 3
e. 4
ANS: B OBJ: Determine the Lewis structure and the number of C-C bonds. TOP: Lewis Formulas for Molecules and Polyatomic Ions 138. Which of the following species has the shortest carbon-nitrogen bond? a. CH3CN b. CH3N2 c. CH2NH d. CH3CONH2 e. NO3ANS: A OBJ: Identify the molecule with the shortest bond. TOP: Bond Lengths and Bond Energies 139. Which of the following species has the strongest carbon-carbon bond? a. CH3CH3 b. CH2CH2 c. CHCH d. CH3CO2H e. CH3CHO ANS: C OBJ: Identify the molecule with the strongest bond. TOP: Bond Lengths and Bond Energies 140. Which of the following species has the weakest C-O bonds? a. CO32b. CH3CHO c. CH3OH d. CH2O e. CO2 ANS: C OBJ: Identify the molecule with the longest bond. TOP: Bond Lengths and Bond Energies 141. Based on periodic trends, which of the following covalent bonds shows the correct partial
charge distribution? a. - I-F + b. - F-Cl + c. - Si-P + d. + Cl-P + e. + S-Se + ANS: B OBJ: Identify the correct partial charge distribution. TOP: Dipole Moments Whitten 10e
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142. Based on the Lewis structure for SiF5- given below, what is the formal charge on the central
silicon atom?
a. 0
b. +1
c. -1
d. +2
e. -2
143. What is the formal charge on the nitrogen in NO2Cl? a. 0 b. +1 c. -1 d. +2
e. -2
ANS: C OBJ: Calculate the formal charge. TOP: Formal Charge
ANS: B OBJ: Calculate the formal charge. TOP: Formal Charge 144. Three non-equivalent Lewis structures for carbonyl sulfide, SCO, are given below. Use the
concepts of formal charge and electronegativity to choose the structure that is the best representation.
A
B
C
a. b. c. d.
Structure A, because all the formal charges equal 0 Structure B, because all the formal charges equal 0 Structure C, because all the formal charges equal 0 Structure A, because the negative formal charge resides on the most electronegative atom e. Structure C, because the negative formal charge resides on the most electronegative atom ANS: B OBJ: Identify the most important resonance form. TOP: Formal Charge | Resonance 145. A molecule will always be polar if it _______. a. has polar bonds b. contains both carbon and chlorine c. consists of more than three atoms d. is diatomic with different electronegativities e. ontains atoms with different electronegativities ANS: D OBJ: Odentify molecules that are always polar. TOP: Dipole Moments Whitten 10e
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CONCEPTUAL 1. Why are d orbital electrons usually not shown in Lewis dot formulas? OBJ: Explain the limitations of Lewis formulas with respect to d-orbital electrons. TOP: Lewis Dot Formulas of Atoms | Lewis Formulas for Molecules and Polyatomic Ions 2. Why must atomic orbitals overlap to form a covalent bond? What prevents the orbitals from overlapping completely? OBJ: Explain orbital overlap with respect to bond formation. TOP: Formation of Covalent Bonds 3. Why must a compound have at least one double bond to have resonance structures? Why do none of the resonance structures actually represent the real molecule? OBJ: Explain the limitations of resonance with respect to multiple bonding. TOP: Resonance 4. Suppose on Planet X three electrons can occupy each orbital and there are 4 p orbitals instead of 3. How would this change the "octet" rule? OBJ: Imagine a world in which the octet rule is not the same as this world. TOP: Writing Lewis Formulas: The Octet Rule 5. Explain why boron is considered electron deficient and how this makes it impossible to complete an octet. OBJ: Explain what is meant by electron deficient and how it effects Lewis structures. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 6. Comment on the validity of the following statement: Any noble gas atom involved in a bond must violate the octet rule. OBJ: Explore the limits of the octet rule in noble gas compounds. TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 7. How is a formal charge different than a charge on an ion? OBJ: Compare and contrast the calculation of formal charge and oxidation state. TOP: Formal Charge
Chapter 8—Molecular Structure and Covalent Bonding Theories MULTIPLE CHOICE 1. The electrons in the outer shell of an atom are involved in bonding. Another name for the outer shell is ____. a. valence shell b. bonding shell c. hybridized shell d. VSEPR shell e. Lewis shell Whitten 10e
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ANS: A OBJ: Define valence shell. TOP: Valence Electrons 2. The valence shell is a. the highest energy level occupied by electrons. b. the set of orbitals used to make triple bonds. c. the orbitals belonging to the entire molecule. d. the lowest energy level occupied by electrons. e. the hard covering on crustaceans. ANS: A OBJ: Define valence shell. TOP: Valence Electrons 3. What is the electronic geometry for 6 regions of high electron density on a central atom? a. octahedral b. square planar c. tetrahedral d. trigonal bipyramidal e. trigonal planar ANS: A OBJ: Identify the electron geometry given the number of electron groups surrounding the central atom. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 4. Which of the following do not count as regions of high electron density with respect to the central atom in a molecule? a. single bonds b. lone pairs on an outer atom c. lone pairs on the central atom d. double bonds e. triple bonds ANS: B OBJ: Identify electron groups which define the electron geometry around the central atom. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory
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5. The electronic geometry is a. the arrangement of atoms around the central atom in a molecule. b. the arrangement of H atoms around the central atom in a molecule. c. the arrangement of regions of high electron density around the central atom in a molecule. d. the arrangement of lone pairs around the central atom in a molecule. e. the sets of quantum numbers for a central atom. ANS: C OBJ: Define electron geometry. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 6. What is the electronic geometry for 3 regions of high electron density on a central atom? a. octahedral b. square planar c. trigonal bipyramidal d. tetrahedral e. trigonal planar ANS: E OBJ: Identify the electron geometry given the number of electron groups surrounding the central atom. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 7. What angle(s) are associated with a central atom that has trigonal bipyramidal electronic geometry? a. 109.5 b. 120 c. 120 and 180 d. 90 and 120 e. 90 and 180 ANS: D OBJ: Identify the angles between electron groups given the electron geometry. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 8. What angle(s) are associated with a central atom that has tetrahedral electronic geometry? a. 109.5 b. 120 c. 120 and 180 d. 90 and 120 e. 90 and 180 ANS: A OBJ: Identify the angles between electron groups given the electron geometry. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 9. The phosphorus pentachloride molecule is nonpolar and contains no lone (unshared) electron pairs on the phosphorus atom. What are all of the possible ClPCl bond angles? a. 120 b. 180 c. 109.5 d. 90, 120, and 180 e. 90 and 180
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ANS: D OBJ: Identify the angles between electron groups given the molecule name, polarity, and number of lone pairs on the central atom. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 10. Which of the following is not one of the basic ideas of the VSEPR theory? a. Each electron group in the valence shell of a central atom is significant. b. The groups of valence shell electrons on the central atom repel one another. c. The groups of valence shell electrons are arranged about the central atom so that the repulsions among them are as small as possible. d. The electron groups have maximum separation about the central atom. e. The number of electron groups is determined by counting the number of lone pairs and the total number of bonds. ANS: E OBJ: Identify the tenets of VSEPR theory. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 11. Which of the following statements concerning polar molecules is false? a. There must be at least one polar bond or one unshared pair of electrons on the central atom. b. If there are more than one polar bond, they must not be symmetrically arranged so that their polarities cancel. c. If there are more than one unshared pair of electrons on the central atom, they must not be symmetrically arranged so that their polarities cancel. d. There must be an odd number of polar bonds so that their polarities not cancel. e. A molecule with symmetrically arranged polar bonds can be polar if the central atom is bonded to atoms of different elements. ANS: D OBJ: Identify the factors that give polar or nonpolar molecules. TOP: Polar Molecules: The Influence of Molecular Geometry 12. Which one of the following molecules is polar? a. N2 b. P4 c. Cl2 d. CO2 e. H2O ANS: E OBJ: Identify the polar molecule. TOP: Polar Molecules: The Influence of Molecular Geometry 13. Which one of the following molecules is nonpolar? a. H2O b. CO2 c. CSO d. NF3 e. NH3 ANS: B OBJ: Identify the nonpolar molecule. TOP: Polar Molecules: The Influence of Molecular Geometry
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14. CH4 is a nonpolar molecule. Which of the following similar molecules is also nonpolar? a. CH3Cl b. CH2Cl2 c. SiH3Cl d. SiH4 e. SiH2Cl2 ANS: D OBJ: Identify the nonpolar molecule. TOP: Polar Molecules: The Influence of Molecular Geometry 15. Draw the dot formula for the HNO2 molecule. The nitrogen atom is the central atom and the hydrogen atom is attached to an oxygen atom. On the basis of the number of regions of high electron density about the nitrogen atom, predict the nitrogen atom hybridization. a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: B OBJ: Determine the central atom hybridization given the formula. TOP: Valence Bond (VB) Theory 16. Draw the dot formula for the HNO2 molecule. The nitrogen atom is the central atom and the hydrogen atom is attached to an oxygen atom. On the basis of the number of regions of high electron density about the nitrogen atom, what is (are) the approximate bond angle(s) about the N atom? a. 180 b. 90 c. 120 d. 120 and 90 e. 109 ANS: C OBJ: Determine the central atom hybridization given the formula. TOP: Valence Bond (VB) Theory 17. Which one of the following statements about compounds or polyatomic ions of the A group elements is false? a. All compounds in which the central atom is sp3d2 hybridized violate the octet rule. b. Sulfur hexafluoride is an example of a compound with a central atom that has sp3d2 hybridization. c. All molecules in which the central element is sp3d2 hybridized have octahedral electronic geometry. d. All molecules in which the central element is sp3d2 hybridized have octahedral molecular geometry. e. All ions in which the central atom is sp3d2 hybridized have octahedral electronic geometry. ANS: D DIF: Harder Question OBJ: Understand the connection between valence bond theory and VSEPR theory. TOP: Valence Bond (VB) Theory
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18. Which of the following statements about the valence bond theory is false? a. For an atom to share more than 8 electrons it must hybridize d orbitals. b. To make 4 single bonds, an atom will make 4 sp3 hybrid orbitals. c. The number of hybrid orbitals formed equals the number of high electron density regions. d. Trigonal planar molecules use sp2 hybrid orbitals e. Atoms that do not complete their octet use either sp3d or sp3d2 hybrid orbitals. ANS: E OBJ: Understand the connection between valence bond theory and VSEPR theory. TOP: Valence Bond (VB) Theory 19. Which response contains all the following statements that are true, and no others? I. A set of sp2 orbitals can be thought of as one s orbital one-third of the time and two p orbitals two-thirds of the time. II. A set of sp orbitals can accommodate a maximum of six electrons. III. The orbitals resulting from sp3d2 hybridization are directed toward the corners of an octahedron. IV. A set of sp3 orbitals results from the mixing of one s orbital and three p orbitals. a. b. c. d. e.
II and IV I, II, and IV II, III, and IV III and IV all are true
ANS: D OBJ: Understand the connection between valence bond theory and VSEPR theory. TOP: Valence Bond (VB) Theory 20. The hybridization associated with the central atom of a molecule in which all the bond angles are 180 is ____. a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: A OBJ: Identify the central atom hybridization given the bond angles. TOP: Valence Bond (VB) Theory 21. The hybridization associated with the central atom of a molecule in which all the bond angles are 109.5 is ____. a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the bond angles. TOP: Valence Bond (VB) Theory
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22. The bond angle(s) associated with sp3d2 hybridization is (are) ____. a. 90 and 180 b. 120 c. 109 d. 90 and 120 e. 109 and 120 ANS: A OBJ: Identify the bond angles given the central atom hybridization. TOP: Valence Bond (VB) Theory 23. The central atom in a molecule is bonded to 3 other atoms and has 2 lone pairs. What type of hybrid orbitals are formed by the central atom? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: D OBJ: Identify the central atom hybridization given the number of atoms and lone pairs attached to the central atom. TOP: Valence Bond (VB) Theory 24. The central atom in a molecule is sharing a total of 12 electrons. What type of hybrid orbitals are formed by the central atom? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: E OBJ: Identify the central atom hybridization given the number electrons shared by the central atom. TOP: Valence Bond (VB) Theory 25. The central atom in a molecule has three regions of high electron density. What type of hybrid orbitals are formed by the central atom? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: B OBJ: Identify the central atom hybridization given the number of electron groups around the central atom. TOP: Valence Bond (VB) Theory
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26. The ONO bond angles associated with the nitrate ion, NO3, are all 120. The hybridization at the nitrogen atom is ____. a. sp2 b. sp3 c. sp3d2 d. sp e. sp3d ANS: A OBJ: Identify the central atom hybridization given the bond angles around the central atom. TOP: Valence Bond (VB) Theory 27. Which of the following statements about polar molecules is false? a. A molecule with polar bonds can be nonpolar. b. A molecule with polar bonds can be polar. c. A molecule with only nonpolar bonds can be polar. d. A molecule with 120 bond angles can be polar. e. A molecule with 180 bond angles can be polar. ANS: C OBJ: Understand the connection between molecular geometry, polar bonds, and polarity of a molecule. TOP: Valence Bond (VB) Theory 28. Consider the BeCl2 molecule. Which statement about this molecule is false? a. The molecule is linear. b. The molecule has polar bonds. c. The molecule is polar. d. The central atom is sp hybridized. e. Be does not satisfy the octet rule. ANS: C OBJ: Apply VSEPR and VB theory given the formula. TOP: Linear Electronic Geometry: AB2 Species 29. Which one of the following molecules has sp hybridization at the central atom? a. BeF2 b. SeF6 c. BF3 d. PF5 e. CF4 ANS: A OBJ: Identify the formula consistent with the given central atom hybridization. TOP: Linear Electronic Geometry: AB2 Species 30. What is (are) the bond angle(s) in BeI2 molecules? a. 120 b. 180 c. 90 and 180 d. 120 and 90 e. 109
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ANS: B OBJ: Determine the molecule bond angles given the formula. TOP: Linear Electronic Geometry: AB2 Species 31. Cadmium iodide, CdI2, is a covalent compound. The molecule has the same geometry as a BeCl2 molecule. Which of the following kinds of hybrid orbitals does the cadmium atom likely utilize in CdI2? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: A OBJ: Determine the central atom hybridization given the formula. TOP: Linear Electronic Geometry: AB2 Species 32. Which of the following statements concerning HgI2 (a covalent compound) is false? a. HgI2 is a linear molecule. b. The hybridization of the central Hg atom is sp. c. The electronegativity difference between Hg and I is so large that HgI2 is an ionic compound. d. Because the bond angle is 180, the two bond dipoles cancel to give a nonpolar molecule. e. The Hg atom in HgI2 does not satisfy the octet rule. ANS: C OBJ: Apply VSEPR and VB theory given the formula. | Understand the difference between ionic and covalent. TOP: Linear Electronic Geometry: AB2 Species 33. What kind of hybrid orbitals are utilized by the boron atom in BF3 molecules? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: B OBJ: Identify the central atom hybridization given the formula. TOP: Trigonal Planar Electronic Geometry 34. What is the hybridization at the boron atom in gaseous BBr3? a. sp3d b. sp c. sp2 d. sp3 e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the formula. TOP: Trigonal Planar Electronic Geometry
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35. Which of the following molecules has 120 bond angles? a. BeI2 b. CH4 c. H2S d. BCl3 e. NF3 ANS: D OBJ: Identify the formula consistent with the given bond angles. TOP: Trigonal Planar Electronic Geometry 36. Which of the following molecules has 120 bond angles? a. BF4 b. CF4 c. H2O d. BI3 e. NH4+ ANS: D OBJ: Identify the formula consistent with the given bond angles. TOP: Trigonal Planar Electronic Geometry 37. Which one of the following molecules has only 120 bond angles? a. PF3 b. SF6 c. BI3 d. PF5 e. NF3 ANS: C OBJ: Identify the formula consistent with the given bond angles. TOP: Trigonal Planar Electronic Geometry 38. Which one of the following molecules has a central atom that is sp2 hybridized? a. BeF2 b. BCl3 c. PCl3 d. H2O e. NH3 ANS: B OBJ: Identify the formula consistent with the given central atom hybridization. TOP: Trigonal Planar Electronic Geometry 39. Which of the following is a false statement about BF3? a. BF3 has trigonal planar molecular geometry. b. BF3 has trigonal pyramidal electronic geometry. c. All three bond angles in BF3 are 120. d. The B atom does not satisfy the octet rule. e. Although the electronegativity difference between B and F is large (2.0 units), BF3 is a covalent compound. ANS: B OBJ: Apply VSEPR and VB theory given the formula. TOP: Trigonal Planar Electronic Geometry Whitten 10e
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40. Consider the following statements about BCl3 molecules. Which statement is false? a. The BCl bonds are quite polar. b. The bond dipoles exactly cancel. c. The ClBCl bond angles are 109.5. d. BCl3 molecules are nonpolar. e. BCl3 molecules are planar. ANS: C OBJ: Apply VSEPR and VB theory given the formula. TOP: Trigonal Planar Electronic Geometry 41. What kind of hybrid orbitals are utilized by the carbon atom in CF4 molecules? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the formula. TOP: Tetrahedral Electronic Geometry: AB4 Species 42. What is the hybridization at the central atom in SiH4? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the formula. TOP: Tetrahedral Electronic Geometry: AB4 Species 43. Consider a molecule with 109.5 bond angles and sp3 hybridization at the central atom. Which of the following molecules does not fit this description? a. CH3Cl b. SiF4 c. SF4 d. SiCl4 e. CF4 ANS: C OBJ: Identify the formula consistent with the given bond angles and central atom hybridization. TOP: Tetrahedral Electronic Geometry: AB4 Species 44. Consider CH4 and CF4. Electronegativities: C = 2.5, H = 2.1, F = 4.0. Which statement is false? a. Both are sp3 hybridized at carbon. b. The bond angles in CF4 are smaller than those in CH4. c. The CF bonds are more polar than the CH bonds. d. Both molecules are nonpolar. e. The bond dipoles in CF4 are directed toward the fluorine, but those in CH4 are directed toward the carbon atom.
Whitten 10e
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ANS: B OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB4 Species 45. Which statement concerning the ion, SO42, is true? a. The ion's charge results in there being one lone pair of electrons on the S atom. b. There are five regions of high electron density on the S atom. c. The bond angles are 90. d. The electronic geometry is octahedral. e. The hybridization of the S atom is sp3. ANS: E OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB4 Species 46. Which of the following statements about chloroform, CHCl3, is false? a. The hybridization of C is sp3. b. The hybridization of Cl is sp3. c. The bond angles are 109.5. d. The molecule is polar. e. The molecule has tetrahedral electronic geometry. ANS: B OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB4 Species 47. Which response contains all the characteristics listed that should apply to silicon tetrafluoride, SiF4, and no other characteristics? I. tetrahedral II. 120 bond angles III. sp hybridized at C IV. polar molecule V. one unshared pair of electrons on Si a. b. c. d. e.
II and III I I and V II, IV, and V none of these
ANS: B OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB4 Species 48. Which one of the following molecules is polar? a. BCl3 b. CdI2 c. CCl4 d. NCl3 e. BeBr2 ANS: D OBJ: Identify the formula consistent with a polar molecule. TOP: Tetrahedral Electronic Geometry: AB4 Species
Whitten 10e
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49. Which one of the following molecules is polar? a. BeCl2 b. BCl3 c. BF4 d. CH2F2 e. CF4 ANS: D OBJ: Identify the formula consistent with a polar molecule. TOP: Tetrahedral Electronic Geometry: AB4 Species 50. Which one of the following molecules is nonpolar? a. CCl4 b. CH2Cl2 c. CH3Cl d. CHCl3 e. SiH2Cl2 ANS: A OBJ: Identify the formula consistent with a nonpolar molecule. TOP: Tetrahedral Electronic Geometry: AB4 Species 51. Which one of the following molecules is polar? a. BCl3 b. BeI2 c. CCl4 d. CHCl3 e. Br2 ANS: D OBJ: Identify the formula consistent with a polar molecule. TOP: Tetrahedral Electronic Geometry: AB4 Species 52. Molecules such as NF3 are best described by assuming what kind of hybridization at the central atom? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 53. What is the hybridization of the nitrogen atom in NH3? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species
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54. What is the hybridization of the sulfur atom in SO32? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Identify the central atom hybridization given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 55. For AsF3, the electronic geometry is ____ and the molecular geometry is ____. a. tetrahedral; trigonal planar b. trigonal planar; tetrahedral c. tetrahedral; tetrahedral d. trigonal planar; trigonal planar e. trigonal planar; linear ANS: A OBJ: Identify the central atom electron and molecular geometry given a formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 56. The electronic geometry of the central atom in PCl3 is ____. a. pyramidal b. trigonal planar c. tetrahedral d. octahedral e. trigonal bipyramidal ANS: C OBJ: Identify the central atom electron geometry given a formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 57. The molecular geometry of PCl3 is ____. a. pyramidal b. trigonal planar c. tetrahedral d. octahedral e. trigonal bipyramidal ANS: A OBJ: Identify the central atom molecular geometry given a formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 58. Four of the following statements about the ammonia molecule, NH3, are correct. One is not. Which one? a. The ammonia molecule is tetrahedral. b. Since nitrogen is more electronegative than hydrogen, the bond dipoles are directed toward the nitrogen atoms. c. The bond dipoles re-enforce the effect of the unshared pair of electrons on the nitrogen atom. d. The bond angles in the ammonia molecule are less than 109. e. The nitrogen atom can be described as utilizing sp3 hybrid orbitals in the ammonia molecule.
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ANS: A OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 59. Which statement for NH3 and NF3 is false? Electronegativities: N = 3.0, H = 2.1, F = 4.0. a. Both are sp3 hybridized at nitrogen. b. The bond angles in NF3 are smaller than those in NH3. c. The NF3 molecule is more polar than the NH3 molecule. d. Both molecules have one unshared pair of electrons in the outer shell of nitrogen. e. The bond dipoles of NF3 are directed toward fluorine, whereas those in NH3 are directed toward nitrogen. ANS: C OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 60. Four of the following statements about the ammonia molecule, NH3, and the nitrogen trifluoride molecule, NF3, are correct. One is not. Which one? a. The NH3 molecule is more polar than the NF3 molecule. b. The bond dipoles in NF3 are directed toward the more electronegative fluorine atoms. c. The bond dipoles in NF3 oppose the effect of the unshared pair of electrons. d. The nitrogen atom can be described as utilizing sp3 hybrid orbitals in the nitrogen trifluoride molecule. e. Fluorine atoms are larger than hydrogen atoms, and therefore the bond angles in NF3 are greater than in NH3. ANS: E OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 61. Which of the following statements about PBr3 is false? a. It is a polar molecule. b. The PBr bonds are polar c. P is sp3 hybridized. d. The bond angles are slightly larger than 109.5. e. P has one lone pair. ANS: D OBJ: Apply VSEPR and VB theory given the formula. TOP: Tetrahedral Electronic Geometry: AB3U Species 62. Which one of the following is a nonpolar molecule with polar covalent bonds? a. NH3 b. H2Te c. SOCl2 (S is central atom) d. BeBr2 e. HF ANS: D OBJ: Identify the formula consistent with a nonpolar molecule. TOP: Tetrahedral Electronic Geometry: AB3U Species
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63. Which one of the following is a nonpolar molecule with polar bonds? a. H2O b. NH3 c. PF5 d. CHCl3 e. none of these ANS: C OBJ: Identify the formula consistent with a nonpolar molecule. TOP: Tetrahedral Electronic Geometry: AB3U Species 64. The molecular geometry of the hydrogen sulfide molecule is ____. a. linear b. angular c. trigonal planar d. pyramidal e. trigonal bipyramidal ANS: B OBJ: Identify the central atom molecular geometry given the molecule name. TOP: Tetrahedral Electronic Geometry: AB2U2 Species 65. Many simple molecules contain two lone pairs of electrons (unshared pairs) that occupy hybrid orbitals on the central element. Which of the following kinds of electron-electron repulsions are smallest in such molecules? a. bonding pair-bonding pair b. bonding pair-lone pair c. lone pair-lone pair d. depends on hybrid orbitals e. repulsions between all types of pairs of electrons are the same ANS: A OBJ: Identify the weakest electron repulsions. TOP: Tetrahedral Electronic Geometry: AB2U2 Species 66. Many simple molecules contain lone pairs of electrons (also referred to as unshared pairs) which occupy hybrid orbitals of the central element in a molecule. If an atom of the central element utilizes sp3 hybrid orbitals in a compound, which one of the following types of repulsions would be greater? a. bonding pair-bonding pair b. bonding pair-lone pair c. lone pair-bonding pair d. lone pair-lone pair e. repulsions between all types of pairs of electrons are the same ANS: D OBJ: Identify the weakest electron repulsions. TOP: Tetrahedral Electronic Geometry: AB2U2 Species
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67. Which response contains all of the following molecules that can be described as bent or angular molecules and none that have other shapes? BeI2, SO2, H2S, PF3, CO2 a. b. c. d. e.
SO2, H2S BeI2, SO2 BeI2, PF3, CO2 PF3, CO2 another combination
ANS: A OBJ: Apply VSEPR theory given formulas. TOP: Tetrahedral Electronic Geometry: AB2U2 Species 68. Which of the following molecules has the smallest bond angle(s)? a. CH4 b. NH3 c. H2O d. CF4 e. CO2 ANS: C OBJ: Identify the formula consistent with the smallest bond angle. TOP: Tetrahedral Electronic Geometry: AB2U2 Species 69. What is the hybridization of the oxygen atom in H3O+? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: C OBJ: Determine the central atom hybridization given the formula. TOP: Tetrahedral Electronic Geometry: AB2U2 Species 70. Which of the following molecules is sp3 hybridized at the central atom and has bent molecular geometry? a. CH2Cl2 b. NH3 c. SO2 d. OF2 e. CO2 ANS: D OBJ: Identify the formula consistent with the given central atom hybridization and molecular geometry. TOP: Tetrahedral Electronic Geometry: AB2U2 Species
Whitten 10e
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71. Which statement about the water molecule is incorrect? a. The decrease in bond angle from the tetrahedral angle (109.5) is greater for H2O than for NH3. b. The bond angle for H2O is smaller than for NH3 because of the lone pair-lone pair repulsion in H2O. c. The water molecule is very polar. d. The effect of the very polar bonds in water is canceled by the effect of the 2 lone pairs of electrons. e. The O atom is sp3 hybridized. ANS: D OBJ: Apply VSEPR and VB theory given the molecule name. TOP: Tetrahedral Electronic Geometry: AB2U2 Species 72. Consider the chlorine atom in the HCl molecule. Which statement below is true? a. The chlorine atom has tetrahedral electronic geometry. b. The molecule is angular. c. The molecule is nonpolar. d. VSEPR theory and VB theory disagree about the molecular geometry of HCl. e. All of these are true. ANS: A OBJ: Apply VSEPR theory given the formula. TOP: Tetrahedral Electronic Geometry: ABU3 Species 73. An element that is sp3d hybridized and which has no lone pairs of electrons around it in a molecule is at the center of a(n) ____ described by imaginary lines connecting the identical surrounding atoms. a. triangular plane b. tetrahedron c. octahedron d. pyramid e. trigonal bipyramid ANS: E OBJ: Identify the molecular geometry given the central atom hybridization and central atom lone pairs. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 74. What is the hybridization at arsenic in AsF5 molecules? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: D OBJ: Identify the central atom electron geometry given a formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 75. What is the hybridization at the central atom (P) of PF3Cl2? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 Whitten 10e
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ANS: D OBJ: Identify the central atom hybridization given the formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 76. Which one of the following molecules has sp3d hybridization at the central atom? a. PF5 b. NH3 c. SF6 d. HF e. CF4 ANS: A OBJ: Identify the formula consistent with the given central atom hybridization. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 77. How many unshared electrons are there in the highest energy level of phosphorus in the covalent compound PF5? (HINT: Draw Lewis dot formula.) a. eight b. two c. three d. none e. five ANS: D OBJ: Determine the number of central atom lone pairs given a formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 78. Which of the following statements about AsF5 is false? a. The electronic geometry is trigonal bipyramidal. b. As is sp3d hybridized. c. As has one lone pair. d. Bonding angles are 90, 120 or 180. e. The molecular geometry is trigonal bipyramidal. ANS: C OBJ: Apply VSEPR and VB theory given the formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 79. The PF5 molecule exists whereas NF5 does not. Which one of the following is the best explanation for this fact? a. Phosphorus atoms can undergo hybridization involving d orbitals, whereas nitrogen atoms cannot. b. The first five ionization energies of nitrogen are too high but those of phosphorus are not. c. The electron affinity of nitrogen is too high. d. NF5 would be too polar to be stable. e. Simple P5+ ions exist but simple N5+ ions are too small to exist. ANS: A OBJ: Apply a controversial interpretation of VBT in rationalizing experimental data. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3
Whitten 10e
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80. Which of the following statements about SCl4 is false? a. The electronic geometry is trigonal bipyramidal. b. S is sp3d hybridized. c. S has one lone pair. d. Bonding angles are 90, 120 or 180. e. The molecular geometry is trigonal bipyramidal. ANS: E OBJ: Apply VSEPR and VB theory given the formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 81. What is the hybridization of the central I atom in I3? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: D OBJ: Identify the central atom hybridization given the formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 82. Which of the following molecules has three lone pairs of electrons on the central atom? a. XeF4 b. SF4 c. SF6 d. XeF2 e. NCl3 ANS: D TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 83. Which of the following species has trigonal bipyramidal electronic geometry and trigonal bipyramidal molecular geometry? a. SF4 b. BrF3 c. I3 d. XeF2 e. AsCl5 ANS: E OBJ: Identify the formula consistent with the given central atom electron and molecular geometry. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 84. Consider the SeF4 molecule. Where is (are) the lone pair(s) located on the central atom? a. In the axial position. b. In the equatorial position. c. In two octahedral positions at 180 angles from each other. d. In either axial or equatorial positions. e. There are no lone pairs present in SeF4. ANS: B OBJ: Identify the location of any central atom lone pairs given the molecule formula. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3
Whitten 10e
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85. Which one of the following is a polar molecule with nonpolar bonds? a. H2O b. NH3 c. PF5 d. CHCl3 e. none of these ANS: E DIF: Harder Question OBJ: Identify the formula consistent with a nonpolar molecule. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 86. Which response includes all the polar molecules listed and no nonpolar molecules? BCl3, AsF5, NF3, H2S a. b. c. d. e.
BCl3, AsF5 AsF5, NF3, H2S NF3, H2S BCl3, H2S BCl3, NF3
ANS: C OBJ: Identify the formulas of polar molecules. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 87. Which one of the following is a polar molecule with nonpolar bonds? a. H2O b. NH3 c. PF5 d. CHCl3 e. none of these ANS: E DIF: Harder Question OBJ: Identify the formula consistent with a polar molecule. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 88. Which one of the following molecules is polar? a. AsF5 b. PCl3 c. CO2 d. CF4 e. SiH4 ANS: B OBJ: Identify the formula consistent with a polar molecule. TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U2, and AB2U3 89. Which one of the following molecules has an octahedral electron geometry? a. BeCl2 b. SeF6 c. BF3 d. PF5 e. CF4
Whitten 10e
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ANS: B OBJ: Identify the formulas that is not consistent with the given electron geometry. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 90. Which of the following statements about molecules with octahedral electronic geometry is false? a. They are sp3d2 hybridized. b. The molecular geometry is square planar if there are two lone pairs of electrons on the central atom. c. The bond angles are 90, 120 or 180. d. Octahedral geometry is symmetrical. e. If there are two lone pairs of electrons on the central atom they will be 180 apart. ANS: C OBJ: Apply VSEPR and VB theory given the central atom electron geometry. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 91. What is the hybridization at the central element in SeF6? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: E OBJ: Identify the central atom hybridization given the formula. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 92. What is the hybridization at the sulfur atom in SF6? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: E OBJ: Identify the central atom hybridization given the formula. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 93. Draw the dot formula for the noble gas compound xenon tetrafluoride, XeF4. What is the hybridization of xenon? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: E OBJ: Identify the central atom hybridization given the formula. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2
Whitten 10e
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94. Which of the following species has square planar molecular geometry? a. CH4 b. SF4 c. XeF4 d. NH4+ e. SO42 ANS: C OBJ: Identify the formula consistent with given molecular geometry. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 95. Which of the following species has square pyramidal molecular geometry? a. PF5 b. NH4+ c. SbCl5 d. IF5 e. SiCl4 ANS: D OBJ: Identify the formula consistent with given molecular geometry. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 96. Which of the following species does not have octahedral electronic geometry? a. IF4 b. BrCl5 c. XeF4 d. PF6 e. AsF5 ANS: E OBJ: Identify the formulas that is not consistent with the given electron geometry. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 97. The central atom of which of the following species does not have sp3d2 hybridization? a. XeF4 b. SeF6 c. PF6 d. IF7 e. ClF5 ANS: D OBJ: Identify the formula not consistent with the given central atom hybridization. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2 98. Which one of the following molecules is polar? a. SiH4 b. SF6 c. H2 d. PCl5 e. SF4 ANS: E OBJ: Identify the formula consistent with a polar molecule. TOP: Octahedral Electronic Geometry: AB6, AB5U, and AB4U2
Whitten 10e
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99. Which of the following statements about multiple bonds is true? a. A double bond consists of two sigma bonds. b. A sigma bond results from the side-on overlap of p atomic orbitals. c. A pi bond results from the head-on overlap of p atomic orbitals. d. sp2 hybridization in carbon is associated with one double bond and two single bonds. e. sp3 hybridization in carbon is associated with one double bond and two single bonds. ANS: D OBJ: Understand the VBT interpretation of multiple bonds. TOP: Compounds Containing Double or Triple Bonds 100. How many sigma ()bonds and how many pi () bonds does the ethene molecule contain?
a. b. c. d. e.
4 , 2 5 , 2 5 , 1 5 , 0 8 , 2
ANS: C OBJ: Determine the number of sigma and pi bonds given the Lewis structure. TOP: Compounds Containing Double or Triple Bonds 101. What is the hybridization of a carbon atom involved in a double bond? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: B OBJ: Identify the hybridization of an atom in a molecule given its bonding. TOP: Compounds Containing Double or Triple Bonds 102. What is the geometry of a carbon atom involved in one double bond? a. linear b. trigonal planar c. tetrahedral d. trigonal bipyramidal e. octahedral ANS: B OBJ: Identify the geometry of an atom in a molecule given its bonding. TOP: Compounds Containing Double or Triple Bonds
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103. Choose the following false statement. a. A sigma bond is a bond resulting from head-on overlap of atomic orbitals. b. A pi bond is a bond resulting from side-on overlap of atomic orbitals. c. A double bond consists of one sigma bond and one pi bond. d. A triple bond may consist of one sigma bond and two pi bonds or of two sigma bonds and one pi bond. e. A carbon atom involved in a double bond may not be sp3 hybridized. ANS: D OBJ: Understand the VBT interpretation of covalent bonding. TOP: Compounds Containing Triple Bonds 104. Which of the following statements regarding a carbon atom involved in 2 double bonds is false? a. The geometry is linear. b. The hybridization is sp. c. There are 2 sigma and two pi bonds. d. The C atom has two unhybridized p atomic orbitals. e. The C atom can make one more bond to complete its octet. ANS: E OBJ: Apply the VBT interpretation of covalent bonding. TOP: Compounds Containing Triple Bonds 105. How many sigma () bonds and how many pi () bonds does the acetylene molecule contain? a. 5 and 1 b. 2 and 3 c. 3 and 1 d. 2 and 2 e. 3 and 2 ANS: E OBJ: Determine the number of sigma and pi bonds given the molecule name. TOP: Compounds Containing Triple Bonds 106. What is the hybridization of a carbon atom involved in a triple bond? a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: A OBJ: Identify the central atom hybridization given the bonding of an atom in a molecule. TOP: Compounds Containing Triple Bonds 107. What is the geometry of a carbon atom involved in a triple bond? a. linear b. trigonal planar c. tetrahedral d. trigonal bipyramidal e. octahedral ANS: A OBJ: Identify the central atom geometry given the bonding of an atom in a molecule. TOP: Compounds Containing Triple Bonds Whitten 10e
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108. Which of the following responses contains all of the true statements for ethyne? I. The ethyne molecule has a double bond between its 2 carbon atoms. II. The ethyne molecule has a triple bond between its 2 carbon atoms. III. One pi bond is formed between the 2 carbon atoms by head-on overlap of the sp hybrid orbitals. IV. One sigma bond is formed between the 2 carbon atoms by head-on overlap of the sp2 hybrid orbitals. V. The ethyne molecule is linear. a. b. c. d. e.
I and III II and IV I and IV II and V II and III
ANS: D OBJ: Apply VSEPR and VB theory given the molecule name. TOP: Compounds Containing Triple Bonds 109. Choose the species that is incorrectly matched with the electronic geometry about the central atom.
a. b. c. d. e.
Molecule / Electronic Geometry CF4 / tetrahedral BeBr2 / linear H2O / tetrahedral NH3 / tetrahedral PF3 / pyramidal
ANS: E OBJ: Determine if a formula is consistent with the given electron geometry. TOP: A Summary of Electronic and Molecular Geometries 110. Choose the species that is incorrectly matched with the electronic geometry about the central atom.
a. b. c. d. e.
Molecule / Electronic Geometry SiH4 / tetrahedral SO2 / trigonal planar NH2- / tetrahedral NH3 / tetrahedral BH4 / trigonal planar
ANS: E OBJ: Determine if a formula is consistent with the given electron geometry. TOP: A Summary of Electronic and Molecular Geometries 111. Choose the species that is incorrectly matched with the electronic geometry about the central atom.
a. b. c. d. e.
Molecule / Electronic Geometry PCl5 / trigonal bipyramidal SF6 / octahedral XeF2 / trigonal bipyramidal XeF4 / octahedral GeCl4 / trigonal bipyramidal
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ANS: E OBJ: Determine if a formula is consistent with the given electron geometry. TOP: A Summary of Electronic and Molecular Geometries 112. Choose the species that is incorrectly matched with the electronic geometry about the central atom.
a. b. c. d. e.
Ion / Electronic Geometry NO2 / trigonal planar ClO4 / tetrahedral SO32 / pyramidal ClO3 / tetrahedral BrO4 / tetrahedral
ANS: C OBJ: Determine if a formula is consistent with the given electron geometry. TOP: A Summary of Electronic and Molecular Geometries 113. Which molecule is incorrectly matched with the molecular geometry?
a. b. c. d. e.
Molecule / Molecular Geometry CCl4 / tetrahedral PH3 / pyramidal BeCl2 / linear BBr3 / trigonal planar SO2 / linear
ANS: E OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 114. Which molecule is incorrectly matched with the molecular geometry?
a. b. c. d. e.
Molecule / Molecular Geometry I3 / linear BrF3 / T-shaped BH4 / tetrahedral SbCl5 / trigonal bipyramidal NO2 / tetrahedral
ANS: E OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 115. Which molecule is incorrectly matched with the molecular geometry?
a. b. c. d. e.
Molecule / Molecular Geometry SeF6 / octahedral CCl4 / tetrahedral SO3 / pyramidal SF4 / tetrahedral SbH3 / pyramidal
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ANS: D OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 116. Which molecule is incorrectly matched with the molecular geometry?
a. b. c. d. e.
Molecule / Molecular Geometry SF6 / octahedral AsH3 / pyramidal BCl3 / trigonal planar AsF5 / trigonal bipyramidal H2S / linear
ANS: E OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 117. Which molecule is incorrectly matched with the molecular geometry?
a. b. c. d. e.
Molecule / Molecular Geometry SO32 / pyramidal SO3 / trigonal planar SO42 / tetrahedral ClO3 / tetrahedral ClO / linear
ANS: D OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 118. Which one of the following pairs of molecules and molecular geometries is incorrectly matched?
a. b. c. d. e.
Compound / Molecular Geometry NF3 / pyramidal H2O / angular BF3 / trigonal planar AsF5 / pentagonal planar SeF6 / octahedral
ANS: D OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 119. Which one of the following pairs of molecules and molecular geometries is incorrectly matched?
a. b. c. d. e.
Compound / Molecular Geometry HBr / linear CBr4 / tetrahedral AsH3 / pyramidal BeBr2 / angular CH4 / tetrahedral
ANS: D OBJ: Determine if a formula is consistent with the given molecular geometry. TOP: A Summary of Electronic and Molecular Geometries Whitten 10e
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120. Which response includes all of the molecules listed that have the same molecular geometry as electronic geometry, and only those molecules? BCl3, AsF5, NF3, H2S a. b. c. d. e.
BCl3, AsF5 AsF5, NF3, H2S NF3, H2S BCl3, H2S BCl3, NF3
ANS: A OBJ: Identify the molecules with identical electron and molecular geometries, given the formulas. TOP: A Summary of Electronic and Molecular Geometries 121. Which one of the following molecules has a central atom that is not sp3 hybridized? a. H2O b. NH3 c. CH4 d. CHCl3 e. SF4 ANS: E OBJ: Identify the formula not consistent with the given central atom hybridization. TOP: A Summary of Electronic and Molecular Geometries 122. Which of the following molecules does not have tetrahedral electronic geometry? a. SF4 b. SO32 c. ClO3 d. ClO2 e. CCl2F2 ANS: A OBJ: Identify the formula not consistent with given electron geometry. TOP: A Summary of Electronic and Molecular Geometries 123. Which, if any, of the compounds listed are not sp3 hybridized at the central atom? I. CF4 II. H2O III. SiF4 IV. CHCl3 V. NH3 a. b. c. d. e.
III and IV I, II, and III II, IV, and V III and V all are sp3 hybridized
ANS: E OBJ: Identify the formulas not consistent with the given central atom hybridization. TOP: A Summary of Electronic and Molecular Geometries
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124. Which, if any, of the compounds listed are not sp3d hybridized at the central atom? I. BF3 II. AsI5 III. SF4 IV. BrF5 V. XeF4 a. b. c. d. e.
III and IV I, II, and III I, IV, and V III and V all are sp3d hybridized
ANS: C OBJ: Identify the formulas not consistent with the given central atom hybridization. TOP: A Summary of Electronic and Molecular Geometries 125. Which species is incorrectly matched with the hybridization at the central atom?
a. b. c. d. e.
Species / Hybridization at Central Atom SeF6 / sp3d CO2 / sp NH4+ / sp3 BCl3 / sp2 BeBr2 / sp
ANS: A OBJ: Identify the formulas not consistent with the given central atom hybridization. TOP: A Summary of Electronic and Molecular Geometries 126. Which species is incorrectly matched with the hybridization at the central atom?
a. b. c. d. e.
Species / Hybridization at Central Atom SO2 / sp2 CF4 / sp3 PF5 / sp3d2 SeO42 / sp3 HCN / sp
ANS: C OBJ: Identify the formulas not consistent with the given central atom hybridization. TOP: A Summary of Electronic and Molecular Geometries 127. Which species is incorrectly matched with bond angles?
a. b. c. d. e.
Molecule / Bond Angles SiCl4 / 109.5 BeI2 / slightly less than 109 SF6 / 90 (and 180) AsF5 / 90, 120 (and 180) BF3 / 120
ANS: B OBJ: Identify the formulas not consistent with the given bond angles. TOP: A Summary of Electronic and Molecular Geometries Whitten 10e
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128. Which species is incorrectly matched with bond angles?
a. b. c. d. e.
Molecule / Bond Angles CI4 / 109.5 BeF2 / 180 HI / 90 I3 / 180 BI3 / 120
ANS: C OBJ: Identify the formulas not consistent with the given bond angles. TOP: A Summary of Electronic and Molecular Geometries 129. Which species is incorrectly matched with bond angles?
a. b. c. d. e.
Molecule / Bond Angles HCl / 180 ClO3 / slightly less than 109 NH3 / 107 SeO4 / 109.5 SnCl4 / 90, 120 (and 180)
ANS: E OBJ: Identify the formulas not consistent with the given bond angles. TOP: A Summary of Electronic and Molecular Geometries 130. Which species is incorrectly matched with bond angles?
a. b. c. d. e.
Molecule / Bond Angles NCl3 / 120 BeBr2 / 180 CCl4 / 109.5 PCl5 / 120 and 90 (and 180) SeF6 / 90 (and 180)
ANS: A OBJ: Identify the formulas not consistent with the given bond angles. TOP: A Summary of Electronic and Molecular Geometries 131. What is the molecular geometry around an atom in a molecule or ion which is surrounded by
two lone pairs of electrons and two single bonds. a. b. c. d. e.
bent trigonal pyramidal tetrahedral linear trigonal planar
ANS: A DIF: easy OBJ: Identify the central atom molecular geometry given the number of lone pairs and bonds. TOP: A Summary of Electronic and Molecular Geometries
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132. What is the electron geometry (or electron arrangement) around an atom in a molecule or ion
which is surrounded by one lone pair of electrons and four single bonds. a. b. c. d. e.
trigonal bipyramidal see-saw or distorted tetrahedron T-shaped linear trigonal planar
ANS: A DIF: easy OBJ: Determine the electron geometry given the number of lone pairs and bonding pairs around the central atom. TOP: A Summary of Electronic and Molecular Geometries 133. What is the bond angle in a trigonal planar molecule or ion? a. 109° b. 180° c. 90° d. 72° e. 120° ANS: E DIF: easy OBJ: Identify the bond angle of a particular molecular geometry. TOP: A Summary of Electronic and Molecular Geometries 134. What is the molecular geometry around the nitrogen atom?
a. b. c. d. e.
trigonal pyramidal bent tetrahedral see-saw or distorted tetrahedral trigonal planar
ANS: A DIF: moderate OBJ: Determine the molecular geometry around an atom given the Lewis structure. TOP: A Summary of Electronic and Molecular Geometries
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135. When an atom in a molecule or ion is described as sp hybridized, its molecular geometry is a. b. c. d. e.
linear. octahedral. trigonal bipyramidal. tetrahedral. trigonal planar.
ANS: A DIF: easy OBJ: Determine the molecular geometry given the central atom hybridization. TOP: Valence Bond (VB) Theory 136. Which of the labeled carbons (C1-C4) is sp-hybridized?
a. carbon three b. carbon one c. carbon two and four d. carbon two e. carbon one and three ANS: A DIF: easy OBJ: Identify the atom in the Lewis structure with the specified hybridization. TOP: Valence Bond (VB) Theory 137. Which of the following molecules is nonpolar? a. b. c. d. e.
phosphorus trifluoride, PF3 sulfur tetrafluoride, SF4 hydrogen fluoride, HF boron trifluoride, BF3 sulfur dioxide, SO2
ANS: D DIF: moderate OBJ: Identify the nonpolar molecule. TOP: Polar and Nonpolar Molecules
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138. How many sigma and pi bonds are in the molecule pictured below?
a. b. c. d. e.
thirteen sigma bonds and one pi bond eleven sigma bonds and two pie bonds thirteen sigma bonds and two pie bonds eleven sigma bonds and five pie bonds five sigma bonds and eleven pie bonds
ANS: A DIF: easy OBJ: Determine the number of sigma and pi bonds in the molecule given the Lewis structure. TOP: Compounds Containing Double or Triple Bonds 139. What is the electron geometry around the nitrogen atom?
a. b. c. d. e.
tetrahedral trigonal planar trigonal pyramidal T-shaped trigonal bipyramidal
ANS: A DIF: moderate OBJ: Determine the electron geometry of the specified atom given the Lewis structure. TOP: A Summary of Electronic and Molecular Geometries 140. What is the electron geometry around carbon atom C2?
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a. b. c. d. e.
trigonal planar linear tetrahedral trigonal pyramidal bent
ANS: B DIF: moderate OBJ: Determine the molecular or electron geometry around the specified atom given the Lewis structure. TOP: A Summary of Electronic and Molecular Geometries 141. What is the shape (molecular geometry) of PCl3? a. trigonal planar b. bent c. trigonal pyramidal d. tetrahedral e. trigonal bipyramidal ANS: C OBJ: Apply VSEPR theory given the formula. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 142. What is the shape (molecular geometry) of XeO3? a. trigonal planar b. trigonal pyramidal c. trigonal bipyramidal d. seesaw e. bent ANS: B OBJ: Apply VSEPR theory given the formula. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 143. What is the shape (molecular geometry) of IBr3? a. trigonal planar b. trigonal pyramidal c. trigonal bipyramidal d. T-shaped e. seesaw ANS: D OBJ: Apply VSEPR theory given the formula. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory
Use the following Lewis structure for acetic acid to answer the following questions:
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144. The ideal value for the H-C-H bond angle about atom 1 is: a. 60o b. 90o c. 109.5o d. 120o
e. 180o
ANS: C OBJ: Identify the ideal bond angle. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 145. The geometry about atom 3 is: a. linear b. bent c. trigonal planar d. tetrahedral e. trigonal pyramidal ANS: B OBJ: Identify the geometry around a certain atom in a structural formula. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory
Use the following Lewis structure for acetamide to answer the following questions:
146. The ideal value for the C-C-N bond angle around atom 2 is: a. 60o b. 90o c. 109.5o d. 120o
e. 180o
ANS: D OBJ: Identify the ideal bond angle. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 147. The ideal value for the C-N-H bond angle around atom 3 is: a. 60o b. 90o c. 109.5o d. 120o
e. 180o
ANS: C OBJ: Identify the ideal bond angle. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 148. Draw the Lewis structure for SiH4 to decide whether it is polar or nonpolar. a. polar b. nonpolar ANS: B NAT: Draw the Lewis structure given the formula and infer the molecule polarity from the Lewis structure. TOP: Polar and Nonpolar Molecules 149. Draw the Lewis structure for SbF3 to decide whether it is polar or nonpolar. a. polar b. nonpolar ANS: A OBJ: Draw the Lewis structure given the formula and infer the molecule polarity from the Lewis structure. TOP: Polar and Nonpolar Molecules
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150. What does the following figure represent?
a. b. c. d. e.
the overlap of two 2p orbitals to form a pi bond the overlap of two 2p orbitals to form a sigma bond the overlap of two 1s orbitals to form a pi bond the overlap of a 1s orbital and a 2p orbital to form a sigma bond the overlap of a 1s orbital and a 2p orbital to form a pi bond
ANS: B OBJ: Identify the correct description of sigma orbital overlap. TOP: Valence Bond (VB) Theory 151. What does the following figure represent?
a. b. c. d. e.
the overlap of two 2p orbitals to form a pi bond the overlap of two 2p orbitals to form a sigma bond the overlap of two 1s orbitals to form a pi bond the overlap of a 1s orbital and a 2p orbital to form a sigma bond the overlap of a 1s orbital and a 2p orbital to form a pi bond
ANS: D OBJ: Identify the correct description of sigma orbital overlap. TOP: Valence Bond (VB) Theory 152. What does the following figure represent?
a. b. c. d. e.
the overlap of two 1s orbitals to form a pi bond the overlap of two 1s orbitals to form a sigma bond the overlap of two 2p orbitals to form a sigma bond the overlap of a 1s orbital and a 2s orbital to form a sigma bond the overlap of a 1s orbital and a 2s orbital to form a pi bond
ANS: A OBJ: Identify the correct description of sigma orbital overlap. TOP: Valence Bond (VB) Theory
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153. What type of hybridization is represented in the figure below?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
ANS: E OBJ: Identify the hybrid orbital. TOP: Valence Bond (VB) Theory 154. What type of hybridization is represented in the figure below?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
ANS: C OBJ: Identify the hybrid orbital. TOP: Valence Bond (VB) Theory 155. What type of hybridization is represented in the figure below?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
ANS: B OBJ: Identify the hybrid orbital. TOP: Valence Bond (VB) Theory 156. What type of hybridization is represented in the figure below?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
ANS: D OBJ: Identify the hybrid orbital. TOP: Valence Bond (VB) Theory
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157. A molecule has sp3d2 hybridization with 1 lone pair. What is the geometry of this molecule? a. trigonal bipyramidal b. see saw c. T-shaped d. octahedral e. square pyramidal ANS: E OBJ: Determine the molecular geometry given the hybridization and number of lone pairs. TOP: Valence Bond (VB) Theory 158. A molecule has sp3 hybridization with 1 lone pair. What is the geometry of this molecule? a. tetrahedral b. trigonal planar c. trigonal pyramidal d. bent e. trigonal bipyramidal ANS: C OBJ: Determine the molecular geometry given the hybridization and number of lone pairs. TOP: Valence Bond (VB) Theory 159. How many and bonds does C have in HCN? a. 1 and 1 b. 1 and 2 c. 2 and 1
d. 2 and 2
e. 3 and 1
ANS: D OBJ: Determine the number of sigma and pi bonds given the formula. TOP: Valence Bond (VB) Theory 160. If an atom has sp hybridization in a molecule, what is the maximum number of and 2
bonds that the atom can form? a. 3 and 1 b. 2 and 2 c. 2 and 1 d. 3 and 0 e. 1 and 2 ANS: A OBJ: Determine the maximum number of sigma and pi bonds possible given the hybridization. TOP: Valence Bond (VB) Theory 161. If an atom has sp hybridization in a molecule, what is the maximum number of and bonds
that the atom can form? a. 1 and 1 b. 1 and 2 c. 2 and 1 d. 2 and 2 e. 3 and 1 ANS: D OBJ: Determine the maximum number of sigma and pi bonds possible given the hybridization. TOP: Valence Bond (VB) Theory
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SHORT ANSWER
Use the figures below to answer the following questions:
A
B
C
D
E
1. Which of the figures represents sp hybridization? ANS: A OBJ: Identify the correct hybridized orbital. TOP: Valence Bond (VB) Theory 2. Which of the figures represents sp2 hybridization? ANS: B OBJ: Identify the correct hybridized orbital. TOP: Valence Bond (VB) Theory 3
3. Which of the figures represents sp hybridization? ANS: C OBJ: Identify the correct hybridized orbital. TOP: Valence Bond (VB) Theory 3
4. Which of the figures represents sp d hybridization? ANS: D OBJ: Identify the correct hybridized orbital. TOP: Valence Bond (VB) Theory 3 2
5. Which of the figures represents sp d hybridization? ANS: E OBJ: Identify the correct hybridized orbital. TOP: Valence Bond (VB) Theory CONCEPTUAL 1. The actual bond angle in the water molecule is about 104. Discuss the likelihood the electronic geometry of the water molecule is square planar instead of tetrahedral. OBJ: Explain the factors responsible for the tetrahedral molecular geometry. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory | Valence Bond (VB) Theory
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2. Explain why sulfur can share 10 or 12 electrons, yet oxygen, in the same group, cannot. OBJ: Explain the origin of the exceptions to the octet rule. TOP: Valence Bond (VB) Theory | Lewis Structures 3. Discuss how the Valence Bond theory explains why Be can make 2 and only 2 bonds. OBJ: Explain how VBT limits the number of bonds in a molecule. TOP: Valence Bond (VB) Theory 4. In terms of the geometry of the orbitals, explain why a quadruple bond is not possible. OBJ: Describe the orbital atomic geometry required to form a quadruple bond. TOP: Compounds Containing Double or Triple Bonds | Compounds Containing Triple Bonds | Valence Bond (VB) Theory 5. Double bonds count as only one region of high electron density instead of two. Comment on how the fact that CO2 is nonpolar confirms this. OBJ: Explain why multiple bonds are treated as a single electron group in VSEPR TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory 6. Consider a theoretical XeF6 molecule. What would you predict for hybridization of the orbitals? Can you think of a possible geometry? OBJ: Describe the central atom electronic and molecular geometry, and hybridization of theoretical molecule. TOP: Valence Shell Electron Pair Repulsion (VSEPR) Theory | Valence Bond (VB) Theory
Chapter 9—Molecular Orbitals in Chemical Bonding MULTIPLE CHOICE 1. When two atomic orbitals overlap in phase, all of the following occur except: a. constructive interference occurs b. a bonding molecular orbital is produced c. the energy of the orbital is always higher and therefore more stable d. the orbitals are added, not subtracted e. all of these occur, without exception ANS: C OBJ: Define in-phase atomic orbital overlap. TOP: Molecular Orbitals 2. Which of the following statements about Molecular Orbital theory is false? a. Pi molecular orbitals are always antibonding orbitals. b. Molecular orbitals are shared equally by all atoms in the molecule. c. s atomic orbitals always produce sigma molecular orbitals. d. Sigma molecular orbitals are either bonding or antibonding orbitals. e. Molecular orbitals are formed by either head-on or side-on overlap of atomic orbitals. ANS: A OBJ: Define MO theory. Whitten 10e
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TOP: Molecular Orbitals 3. Which statement is false? A sigma molecular orbital a. may result from side-on overlap of p atomic orbitals. b. may result from head-on overlap of p atomic orbitals. c. may result from overlap of an s atomic orbital with a p atomic orbital. d. appears spherical when viewed along its major axis (axis of overlap). e. may be either bonding or antibonding. ANS: A OBJ: Define a sigma molecular orbital. TOP: Molecular Orbitals 4. Which statement about bonding molecular orbitals is incorrect? a. Electrons in bonding orbitals tend to stabilize the molecule. b. Only bonds can result from bonding molecular orbitals. c. In a bonding molecular orbital, the electron density is high between the two atoms. d. Bonding molecular orbitals result from addition of the wave functions of the atomic orbitals. e. The relative numbers of electrons in bonding versus antibonding orbitals determines the overall stability of the molecule. ANS: B OBJ: Describe bonding molecular orbitals. TOP: Molecular Orbitals
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5. Which statement is true? A pi molecular orbital a. may result from side-on overlap of p atomic orbitals. b. may result from head-on overlap of p atomic orbitals. c. may result from overlap of an s atomic orbital with a p atomic orbital. d. appears spherical when viewed along its major axis (internuclear axis). e. can only be an antibonding orbital. ANS: A OBJ: Define a pi molecular orbital. TOP: Molecular Orbitals 6. Which statement is false? a. The energy of a bonding orbital is always lower than the energies of the combining atomic orbitals. b. The energy of an antibonding orbital is always higher than the energies of the combining atomic orbitals. c. The number of molecular orbitals formed is equal to twice the number of atomic orbitals that have combined. d. An antibonding orbital is always less stable than the original combining atomic orbitals. e. A bonding molecular orbital has a high electron density between the two nuclei while an antibonding molecular orbital has a node between the nuclei. ANS: C OBJ: Describe molecular orbitals. TOP: Molecular Orbitals 7. The overlap of the 2p atomic orbitals produces ____ sigma molecular orbitals and ____ pi molecular orbitals. a. 2; 3 b. 2; 4 c. 4; 2 d. 1; 2 e. 3; 3 ANS: B OBJ: Determine the number of molecular orbitals. TOP: Molecular Orbitals 8. How many MOs are formed by the combination of the p atomic orbitals of 2 atoms? a. 1 b. 2 c. 4 d. 6 e. 12 ANS: D OBJ: Determine the number of molecular orbitals. TOP: Molecular Orbitals
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9. The out-of-phase head-on overlap of a pair of 2p orbitals forms a ____ molecular orbital. a. 2p b. *2p c. 2p d. *2p e. 2s ANS: B OBJ: Identify the molecular orbital. TOP: Molecular Orbitals 10. The in-phase side-on overlap of a pair of 2p orbitals forms a ____ molecular orbital. a. 2p b. *2p c. 2p d. *2p e. 2s ANS: C OBJ: Identify the molecular orbital. TOP: Molecular Orbitals 11. The in-phase overlap of the 2p orbitals forms ____ sigma molecular orbitals and ____ pi molecular orbitals. a. 2; 2 b. 2; 4 c. 1; 2 d. 2; 2 e. 4; 2 ANS: C OBJ: Determine the number of molecular orbitals. TOP: Molecular Orbitals 12. The molecular orbital energy level diagram has the 2p orbital at a lower energy level that the two 2p orbitals for which of the following molecules? a. C2 b. N2 c. B2 d. O2 e. Li2 ANS: D OBJ: Match the MO diagram detail with the molecule. TOP: Molecular Orbital Energy Level Diagrams 13. The molecular orbital energy level diagram has the 2p orbital at a higher energy level than the two 2p orbitals for which of the following species? a. O2 b. O2 c. N2 d. F2 e. O2+ ANS: C Whitten 10e
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OBJ: Match the MO diagram detail with the molecule. TOP: Molecular Orbital Energy Level Diagrams 14. Which statement is false? a. Electrons occupy MOs by following the Aufbau Principle. b. Electrons occupy MOs by following the Pauli Exclusion Principle. c. Electrons occupy MOs by following Hund's Rule. d. In MO theory all electrons are accounted for, not just the valence electrons. e. No two molecular orbitals for any molecule ever have the same energy. ANS: E OBJ: Define an MO diagram. TOP: Molecular Orbital Energy Level Diagrams 15. Which of the following statements about molecular orbitals is false? a. Degenerate molecular orbitals follow Hund's Rule. b. There is a slightly different molecular orbital diagram for Z < 8 and Z 8. c. s molecular orbitals are lower in energy than s*, at a given energy level. d. Antibonding molecular orbitals are never occupied with electrons. e. Molecular orbitals are occupied using the Aufbau Principle. ANS: D OBJ: Define an MO diagram. TOP: Molecular Orbital Energy Level Diagrams 16. Which of the following statements concerning the molecular orbital energy level diagrams for first and second period homonuclear diatomic molecules is false? a. The two 2p orbitals have the same energy. b. The two *2p orbitals have the same energy. c. The diagram for H2, He2, Li2, Be2, B2, C2, and N2 molecules has the two 2p orbitals at a lower energy than the 2p orbital. d. The diagram for O2, F2, and Ne2 molecules has the *2p orbital at a lower energy than the two *2p orbitals. e. The bonding orbitals always have lower energy than the antibonding orbitals formed from the same set of atomic orbitals. ANS: D OBJ: Define an MO diagram. TOP: Molecular Orbital Energy Level Diagrams 17. What is the best definition of bond order? a. A bond resulting from the occupation of a pi molecular orbital. b. The amount of energy required to break one mole of bonds. c. A bond resulting from the occupation of a sigma molecular orbital. d. The number of bonding molecular orbitals minus the number of antibonding molecular orbitals. e. Half the number of electrons in bonding molecular orbitals minus half the number of electrons in antibonding molecular orbitals. ANS: E OBJ: Define bond order. TOP: Bond Order and Bond Stability
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18. What is the bond order for a molecule with 10 electrons in bonding molecular orbitals and 5 electrons in antibonding molecular orbitals? a. 1 b. 2 c. 2.5 d. 3 e. 5 ANS: C OBJ: Determine the bond order given the number of bonding and antibonding electrons. TOP: Bond Order and Bond Stability 19. What is the bond order of a species with 10 bonding electrons and 6 antibonding electrons? a. 1 b. 1.5 c. 2 d. 2.5 e. 3 ANS: C OBJ: Determine the bond order given the number of bonding and antibonding electrons. TOP: Bond Order and Bond Stability 20. Which statement is false? a. Bond energy is a measure of bond strength. b. A diatomic molecule with a fractional bond order must be paramagnetic. c. A diatomic molecule with an integral bond order must be diamagnetic. d. A molecule with a bond order greater than zero would be more stable than the separate atoms. e. The larger the bond order of a diatomic species, the more stable it is expected to be. ANS: C OBJ: Define bond order. | Define bond energy. TOP: Bond Order and Bond Stability 21. Which statement concerning bond order is false? a. The bond order usually corresponds to the number of bonds described by the valence bond theory. b. A diatomic molecule with a fractional bond order contains an odd number of electrons. c. A bond order equal to zero means that a molecule is no more stable than the separate atoms. d. The greater the bond order for a bond between 2 atoms, the longer the length of the bond between them. e. The greater the bond order for a bond between 2 atoms, the greater the bond energy for that bond. ANS: D OBJ: Describe bond order. TOP: Bond Order and Bond Stability
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22. The molecular orbital electron configuration given below is for what neutral homonuclear diatomic molecule? s2 *s2 s2 *s2 2py2 2pz2 a. b. c. d. e.
N2 N22+ C2 BN B22
ANS: C DIF: Harder Question OBJ: Identify the formula consistent with the MO electron configuration. TOP: Homonuclear Diatomic Molecules 23. Which of the molecular orbital electron configurations given below is correct for O2? a. 1s2 *1s2 2s2 *2s2 2p2 2py2 2pz2 *2p2 *2p1 b. 1s2 *1s2 2s2 *2s2 2py2 2pz2 2p2 *2py2 *2pz1 c. 1s2 *1s2 2s2 *2s2 2p2 2py2 2pz2 *2py2 *2pz1 d. 1s2 *1s2 2s2 *2s2 2py2 2pz2 2p2 *2p2 *2p1 2 * 2 2 * 2 2 2 * 2 * 2 e. 1s 1s 2s 2s 2py 2pz 2py 2pz *2p1 ANS: C OBJ: Identify the MO electron diagram consistent with the formula. TOP: Homonuclear Diatomic Molecules 24. Draw the molecular orbital diagram for B2. The number of electrons in the 2pz molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: A OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 25. Draw the molecular orbital diagram for C2. The number of electrons in the 2pz molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: B OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules
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26. Draw the molecular orbital diagram for C2. The number of electrons in the 2p molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: E OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 27. Draw the molecular orbital diagram for N2. The number of electrons in antibonding molecular orbitals is ____. a. 6 b. 2 c. 10 d. 4 e. zero ANS: D OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 28. Draw the molecular orbital diagram for N2. The number of electrons in the 2p molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: B OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 29. Draw the molecular orbital diagram for O2. The number of electrons in the *2pz molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: A OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 30. Draw the molecular orbital diagram for O2. The number of electrons in bonding molecular orbitals is ____. a. 10 b. 6 c. 8 d. 4 e. zero Whitten 10e
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ANS: A OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 31. Draw the molecular orbital diagram for O2. The number of electrons in the *2p molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: E OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 32. Draw the molecular orbital diagram for O2. The number of unpaired electrons is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: B OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 33. Draw the molecular orbital diagram for F2. The number of electrons in the *2p molecular orbital is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: E OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 34. The total numbers of electrons in the 2p molecular orbitals of B2 is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: B OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules
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35. The total numbers of electrons in the *2p molecular orbitals of F2 is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: D OBJ: Determine the MO diagram given the molecule formula. TOP: Homonuclear Diatomic Molecules 36. What is the bond order for B2? a. 1 b. 2 c. 3 d. 1.5 e. 2.5 ANS: A OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 37. What is the bond order for C2? a. 1 b. 2 c. 3 d. 1.5 e. zero ANS: B OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 38. What is the bond order for N2? a. 1 b. 2 c. 3 d. 1.5 e. 2.5 ANS: C OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 39. What is the bond order in O2? a. 1 b. 2 c. 3 d. 2.5 e. 1.5 ANS: B OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules
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40. What is the bond order for Ne2? a. 1 b. 2 c. 3 d. zero e. 2.5 ANS: D OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 41. The number of unpaired electrons in the O2 molecule is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: B OBJ: Determine number of unpaired electrons given the molecule formula. TOP: Homonuclear Diatomic Molecules 42. The number of unpaired electrons in the C2 molecule is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: E OBJ: Determine number of unpaired electrons given the molecule formula. TOP: Homonuclear Diatomic Molecules 43. The number of unpaired electrons in the B2+ ion is ____. a. 1 b. 2 c. 3 d. 4 e. zero ANS: A OBJ: Determine number of unpaired electrons given the molecule formula. TOP: Homonuclear Diatomic Molecules 44. Which response lists only the molecules given below that have unpaired electrons? Li2, Be2, B2, C2, N2 a. b. c. d. e.
B2 Be2 N2 Li2 and B2 Be2 and N2
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ANS: A OBJ: Determine the paramagnetic molecules given the molecule formulas. TOP: Homonuclear Diatomic Molecules 45. Which response lists only the molecules given below that are paramagnetic? B2, C2, N2, O2, F2 a. b. c. d. e.
B2 and N2 B2 and O2 N2 and O2 N2 and F2 C2, O2, and F2
ANS: B OBJ: Determine the paramagnetic molecules given the molecule formulas. TOP: Homonuclear Diatomic Molecules 46. Which response lists only the molecules given below that are diamagnetic? Li2, Be2, N2, O2, He2 a. b. c. d. e.
O2 and N2 Li2, Be2, N2, and He2 Li2, Be2, and He2 N2 and He2 He2
ANS: B OBJ: Determine the diamagnetic molecules given the molecule formulas. TOP: Homonuclear Diatomic Molecules 47. Which of the molecular orbital electron configurations given below is correct for C22+? a. 1s2 *1s2 2s2 *2s2 2p2 b. 1s2 *1s2 2s2 *2s2 2py2 c. 1s2 *1s2 2s2 *2s2 d. 1s2 *1s2 2s2 *2s2 2py2 2pz1 e. 1s2 *1s2 2s2 *2s2 2py1 2pz1 ANS: E OBJ: Identify the MO electron diagram consistent with the formula. TOP: Homonuclear Diatomic Molecules 48. Which of the molecular orbital electron configurations given below is correct for F2? a. 1s2 *1s2 2s2 *2s2 2py2 2pz2 2p2 *2py2 *2pz1 b. 1s2 *1s2 2s2 *2s2 2p2 2py2 2pz2 *2py2 *2pz2 *2p1 c. 1s2 *1s2 2s2 *2s2 2py2 2pz2 2p2 *2py2 *2pz2 *2p1 d. 1s2 *1s2 2s2 *2s2 2p2 2py2 2pz2 *2py2 *2pz1 e. 1s2 *1s2 2s2 *2s2 2py2 2p2 2pz2 *2p2 *2py2 *2pz1 ANS: B OBJ: Identify the MO electron diagram consistent with the formula. TOP: Homonuclear Diatomic Molecules
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49. What diatomic molecule and/or ion(s) would have the molecular orbital electron configuration given below? s2 *s2 s2 *s2 2py2 2pz1 a. b. c. d. e.
O2+ and N2 C2 and B2+ N2+ and C2 C2+ and B2 C2 and N2+
ANS: D OBJ: Identify the formulas consistent with the MO electron configuration. TOP: Homonuclear Diatomic Molecules 50. What diatomic molecule and/or ion(s) would have the molecular orbital electron configuration given below? s2 *s2 s2 *s2 p2 2py2 2pz2 *2py2 *2pz2 a. b. c. d. e.
F2 and O22+ O2 and F22+ F2 and O22 F2 and Ne22 O2 and F2
ANS: C OBJ: Identify the formulas consistent with the MO electron configuration. TOP: Homonuclear Diatomic Molecules 51. What diatomic molecule and/or ion(s) would have the molecular orbital electron configuration given below? s2 *s2 s2 *s2 p2 2py2 2pz2 a. b. c. d. e.
C2 and B2 C2 and N2+ B2 and N2+ B22 and N22+ B2 and Be22
ANS: D OBJ: Identify the formulas consistent with the MO electron configuration. TOP: Homonuclear Diatomic Molecules 52. Which response lists all the following diatomic molecules and ions that are paramagnetic? Li2, Be2, B2, C2, N2, N2+, N22+ a. b. c. d. e.
Be2, B2, and N2+ Be2, N2, and N22+ Be2, B2, and N2 Li2, B2, and N2 Li2, C2, and N22+
ANS: A OBJ: Determine the paramagnetic molecules given the molecule formulas. TOP: Homonuclear Diatomic Molecules Whitten 10e
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53. Which response lists all the following diatomic ions that are diamagnetic? B+2, B22+, C22+, C22, O2, O22 a. b. c. d. e.
B22+, C22, and O22 B2+ and B2 C22+, and C22 C22, and O22 B22+, C22+, and O2
ANS: A OBJ: Determine the diamagnetic molecules given the molecule formulas. TOP: Homonuclear Diatomic Molecules 54. Which response lists all the following diatomic molecules and ions that have at least one unpaired electron? Be2, B2, B2+, C2, N2, N2+ a. b. c. d. e.
Be2 and B2 B2+ and C2 B2, B2+, and N2+ B2+ and N2 B2 and N2
ANS: C OBJ: Determine the paramagnetic molecules given the molecule formulas. TOP: Homonuclear Diatomic Molecules 55. What is the bond order for N2? a. 1 b. 2 c. 3 d. 1.5 e. 2.5 ANS: E OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 56. What is the bond order for O2? a. 1 b. 2 c. 3 d. 1.5 e. 2.5 ANS: D OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 57. What is the bond order for B22+? a. 0.5 b. 1 c. 1.5 d. 2 e. zero Whitten 10e
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ANS: E OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 58. What is the bond order for O22? a. 1 b. 1.5 c. 2 d. 2.5 e. zero ANS: A OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 59. What is the bond order for O22+? a. 1 b. 2 c. 2.5 d. 3 e. zero ANS: D OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 60. What is the bond order for B2? a. 1 b. 1.5 c. 2 d. 2.5 e. 3 ANS: B OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules 61. What is the bond order for Ne22+? a. 1 b. 1.5 c. 2 d. 2.5 e. 3 ANS: A OBJ: Determine the bond order given the molecule formula. TOP: Homonuclear Diatomic Molecules
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62. Which response lists only the species that have zero bond order? Li2, Ne2, C2+, He2, F22 a. b. c. d. e.
Ne2, He2, and F22 C2+ Ne2 and He2 Li2 and C2+ Li2 and He2
ANS: A OBJ: Identify the formulas consistent with zero bond order. TOP: Homonuclear Diatomic Molecules 63. Which of the following diatomic species has the highest bond order? a. B2+ b. C2 c. N2 d. O2 e. F2 ANS: C OBJ: Identify the molecule formula consistent with the highest bond order. TOP: Homonuclear Diatomic Molecules 64. Which of the following diatomic species has the highest bond order? a. B2 b. O22 c. O2 d. O22+ e. B22+ ANS: D OBJ: Identify the molecule formula consistent with the highest bond order. TOP: Homonuclear Diatomic Molecules 65. Which of the following diatomic species has the lowest bond order? a. B2+ b. C2 c. N2+ d. O2 e. F2 ANS: A OBJ: Identify the molecule formula consistent with the lowest bond order. TOP: Homonuclear Diatomic Molecules 66. Which of the following diatomic species has a bond order of zero? a. Li2+ b. B2 c. N2 d. O2 e. F22
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ANS: E OBJ: Identify the molecule formula consistent with zero bond order. TOP: Homonuclear Diatomic Molecules 67. What is the bond order for each of the following species and which one would be predicted to be most stable? H2+, H2, H2 bond order H2 H2 H2 0 1 0 0.5 1 1.5 0 1 2 0.5 1 0.5 1.5 1 0.5 +
a. b. c. d. e.
most stable H2 H2 H2 H2 H2+
ANS: D OBJ: Determine the bond order and relative stability of each molecule. TOP: Homonuclear Diatomic Molecules 68. What is the bond order for each of the following species and which one would be predicted to have the shortest bond length? N2, N2, N2+
a. b. c. d. e.
N2 3 3 3 2 3
bond order N2 N2+ 3.5 2.5 2.5 2.5 4 2 3 1 4 2
shortest bond length N2+ N2 N2 N2 N2
ANS: B OBJ: Determine the bond order and relative bond lengths of each molecule. TOP: Homonuclear Diatomic Molecules 69. What is the bond order for each of the following species and which is (are) paramagnetic? B2, B2+, B2
a. b. c. d. e.
B2 1 1 1 1 2
bond order B2+ B2 0.5 1.5 0.5 0.5 0.5 1.5 1.5 1.5 3 1
paramagnetic none B2+ all three B2 B2
ANS: C OBJ: Determine the bond order and unpaired electrons of each molecule. TOP: Homonuclear Diatomic Molecules
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70. What is the bond order for NO? a. 1 b. 1.5 c. 2 d. 2.5 e. 3 ANS: C OBJ: Determine the bond order given the molecule formula. TOP: Heteronuclear Diatomic Molecules 71. Which statement regarding stable heteronuclear diatomic molecules is false? a. The bonding molecular orbitals have more of the character of the more electronegative element than of the less electronegative element. b. The antibonding molecular orbitals have more of the character of the more electropositive element than of the more electronegative element. c. All have bond orders greater than zero. d. Their molecular orbital diagrams are more symmetrical than those of homonuclear diatomic molecules. e. The greater the difference in energy between two overlapping atomic orbitals, the more polar is the bond resulting from the electrons occupying that bonding molecular orbital. ANS: D OBJ: Describe bonding in heteronuclear diatomics. TOP: Heteronuclear Diatomic Molecules 72. Which of the following statements about nitrogen oxide, NO, is false? a. Nitrogen oxide is isoelectronic with the N2 ion. b. Nitrogen oxide has a bond order of 2.5. c. The bonding MOs of NO have more oxygen-like atomic orbital character. d. The antibonding MOs of NO have more nitrogen-like atomic orbital character. e. Nitrogen oxide is a very unstable molecule. ANS: E OBJ: Apply MO theory to a heteronuclear diatomic. TOP: Heteronuclear Diatomic Molecules 73. Draw the molecular orbital diagram for NO. Which of the following statements is false? a. The total number of electrons in the *2p molecular orbitals is 1. b. The molecule is paramagnetic. c. The bond order is 2.5 d. The atomic orbitals for oxygen are higher in energy than those of nitrogen. e. The bonding molecular orbitals have more oxygen-like atomic orbital character. ANS: D DIF: Harder Question OBJ: Apply MO theory to a heteronuclear diatomic. TOP: Heteronuclear Diatomic Molecules 74. What is the bond order for CN+? a. 1 b. 1.5 c. 2 d. 2.5 e. 3
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ANS: C OBJ: Determine the bond order given the molecule formula. TOP: Heteronuclear Diatomic Molecules 75. What is the bond order for NO+? a. 1 b. 1.5 c. 2 d. 2.5 e. 3 ANS: E OBJ: Determine the bond order given the molecule formula. TOP: Heteronuclear Diatomic Molecules 76. What is the bond order for HF? a. 0.5 b. 1 c. 1.5 d. 2 e. 2.5 ANS: A DIF: Harder Question OBJ: Determine the bond order given the molecule formula. TOP: Heteronuclear Diatomic Molecules 77. What is the most stable heteronuclear diatomic species? a. CN b. CN c. NO d. BO e. HF ANS: B OBJ: Identify the most stable heteronuclear diatomic. TOP: Heteronuclear Diatomic Molecules 78. Which statement concerning the carbonate ion, CO32, is false? a. Valence bond theory describes the ion in terms of 3 contributing resonance structures. b. All of the carbonoxygen bonds in the ion have the same bond length and bond energy. c. The carbon-oxygen bonds in the ion are intermediate in length and energy between those of CO and C=O bonds. d. The bonding in the isoelectronic nitrate ion, NO3, can be described in a manner similar to the carbonate ion. e. MO terminology describes the formation of a delocalized bonding pi molecular orbital system extending above the plane of the sigma system of the carbonate ion and an antibonding pi molecular orbital system extending below the plane of the sigma system. ANS: E OBJ: Apply MO and VB theory to the given molecule. TOP: Delocalization and the Shapes of Molecular Orbitals
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79. Which statement concerning the benzene molecule, C6H6, is false? a. Valence bond theory describes the molecule in terms of 3 resonance structures. b. All six of the carboncarbon bonds have the same length. c. The carboncarbon bond lengths are intermediate between those for single and double bonds. d. The entire benzene molecule is planar. e. The valence bond description involves sp2 hybridization at each carbon atom. ANS: A OBJ: Apply MO and VB theory to the given molecule. TOP: Delocalization and the Shapes of Molecular Orbitals
Dynamic Questions 80. Given the molecular orbital diagram for dilithium (Li2) below, what would be the bond order
of Li2?
a. b. c. 1 d. 0 e. 2 ANS: A DIF: moderate OBJ: Determine the bond order given the MO diagram. TOP: Molecular Orbital Energy Level Diagrams
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81. Identify the molecule or ion with one or more unpaired electrons, given the molecular orbital
diagrams for H2-Ne2 below.
a. b. c. d. e.
F2 C2 O22O22+ F2+
ANS: E DIF: moderate OBJ: Determine if a molecule or ion is diamagnetic or paramagnetic given the MO diagram. TOP: Molecular Orbital Energy Level Diagrams 82. Identify the molecule or ion with the lowest bond order. a. b. c. d. e.
N2 C2 H2N2O22+
ANS: C DIF: moderate OBJ: Identify the molecule or ion with the lowest or highest bond order. TOP: Molecular Orbital Energy Level Diagrams 83. What is the bond order for a molecule with 6 electrons in bonding molecular orbitals and 2 electrons in antibonding molecular orbitals? a. 4 b. 3 c. 8 d. 2 e. 4
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ANS: D OBJ: Determine the bond order given the number of bonding and antibonding electrons. TOP: Bond Order and Bond Stability 84. What is the bond order of He2? a. b. c. 1 d. 0 e. 2 ANS: A DIF: moderate OBJ: Determine the bond order given the diatomic molecule or ion. TOP: Bond Order and Bond Stability 85. What is the bond order of Ne2? a. b. c. 1 d. 0 e. 2 ANS: C DIF: moderate OBJ: Determine the bond order given diatomic molecule or ion. TOP: Bond Order and Bond Stability 86. Identify the molecule or ion with a bond order of zero. a. b. c. d. e.
B22+ B2+ B2 F2+ O2+
ANS: A DIF: moderate OBJ: Identify the molecule or ion with a bond order of zero. TOP: Bond Order and Bond Stability 87. Identify the molecule or ion with the longest bond length. a. b. c. d. e.
O2 O2+ O2O22O22+
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ANS: D DIF: moderate OBJ: Identify the molecule or ion with the lowest or highest bond length. TOP: Bond Order and Bond Stability 88. Identify the molecule with the shortest bond length. a. b. c. d. e.
O2 C2 B2 F2 N2
ANS: E DIF: moderate OBJ: Identify the molecule with the lowest or highest bond length. TOP: Bond Order and Bond Stability 89. Identify the molecule or ion with the longest bond length. a. b. c. d. e.
F2+ F2 F2F22+ All bond lengths are equivalent.
ANS: C DIF: moderate OBJ: Identify the molecule or ion with the lowest or highest bond length. TOP: Bond Order and Bond Stability 90. What is the bond order for the carbon-nitrogen bond in acetonitrile, CH3CN? a. 0.5 b. 1.0 c. 1.5 d. 2.0 e. 3.0 ANS: E OBJ: Determine the bond order given the formula. TOP: Bond Order and Bond Stability 91. What is the bond order of the C-O bonds in the carbonate ion, CO32-? a. 0.5 b. 1.0 c. 1.3 d. 1.5 e. 2.0 ANS: C OBJ: Determine the bond order given the molecule formula. TOP: Bond Order and Bond Stability 92. What is the bond order in the Li2+ molecular ion? a. 0 b. 0.5 c. 1.0
d. 1.5
e. 2.0
ANS: B OBJ: Determine the bond order given the formula. TOP: Bond Order and Bond Stability
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93. Use molecular orbital diagrams to predict which of the following species is paramagnetic. a. Li2 b. F2 c. O2 d. N2 e. Be2 ANS: C OBJ: Identify the paramagnetic species. TOP: Molecular Orbitals 94. Use molecular orbital diagrams to predict which of the following species is paramagnetic. a. Ne22+ b. He2+ c. O22d. Cl22+ e. B22+ ANS: B OBJ: Identify the paramagnetic species. TOP: Molecular Orbitals CONCEPTUAL 1. Describe the phenomena of loud crowd noise at a sporting event in terms of wave interference. OBJ: Describe crowd noise in terms of overlapping sound waves. TOP: Constructive and destructive interference. 2. If antibonding orbitals are destabilizing for the bond in the molecule, why do electrons occupy them? OBJ: Explain how MO diagrams are filled with electrons. TOP: Molecular Orbitals | Molecular Orbital Energy Level Diagrams 3. Explain how Hund's rule is an important consideration in confirming that O2 is a paramagnetic substance. OBJ: Explain how MO diagrams are filled with electrons. TOP: Molecular Orbital Energy Level Diagrams 4. Confirm that fractional bond orders exist in species that have odd numbers of electrons like NO and the superoxide ion, O2. OBJ: Determine the MO diagrams of odd electron diatomics. TOP: Molecular Orbital Energy Level Diagrams 5. Using Molecular Orbital theory, explain why there is no physical evidence of double bonds in the benzene molecule. OBJ: Explain the lack of physical evidence regarding the double bond in benzene. TOP: Delocalization and the Shapes of Molecular Orbitals
Chapter 10—Reactions in Aqueous Solutions I: Acids, Bases, and Salts MULTIPLE CHOICE 1. Which of the following is not a common property of most protonic acids? a. They have a bitter taste. b. They change the colors of many indicators (highly colored dyes). c. Nonoxidizing acids react with metals more active than hydrogen to liberate H2. d. They react with metal hydroxides and metal oxides to form salts and water. e. They react with salts of more volatile acids to form the more volatile acid and a new salt. Whitten 10e
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ANS: A OBJ: Identify the properties of acids. TOP: Properties of Aqueous Solutions of Acids and Bases 2. The following describe properties of substances. Which one is not a property of acids? a. They have a sour taste. b. They react with metal oxides to form salts and water. c. They react with other acids to form salts and water. d. Their aqueous solutions conduct an electric current. e. They react with active metals to liberate H2. ANS: C OBJ: Identify the properties of acids. TOP: Properties of Aqueous Solutions of Acids and Bases 3. Which of the following is not a common property of aqueous solutions of most bases? a. They have a bitter taste. b. They have a slippery feeling. c. They change the colors of many indicators. d. They react with protonic acids to form salts and stronger bases. e. Their aqueous solutions conduct an electric current. ANS: D OBJ: Identify the properties of bases. TOP: Properties of Aqueous Solutions of Acids and Bases 4. Which of these common substances is not acidic? a. vinegar b. Drano c. "digestive juice" d. Coca-Cola e. car battery solution ANS: B OBJ: Identify the non-acidic substance. TOP: Properties of Aqueous Solutions of Acids and Bases
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5. Which of these common substances in not basic? a. Drano b. soap c. Clorox d. lemon juice e. oven cleaner ANS: D OBJ: Identify the non-basic substance. TOP: Properties of Aqueous Solutions of Acids and Bases 6. According to the Arrhenius theory, which of the following is an acid? a. NH3 b. CH4 c. HCl d. H2 e. NaOH ANS: C OBJ: Identify the formula of an Arrhenius acid. TOP: The Arrhenius Theory 7. Which statement is not consistent with the Arrhenius theory of acid-base reactions? a. An acid is a substance that contains hydrogen and produces H+ in aqueous solution. b. A base is a substance that contains the OH group and produces OH in aqueous solution. c. Ammonia is classified as a base. d. Neutralization is the combination of H+ ions with OH ions to form H2O. e. The Arrhenius theory satisfactorily explained the reactions of protonic acids with metal hydroxides. ANS: C OBJ: Identify the components of the Arrhenius theory. TOP: The Arrhenius Theory 8. According to the Arrhenius theory, which of the following is a base? a. CsOH b. HOOH c. CH3OH d. HCOOH e. CH3COOH ANS: A OBJ: Identify the formula of an Arrhenius base. TOP: The Arrhenius Theory 9. Which statement concerning the hydrated hydrogen ion is incorrect? a. Although we often represent hydrogen ions as bare protons (H+), we know they are hydrated in aqueous solutions. b. It is now known that hydrogen ions exist as H+(H2O)n where n is a small integer. c. The value of n for H+(H2O)n can be calculated for almost all solutions. d. The hydrated hydrogen ion is the species that gives aqueous solutions of acids their characteristic acidic properties. e. The hydrogen ion is often represented in equations by H+(aq), H3O+, or even H+.
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ANS: C OBJ: Identify what is known about the hydrated hydrogen ion. TOP: The Hydronium Ion (Hydrated Hydrogen Ion) 10. What is the basis for referring to "H+" as a proton? a. The Arrhenius definition of an acid b. The Brønsted-Lowry definition of an acid c. The Lewis definition of an acid d. H+ exists as a bare proton e. None of these ANS: D OBJ: Equate the hydrogen ion and the proton. TOP: The Hydronium Ion (Hydrated Hydrogen Ion) 11. According to the Brønsted-Lowry theory, a base is defined as ____. a. an electron pair acceptor b. a proton acceptor c. an electron pair donor d. a proton donor e. any species that can produce hydroxide ions in aqueous solution ANS: B OBJ: Define Brønsted-Lowry base. TOP: The Brønsted-Lowry Theory 12. A Brønsted-Lowry acid is defined as a ____. a. species that donates a proton b. species that accepts a proton c. species that accepts a share in an electron pair d. species that makes available a share in an electron pair e. species that produces H+ ions in aqueous solution ANS: A OBJ: Define Brønsted-Lowry acid. TOP: The Brønsted-Lowry Theory 13. Which of the following can be a Brønsted-Lowry acid? a. AlCl3 b. CH4 c. NaOH d. H2O e. H2 ANS: D OBJ: Identify the formula of a Brønsted-Lowry acid. TOP: The Brønsted-Lowry Theory 14. Which one of the following could not be a Brønsted-Lowry acid? a. H2O b. HN3 c. H3O+ d. NH4+ e. BF3
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ANS: E OBJ: Identify the formula of the species that cannot act as a Brønsted-Lowry acid. TOP: The Brønsted-Lowry Theory 15. Which one of the following species could not react as a Brønsted-Lowry acid? a. HCN b. H2S c. CaO d. NH3 e. CH3COOH ANS: C OBJ: Identify the formula of the species that cannot act as a Brønsted-Lowry acid. TOP: The Brønsted-Lowry Theory 16. Which one of the following species could not react as a Brønsted-Lowry base? a. NH4+ b. NH2 c. CN d. F e. CH3COO ANS: A OBJ: Identify the formula of the species that cannot act as a Brønsted-Lowry base. TOP: The Brønsted-Lowry Theory 17. Which one of the following species could not react as a Brønsted-Lowry base? a. H2S b. PH3 c. NH3 d. CH4 e. H2O ANS: D OBJ: Identify the formula of the species that cannot act as a Brønsted-Lowry base. TOP: The Brønsted-Lowry Theory 18. Which cannot be both a Brønsted-Lowry acid and a Brønsted-Lowry base? a. H2O b. HCO3 c. H2PO4 d. HPO42 e. PO43 ANS: E OBJ: Identify the formula of the species that cannot act as a Brønsted-Lowry acid and base. TOP: The Brønsted-Lowry Theory
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19. In the equation HF + H2O a. b. c. d. e.
H3O+ + F
H2O is a base, and HF is its conjugate acid. H2O is an acid, and HF is the conjugate base. HF is an acid, and F is its conjugate base. HF is a base, and H3O+ is its conjugate acid. HF is a base, and F is its conjugate acid.
ANS: C OBJ: Identify the reactant acid and base, and their conjugates in a chemical reaction. TOP: The Brønsted-Lowry Theory 20. In the equation HF + H2O a. b. c. d. e.
H3O+ + F
H3O+ acts as a proton acceptor. F acts as a proton acceptor. H2O is a stronger acid than HF. HF is completely ionized in dilute aqueous solution. None of these.
ANS: B DIF: Harder Question OBJ: Identify the proton donors and acceptors in a chemical reaction. | Identify the stronger acid. | Understand the meaning of the double arrow. TOP: The Brønsted-Lowry Theory 21. Which one of the following statements is true? CH3NH2 + H2O CH3NH3+ methylamine water methylammonium ion a. b. c. d. e.
+ OH hydroxide ion
CH3NH2 is the conjugate base of H2O. CH3NH3+ is the conjugate base of CH3NH2. H2O is the conjugate acid of OH. OH is the conjugate acid of H2O. There are no conjugate acid-base pairs.
ANS: C OBJ: Identify the reactant acid and base, and their conjugates in a chemical reaction. TOP: The Brønsted-Lowry Theory 22. Which of the following does not represent a conjugate acid-base pair? a. H3O+ / H2O b. H3O+ / OH c. HCl / Cl d. H2SO3 / HSO3 e. NH4+ / NH3 ANS: B OBJ: Identify the conjugate acid-base pairs. TOP: The Brønsted-Lowry Theory
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23. Which one of the following pairs of acids and conjugate bases is incorrectly labeled or incorrectly matched?
a. b. c. d. e.
Acid / Conjugate Base HF / F HClO / ClO H2O / OH NH4+ / NH2 H3O+ / H2O
ANS: D OBJ: Identify the conjugate acid-base pairs. TOP: The Brønsted-Lowry Theory 24. Which one of the following pairs of acids and conjugate bases is incorrectly labeled or incorrectly matched?
a. b. c. d. e.
Acid / Conjugate Base water / hydroxide sulfuric acid / sulfate perchloric acid / perchlorate nitric acid / nitrate hydrobromic acid / bromide
ANS: B OBJ: Identify the conjugate acid-base pairs. TOP: The Brønsted-Lowry Theory 25. The following acids are listed in order of decreasing acid strength in water. HI > HNO2 > CH3COOH > HClO > HCN According to Brønsted-Lowry theory, which of the following anions is the weakest base? a. I b. NO2 c. CH3COO d. ClO e. CN ANS: A OBJ: Use relative acidity to determine the weakest conjugate base. TOP: The Brønsted-Lowry Theory 26. Which statement concerning the autoionization (self-ionization) of water is false? 2H2O H3O+(aq) + OH(aq) a. b. c. d. e.
This reaction is an acid-base reaction according to the Brønsted-Lowry theory. Water is amphiprotic. A H2O molecule may react as an acid by donating a proton. In this reaction H3O+ and OH are a conjugate acid-base pair. A H2O molecule may react as a base by accepting a proton.
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ANS: D OBJ: Apply the Brønsted-Lowry theory to the description of the autoionization of water. | Define amphiprotic. TOP: The Autoionization of Water 27. Which of the following compounds will dissolve in (by reaction with) hydrochloric acid and will also dissolve in (by reaction with) an excess of 6 M NaOH solution? a. KOH b. Mg(OH)2 c. Ba(OH)2 d. Sn(OH)2 e. Sr(OH)2 ANS: D OBJ: Identify the species that will react with an acid or a base. TOP: Amphoterism 28. If a compound is able to react as either an acid or a base, it is said to be which of these? a. autoionized b. amphoteric c. hydrated d. balanced e. neutralized ANS: B OBJ: Define amphoteric. TOP: Amphoterism 29. Which one of the following is an amphoteric metal hydroxide? a. KOH b. Ba(OH)2 c. Be(OH)2 d. LiOH e. Mg(OH)2 ANS: C OBJ: Identify the species that will react with an acid or a base. TOP: Amphoterism 30. Which one of the following hydroxides is amphoteric? a. Ca(OH)2 b. Ba(OH)2 c. Fe(OH)3 d. NaOH e. Zn(OH)2 ANS: E OBJ: Identify the species that will react with an acid or a base. TOP: Amphoterism
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31. Which of the following is not an amphoteric metal hydroxide? a. La(OH)3 b. Be(OH)2 c. Cr(OH)3 d. Al(OH)3 e. Zn(OH)2 ANS: A DIF: Harder Question OBJ: Identify the species that will not react with both an acid and base. TOP: Amphoterism 32. Which one of the following hydroxides is not amphoteric? a. Cr(OH)3 b. Sn(OH)2 c. Zn(OH)2 d. Ca(OH)2 e. Al(OH)3 ANS: D OBJ: Identify the species that will not react with both an acid and base. TOP: Amphoterism 33. Write the net ionic equation for the reaction of aluminum hydroxide with an excess of concentrated sodium hydroxide solution. The complex ion that is formed in this reaction has ____ hydroxide ions bonded to each aluminum, and the charge on the complex ion is ____. a. one; 2+ b. two; 1+ c. three; 0 d. four; 1 e. four; 4+ ANS: D OBJ: Determine the product formed from reaction of an amphoteric hydroxide with base. TOP: Amphoterism 34. Write the net ionic equation for the reaction of beryllium hydroxide with an excess of concentrated sodium hydroxide solution. The complex ion that is formed in this reaction has ____ hydroxide ions bonded to each beryllium, and the charge on the complex ion is ____. a. one; 2+ b. two; 1+ c. three; 0 d. four; 1 e. four; 2 ANS: E OBJ: Determine the product formed from reaction of an amphoteric hydroxide with base. TOP: Amphoterism 35. Which one of the following is a weak acid? a. H2SO4 b. HClO c. HCl d. HBr e. HI Whitten 10e
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ANS: B OBJ: Identify the weak acid. TOP: Strengths of Acids 36. Which one of the following is a weak acid? a. HNO3 b. H3PO4 c. HClO3 d. HClO4 e. HI ANS: B OBJ: Identify the weak acid. TOP: Strengths of Acids 37. Which one of the following is not a strong acid? a. HBr b. HF c. HI d. HCl e. HClO3 ANS: B OBJ: Identify the weak acid. TOP: Strengths of Acids 38. Which of the following is the strongest acid? a. HF b. HCl c. HBr d. HI e. CH3COOH ANS: D OBJ: Identify the strongest acid. TOP: Strengths of Acids 39. Which of the following is the strongest acid? a. NH3 b. HNO2 c. HNO3 d. H2NNH2 e. NH4+ ANS: C OBJ: Identify the strong acid. TOP: Strengths of Acids 40. Which of the following is the weakest acid? a. HCl b. HClO c. HClO2 d. HClO3 e. HClO4
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ANS: B OBJ: Identify the weakest acid. TOP: Strengths of Acids 41. Which response includes all the acids listed below that are strong acids, and no weak acids? H2SO4, HI, HF, H3PO4, HNO3 a. b. c. d. e.
HI, HF, HNO3 H2SO4, HNO3 H2SO4, HI, HNO3 H2SO4, H3PO4, HNO3 another one or another combination
ANS: C OBJ: Identify the strong acids. TOP: Strengths of Acids 42. Which response includes all the following compounds that are weak acids, and no strong acids? H2SO4, HNO2, H2SO3, HF, HI a. b. c. d. e.
H2SO4, HI H2SO4, H2SO3 HNO2, HF HNO2, H2SO3, HF HNO2, H2SO3
ANS: D OBJ: Identify the weak acids. TOP: Strengths of Acids 43. Which of the following can serve as a leveling solvent for both hydrochloric and hydrobromic acids? a. HI b. H2O c. H3O+ d. there are no leveling solvents for HCl and HBr e. any solvent will be a leveling solvent for HCl and HBr ANS: B OBJ: Identify the solvent that levels strong acids. TOP: Strengths of Acids 44. Which of the following statements about sulfuric acid is false? a. It is a strong acid. b. Its conjugate base is HSO4. c. Its conjugate base is a strong base. d. It is a stronger acid than H2SO3. e. It is an acid according to Arrhenius Theory. ANS: C OBJ: Use Arrhenius and Brønsted-Lowry theories to describe an acid. TOP: Strengths of Acids
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45. Arrange the following in order of increasing acid strength. H2O, H2Se, H2Te, H2S
a. b. c. d. e.
H2O < H2Te < H2Se < H2S H2Se < H2Te < H2O < H2S H2S < H2Se < H2Te < H2O H2O < H2S < H2Se < H2Te H2Se < H2Te < H2S < H2O
ANS: D OBJ: Arrange the species in order of increasing acidity. TOP: Strengths of Acids 46. Which one of the following pairs of acids is incorrectly listed?
a. b. c. d. e.
Stronger Acid / Weaker Acid HClO / HClO2 HNO3 / HNO2 H2SO4 / H2SO3 H2SO3 / H2SeO3 HClO4 / HIO4
ANS: A OBJ: Arrange each pair in order of decreasing acidity. TOP: Strengths of Acids 47. Which indication of relative acid strength is incorrect? a. HNO3 > HNO2 b. HI > HF c. H2PO4 > HPO42 d. HClO3 > HBrO3 e. HClO > HCl ANS: E OBJ: Arrange each pair in order of decreasing acidity. TOP: Strengths of Acids 48. Which statement about H2O is false? a. The hydronium ion is the strongest acid that can exist in aqueous solution. b. All acids stronger than H3O+(aq) react completely in water to produce H3O+. c. The hydroxide ion is the strongest base that can exist in aqueous solution. d. Bases stronger than H2O react completely in water to produce H3O+. e. H2O is a leveling solvent for all bases stronger than hydroxide. ANS: D DIF: Harder Question OBJ: Define the acid-base chemistry of water. TOP: Strengths of Acids
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49. Four of the following pairs of acids list the weaker acid at the left and the stronger acid at the right. Which pair is reversed?
a. b. c. d. e.
Weaker Acid / Stronger Acid HIO3 / HClO3 HNO2 / HNO3 H3PO4 / HNO3 H3PO4 / H3AsO4 HBrO3 / HClO3
ANS: D OBJ: Arrange each pair in order of increasing acidity. TOP: Strengths of Acids 50. Which of these anions is the strongest base, according to the Brønsted-Lowry theory? a. hypochlorite b. chlorite c. chlorate d. perchlorate e. they are all equal in base strength ANS: A OBJ: Identify the strongest Brønsted-Lowry base. TOP: Strengths of Acids 51. Why is HI a stronger acid than HCl? a. Because I is more electronegative than Cl. b. Because Cl is more electronegative than I. c. The bond strength of HCl is greater than the bond strength of HI. d. The bond strength of HI is greater than the bond strength of HCl. e. HI is not a stronger acid than HCl. ANS: C OBJ: Understand the relationship between bond strength and acidity. TOP: Strengths of Acids 52. According to the Brønsted-Lowry theory, which of these anions is the strongest base? a. NO3 b. Cl c. CN d. ClO4 e. HSO4 ANS: C OBJ: Identify the strongest Brønsted-Lowry base. TOP: Strengths of Acids 53. According to the Brønsted-Lowry theory, which of these anions is the weakest base? a. Br b. ClO c. NO2 d. F e. CH3COO
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ANS: A OBJ: Identify the weakest Brønsted-Lowry base. TOP: Strengths of Acids 54. According to the Brønsted-Lowry theory, which of these acids would have the weakest conjugate base? a. HBrO3 b. HNO2 c. HClO4 d. HClO2 e. HF ANS: C DIF: Harder Question OBJ: Identify the strong acid. TOP: Strengths of Acids 55. Which one of the following is a soluble, strong base? a. Cu(OH)2 b. Fe(OH)3 c. Al(OH)3 d. Sr(OH)2 e. Mg(OH)2 ANS: D OBJ: Identify the strong base. TOP: Acid-Base Reactions in Aqueous Solutions 56. Which one of the following is a soluble, strong base? a. CsOH b. Cu(OH)2 c. Fe(OH)3 d. Mn(OH)2 e. Al(OH)3 ANS: A OBJ: Identify the strong base. TOP: Acid-Base Reactions in Aqueous Solutions 57. Which one of the following compounds is not a soluble, strong base? a. Ba(OH)2 b. Ca(OH)2 c. Co(OH)2 d. RbOH e. KOH ANS: C OBJ: Identify the insoluble base. TOP: Acid-Base Reactions in Aqueous Solutions
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58. Which one of the following is not a soluble, strong base? a. NaOH b. KOH c. RbOH d. CsOH e. NH2OH ANS: E OBJ: Identify the insoluble base. TOP: Acid-Base Reactions in Aqueous Solutions 59. Which one of the following is not a soluble, strong base? a. KOH b. CsOH c. NH3 d. Ca(OH)2 e. Sr(OH)2 ANS: C OBJ: Identify the weak base. TOP: Acid-Base Reactions in Aqueous Solutions 60. Which response includes all of the following that are insoluble bases, and no others? LiOH, Cu(OH)2, Be(OH)2, Ba(OH)2, KOH a. b. c. d. e.
LiOH, Ba(OH)2 Cu(OH)2, KOH, Ba(OH)2 LiOH, Be(OH)2 Cu(OH)2, Ba(OH)2 another one or another combination
ANS: E OBJ: Identify the insoluble bases. TOP: Acid-Base Reactions in Aqueous Solutions 61. Which one of the following compounds is incorrectly classified?
a. b. c. d. e.
Compound / Classification (C2H5)2NH / weak base HCN / weak acid Sr(OH)2 / soluble, strong base Cr(OH)3 / insoluble base Fe(OH)2 / soluble base
ANS: E OBJ: Identify the incorrect acid-base classification. TOP: Acid-Base Reactions in Aqueous Solutions 62. Which one of the following compounds is not a salt? a. K2SO4 b. HClO4 c. CaCrO4 d. CoCl2 e. NaMnO4
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ANS: B OBJ: Identify the compound that is not a salt. TOP: Acid-Base Reactions in Aqueous Solutions 63. Which one of the following salts is insoluble in water? a. MgCO3 b. (NH4)2SO4 c. KCH3COO d. Cu(NO3)2 e. Fe2(SO4)3 ANS: A OBJ: Identify the insoluble compound. TOP: Acid-Base Reactions in Aqueous Solutions 64. Which one of the following salts is insoluble in water? a. AgNO3 b. KI c. NH4Cl d. PbS e. NaBr ANS: D OBJ: Identify the insoluble compound. TOP: Acid-Base Reactions in Aqueous Solutions 65. Write the balanced formula unit equation for the reaction of hydrobromic acid with magnesium hydroxide. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 3 d. 4 e. 5 ANS: A OBJ: Write the balanced acid-base reaction given the reactants. | Sum the coefficients. TOP: Acid-Base Reactions in Aqueous Solutions 66. Write the balanced formula unit equation for the complete neutralization of dilute sulfuric acid with sodium hydroxide in aqueous solution. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 8 c. 9 d. 4 e. 5 ANS: A OBJ: Write a balanced chemical equation given the reactants. | Sum the coefficients. TOP: Acid-Base Reactions in Aqueous Solutions
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67. Write the balanced formula unit equation for the reaction of iron(II) hydroxide with hydrobromic acid. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 7 c. 8 d. 4 e. 5 ANS: A OBJ: Write a balanced chemical equation given the reactants. | Sum the coefficients. TOP: Acid-Base Reactions in Aqueous Solutions 68. Write the balanced net ionic equation for the complete neutralization of chromium(III) hydroxide with sulfuric acid. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 8 b. 11 c. 16 d. 18 e. 22 ANS: A DIF: Harder Question OBJ: Write a balanced net ionic equation given the reactants. | Sum the coefficients. TOP: Acid-Base Reactions in Aqueous Solutions 69. Write the net ionic equation for the complete neutralization of HBr by Ca(OH)2. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 6 b. 8 c. 3 d. 4 e. 5 ANS: C OBJ: Write a balanced net ionic equation given the reactants. | Sum the coefficients. TOP: Acid-Base Reactions in Aqueous Solutions 70. Consider the complete neutralization reactions between the following acid-base pairs in dilute aqueous solutions. Which one of the reactions produces insoluble salts? a. CH3COOH + NaOH b. HNO3 + Mg(OH)2 c. H3PO4 + Ca(OH)2 d. HCl + KOH e. H2SO4 + Sr(OH)2 ANS: C OBJ: Identify the reactants which produce an insoluble salt. TOP: Acid-Base Reactions in Aqueous Solutions
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71. For the complete neutralization reactions between the following pairs of acid and bases, which pair is a soluble, strong base and a weak acid that react to form a soluble salt? a. Ca(OH)2, HNO3 b. KOH, H3PO4 c. NH3, HF d. Ba(OH)2, H2CO3 e. Fe(OH)2, H2S ANS: B OBJ: Identify the strong base-weak acid pair. TOP: Acid-Base Reactions in Aqueous Solutions 72. For the complete neutralization reactions between the following pairs of acid and bases, which pair is a soluble, strong base and a weak acid that react to form an insoluble salt? a. Ca(OH)2, HNO3 b. KOH, H3PO4 c. NH3, HF d. Ba(OH)2, H2CO3 e. Fe(OH)2, H2S ANS: D OBJ: Identify the strong base-weak acid pair. TOP: Acid-Base Reactions in Aqueous Solutions 73. For the complete neutralization reactions between the following pairs of acid and bases, which pair is an insoluble base and a weak acid that react to form an insoluble salt? a. Ca(OH)2, HNO3 b. KOH, H3PO4 c. NH3, HF d. Ba(OH)2, H2CO3 e. Pb(OH)2, H2S ANS: E OBJ: Identify the insoluble base-weak acid pair. TOP: Acid-Base Reactions in Aqueous Solutions 74. For which one of the pairs of acids and bases does the following represent the net ionic equation? H3O+ + OH 2H2O a. b. c. d. e.
NaOH, HBr CH3COOH, Ca(OH)2 HNO3, Mg(OH)2 CH3COOH, Cu(OH)2 CH3COOH, Cr(OH)3
ANS: A OBJ: Identify the acid-base pair consistent with the given net ionic equation. TOP: Acid-Base Reactions in Aqueous Solutions
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75. For which one of the pairs of acid and bases does the following represent the correct net ionic equation? CH3COOH + OH CH3COO + H2O a. b. c. d. e.
NaOH, HBr CH3COOH, Ca(OH)2 HNO3, Mg(OH)2 CH3COOH, Cu(OH)2 CH3COOH, Cr(OH)3
ANS: B OBJ: Identify the acid-base pair consistent with the given net ionic equation. TOP: Acid-Base Reactions in Aqueous Solutions 76. Which pair of acids would each react with barium hydroxide and have the net ionic equation: H+ + OH H2O a. b. c. d. e.
HCl and HNO2 HBr and HF HCl and HNO3 HNO3 and H2CO3 HClO4 and H2SO4
ANS: C OBJ: Identify the pair of acids consistent with the given net ionic equation. TOP: Acid-Base Reactions in Aqueous Solutions 77. Which of the following reactions is the net ionic equation for the acid-base reaction between H2CO3 and Sr(OH)2? a. H2CO3 + Sr2+ + 2OH SrCO3 + 2H2O b. H3O+ + OH 2H2O c. 2H3O+ + Sr2+ + 2OH Sr2+ + 4H2O d. H2CO3 + 2OH 2H2O + CO32 e. H2CO3 + Sr(OH)2 2H2O + Sr2+ + CO32 ANS: A OBJ: Identify the net ionic reaction consistent with the given reactants. TOP: Acid-Base Reactions in Aqueous Solutions 78. Suppose 1 mole of hydrobromic acid is dissolved in 1 liter of water. List the following species in order of decreasing concentration: HBr, H2O, Br-, H3O+ a. b. c. d. e.
HBr, H2O, Br, H3O+ HBr, H3O+, H2O, Br H3O+, H2O, Br, HBr H2O, H3O+, Br, HBr H3O+, Br, H2O, HBr
ANS: D OBJ: Arrange the components of an acidic solution in order of concentration. TOP: Acid-Base Reactions in Aqueous Solutions
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79. Suppose 1 mole of hydrocyanic acid is dissolved in 1 liter of water. List the following species in order of decreasing concentration: HCN, H2O, CN, H3O+ a. b. c. d. e.
HCN, H2O, CN, H3O+ HCN, H3O+, H2O, CN H3O+, H2O, CN, HCN H2O, HCN, H3O+, CN H3O+, CN, H2O, HCN
ANS: D OBJ: Arrange the components of an acidic solution in order of concentration. TOP: Acid-Base Reactions in Aqueous Solutions 80. Which response gives all of the members of the following list that are acidic salts and none that are not acidic salts? KH2PO4, K2HPO4, K3PO4, NaHCO3, LiOH, LiH a. b. c. d. e.
KH2PO4, K2HPO4, LiH KH2PO4, NaHCO3, LiOH K3PO4, LiH KH2PO4, K2HPO4, NaHCO3 KH2PO4, K2HPO4, NaHCO3, LiH
ANS: D OBJ: Identify the acidic salts. TOP: Acidic Salts and Basic Salts 81. Which response gives all of the members of the following list that are basic salts and none that are not basic salts? Al(OH)Cl2, Al(OH)2Cl, AlCl3, Ca(OH)Cl, CaCl22H2O a. b. c. d. e.
Al(OH)Cl2, Al(OH)2Cl, AlCl3 Al(OH)Cl2, Al(OH)2Cl, Ca(OH)Cl Al(OH)2Cl, CaCl22H2O Al(OH)Cl2, Ca(OH)Cl Al(OH)Cl2, Al(OH)2Cl, Ca(OH)Cl, CaCl22H2O
ANS: B OBJ: Identify the basic salts. TOP: Acidic Salts and Basic Salts 82. Which of the following is a normal salt? a. Na3PO4 b. NaOH c. NaHCO3 d. NaHSO4 e. all of these are normal salts ANS: A OBJ: Identify the "normal" salt. TOP: Acidic Salts and Basic Salts
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83. According to the Lewis theory, a base ____. a. is a proton acceptor b. is a proton donor c. makes available a share in a pair of electrons d. is any compound that contains electron pairs e. accepts a share in a pair of electrons ANS: C OBJ: Define a Lewis base. TOP: The Lewis Theory 84. Neutralization, according to the Lewis theory, involves ____. a. proton transfer b. the formation of a gas c. the formation of an ionic solid d. the formation of a coordinate covalent bond e. the combination of a hydrogen ion with a hydroxide ion to form water ANS: D OBJ: Define the Lewis theory view of neutralization. TOP: The Lewis Theory 85. Examine the reaction below and classify it. FeBr3 + Br FeBr4 a. b. c. d. e.
single displacement combustion decomposition acid-base oxidation-reduction
ANS: D OBJ: Classify the given chemical reaction. TOP: The Lewis Theory 86. According to the Lewis theory, which one of the following compounds would be expected to react as a Lewis acid, but not as a Lewis base? a. BCl3 b. NH3 c. PH3 d. H2O e. all of these ANS: A OBJ: Identify the species that acts only as a Lewis acid. TOP: The Lewis Theory 87. According to the Lewis theory, which one of the following species would be expected to react as a Lewis base, but not as a Lewis acid? a. BF3 b. F c. AlBr3 d. SnCl4 e. H+
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ANS: B OBJ: Identify the species that acts only as a Lewis base. TOP: The Lewis Theory 88. In the following reaction, the ZnCl2 functions as a(n) ____. ZnCl2 + CH3OCH3 (CH3)2O:ZnCl2 a. b. c. d. e.
Brønsted-Lowry acid Brønsted-Lowry base Arrhenius base Lewis acid Lewis base
ANS: D OBJ: Classify the role of a reactant given the chemical reaction. TOP: The Lewis Theory 89. In the following reaction, the Cl functions as a(n) ____. AlCl3 + Cl AlCl4 a. b. c. d. e.
Brønsted-Lowry acid Brønsted-Lowry base Arrhenius base Lewis acid Lewis base
ANS: E OBJ: Classify the role of a reactant given the chemical reaction. TOP: The Lewis Theory 90. In the following reaction, the SnCl4 functions as a(n) ____. SnCl4 + 2Cl SnCl62 a. b. c. d. e.
Brønsted-Lowry acid Brønsted-Lowry base Arrhenius base Lewis acid Lewis base
ANS: D OBJ: Classify the role of a reactant given the chemical reaction. TOP: The Lewis Theory 91. Which one of the following reactions can be classified as a Lewis acid-base reaction but not as a Brønsted-Lowry acid-base reaction? a. Al(OH)3(s) + OH(aq) Al(OH)4(aq) b. NH3(g) + H2O NH4+(aq) + OH(aq) c. CH3COO (aq) + H2O CH3COOH(aq) + OH(aq) d. H+(g) + H(g) H2(g) e. Ca(OH)2(s) + 2HCl(g) CaCl2(s) + 2H2O ANS: A OBJ: Identify the acid-base reaction that cannot be classified as a Lewis acid-base reaction. TOP: The Lewis Theory Whitten 10e
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92. Gaseous methylamine, CH3NH2, can be classified as ____. a. a Lewis base only b. Arrhenius and Brønsted-Lowry bases c. a Brønsted-Lowry base only d. Arrhenius and Lewis bases e. Brønsted-Lowry and Lewis bases ANS: E OBJ: Identify a compound as an Arrhenius, Lewis or Brønsted-Lowry base. TOP: The Lewis Theory 93. Which of the following statements is false? a. Arrhenius acids are also Brønsted-Lowry acids. b. Brønsted-Lowry acids are also Lewis acids. c. Brønsted-Lowry bases are also Arrhenius bases. d. Arrhenius bases are also Brønsted-Lowry bases. e. Brønsted-Lowry bases are also Lewis bases. ANS: C OBJ: Understand the relationship between Arrhenius, Brønsted-Lowry, and Lewis descriptions of acids and bases. TOP: The Lewis Theory 94. In this reaction CH3NH2 can be classified as ____. CH3NH2 + H2O CH3NH3+ methylamine water methylammonium ion a. b. c. d. e.
+ OH hydroxide ion
only an Arrhenius base only a Lewis base only a Brønsted-Lowry base a Brønsted-Lowry base and a Lewis base Arrhenius, Brønsted-Lowry, and Lewis bases
ANS: D OBJ: Classify the role of a reactant given the chemical reaction. TOP: The Lewis Theory 95. Based on the reactions we have studied, ammonia can be considered as ____. a. an Arrhenius base (only) b. a Lewis base (only) c. a Brønsted-Lowry base (only) d. both an Arrhenius base and a Lewis base e. both a Brønsted-Lowry base and a Lewis base ANS: E OBJ: Identify a compound as an Arrhenius, Lewis or Brønsted-Lowry base. TOP: The Lewis Theory 96. The most important use for Lewis theory occurs: a. when water is the solvent. b. when explaining the reactions between soluble strong acids and strong bases to form salts. c. when relating Arrhenius acids to Brønsted-Lowry acids. d. with transition metal complexes. e. none of these describes an important use for Lewis theory. Whitten 10e
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ANS: D OBJ: Identify an important application of Lewis theory. TOP: The Lewis Theory 97. In aqueous solution, which of the following would be an acid according to the definitions of the Arrhenius, the Brønsted-Lowry, and the Lewis theories? Stated differently, which of the following behaves as an acid when dissolved in water according to all three of these theories? a. HCl b. AlCl3 c. BF3 d. NaNH2 e. CN ANS: A OBJ: Identify the compound that would be considered an acid by Arrhenius, Brønsted-Lowry, and Lewis. TOP: The Lewis Theory 98. Which pair of reactants can be used in the preparation of hydrogen bromide, HBr, a volatile acid? a. H2SO4 and NaBr b. H3PO4 and NaBr c. HBrO4 and NaOH d. HBrO3 and NaOH e. NaBrO3 and H2O ANS: B OBJ: Identify the reactants used to prepare HBr. TOP: The Preparation of Acids 99. Write the balanced formula unit equation for the reaction of dinitrogen pentoxide, N2O5, with water to form an acid. What is the sum of the coefficients in the balanced equation? (Use the smallest whole numbers possible and don't forget coefficients of one.) a. 3 b. 4 c. 6 d. 8 e. 10 ANS: B OBJ: Write a balanced chemical equation given the reactants. | Sum the coefficients. TOP: The Preparation of Acids 100. Write the balanced formula unit equation for the reaction of tetraphosphorus decoxide, P4O10, with water to form an acid. What is the sum of the coefficients in the balanced equation? (Use the smallest whole numbers possible and don't forget coefficients of one.) a. 8 b. 9 c. 10 d. 11 e. 12 ANS: D DIF: Harder Question OBJ: Write a balanced chemical equation given the reactants. | Sum the coefficients. TOP: The Preparation of Acids Whitten 10e
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101. The reaction of PCl5 with water produces two acids, ____ and ____. a. H3PO3; HCl b. H3PO4; HCl c. H3PO3; HClO d. H3PO4; HClO e. H3PO3; HClO2 ANS: B OBJ: Identify the products given the reactants. TOP: The Preparation of Acids 102. The products of the reaction of PCl3 with water are ____ and ____. a. PCl5; HCl b. HPO2; HCl c. H3PO3; HCl d. PH3; HClO e. H3PO4; HCl ANS: C OBJ: Identify the products given the reactants. TOP: The Preparation of Acids 103. The products of the reaction of AsCl3 with water are ____ and ____. a. AsCl5; HCl b. H3AsO3; HCl c. AsH3; HClO d. AsH3; HClO4 e. H3AsO4; HCl ANS: B DIF: Harder Question OBJ: Identify the products given the reactants. TOP: The Preparation of Acids 104. Which of these common substances is basic? a. lemon juice b. oven cleaner c. digestive juice d. carbonated water (e.g. club soda) e. vinegar ANS: B OBJ: Identify the basic or acidic substance. TOP: Properties of Aqueous Solutions of Acids and Bases 105. Which of these common substances is neither acidic nor basic? a. bleach b. digestive juice c. Drano d. orange juice e. none of the above ANS: E OBJ: Identify the substance that is neither acidic nor basic. TOP: Properties of Aqueous Solutions of Acids and Bases Whitten 10e
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106. Which one of the following pairs of acids and conjugate bases is incorrectly labeled or incorrectly matched?
a. b. c. d. e.
Acid / Conjugate Base water / hydroxide acetic acid / carbonate hydrobromic acid / bromide nitric acid / nitrate sulfuric acid / hydrogen sulfate
ANS: B OBJ: Identify the incorrect conjugate acid-base pair. TOP: The Brønsted-Lowry Theory 107. Which of the following is a weak base? a. nitrate b. chloride c. perchlorate d. fluoride e. bromide ANS: D OBJ: Identify the weak base. TOP: Strengths of Acids 108. The net ionic equation for the reaction between aqueous ammonia and hydrochloric acid is a. HCl(aq) + NH3(aq) NH4Cl(aq). b. H+(aq) + OH–(aq) H2O(l). c. HCl(aq) + OH–(aq) Cl–(aq) + H2O(l). d. H+(aq) + NH3(aq) NH4+(aq). e. H+(aq) + Cl–(aq) + NH3(aq) NH4+(aq) + Cl–(aq). ANS: D DIF: moderate OBJ: Identify the net ionic reaction consistent with the given reactants. TOP: Acid-Base Reactions in Aqueous Solutions 109. What is the net ionic equation for the neutralization of hydrochloric acid with potassium
hydroxide? a. H+(aq) + OH–(aq) H2O(l) b. H+(aq) + Cl–(aq) + K+(aq) + OH–(aq) KCl(aq) + H2O(l) c. H+(aq) + Cl–(aq) + K+(aq) + OH–(aq) HCl(aq) + KOH(aq) d. HCl(aq) + K+(aq) + OH–(aq) KCl(aq) + H2O(l) e. HCl(aq) + KOH(aq) KCl(aq) + H2O(l) ANS: A DIF: moderate OBJ: Identify the net ionic reaction consistent with the given reactants. TOP: Acid-Base Reactions in Aqueous Solutions 110. Which of the following is a weak base in aqueous solution? a. HOCl b. CsOH c. NH3 d. HBr e. Ba(OH)2 Whitten 10e
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ANS: C DIF: easy OBJ: Identify the weak base. TOP: Acid-Base Reactions in Aqueous Solutions 111. Identify the conjugate base of the weakest acid. a. chlorite b. chlorate c. hyprochlorite d. perchlorate e. they are all equal ANS: C OBJ: Identify the strongest or weakest acid. TOP: Strengths of Acids 112. Identify the complex ion formed on reaction of Sn(OH)2 with excess strong base. a. SnO b. SnO3 and SnO4 c. [Sn(OH)6] d. [Sn(OH)3]or [Sn(OH)4]2 e. no reaction occurs ANS: D OBJ: Identify the complex ion product from reaction of a metal hydroxide with strong base. TOP: Amphoterism 113. Which of the following metal hydroxides is not amphoteric? a. Ca(OH)2 b. Co(OH)2 c. Be(OH)2 d. Al(OH)3 e. all are amphoteric ANS: A OBJ: Identify the metal hydroxide that is not amphoteric. TOP: Amphoterism 114. The formula for the conjugate base of HSO3- is: a. H2SO3 b. SO32c. HSO3-
d. OH-
e. H3O+
d. PO43-
e. H3O+
ANS: B OBJ: Identify the conjugate base of the polyatomic ion. TOP: Acidic Salts and Basic Salts 115. The formula for the conjugate acid of H2PO4- is: a. H3PO4 b. H2PO4c. HPO42ANS: A OBJ: Identify the conjugate acid of the polyatomic ion. TOP: Acidic Salts and Basic Salts
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116. In the following net ionic equation, identify the Brønsted-Lowry acid:
NO2-(aq) + HS-(aq) HNO2(aq) + S2-(aq) a. NO2b. HSc. HNO2
d. S2-
ANS: B OBJ: Identify the Brønsted-Lowery acid given the balanced equation. TOP: The Brønsted-Lowry Theory 117. Which of the following equations shows that isoquinoline, C9H7N, behaves as a Brønsted-
Lowry base in water? a. C9H7N(aq) + H2O(l) b. C9H7N(aq) + H2O(l) c. C9H7N(aq) + OH-(aq) d. C9H7N(aq) + H3O+(aq) e. C9H7NH+(aq) + H2O(l)
C9H7NH+(aq) + OH-(aq) C9H6N-(aq) + H3O+(aq) C9H6N-(aq) + H2O(l) C9H7NH+(aq) + H2O(l) C9H7N(aq) + H3O+(aq)
ANS: C OBJ: Identify the chemical equation consistent with the Brønsted-Lowry base designation. TOP: The Brønsted-Lowry Theory 118. The compound ammonia, NH3, is a weak base when dissolved in water. Which of the
following is the correct equation for the reaction of ammonia in water? a. NH3(aq) + H2O(l) NH4+(aq) + OH-(aq) b. NH3(aq) + H2O(l) NH2-(aq) + H3O+(aq) + c. NH3(aq) + H3O (aq) NH4+(aq) + H2O(l) d. NH3(aq) + OH-(aq) NH2-(aq) + H2O(l) e. NH3(aq) + H2O(l) NH2-(aq) + H3O+(aq) ANS: A OBJ: Identify the correct chemical equation for the ionization of a weak base. TOP: The Hydronium Ion (Hydrated Hydrogen Ion) 119. When ammonium perchlorate, NH4ClO4, is dissolved in water, will it give an acidic, basic, or
neutral solution? a. Acidic
b. Basic
c. Neutral
ANS: A OBJ: Identify if a solution of an ionic compound is acidic or basic. TOP: Acidic Salts and Basic Salts 120. When calcium acetate, Ca(CH3COO)2, is dissolved in water, will it give an acidic, basic, or
neutral solution? a. Acidic
b. Basic
c. Neutral
ANS: B OBJ: Identify if a solution of an ionic compound is acidic or basic. TOP: Acidic Salts and Basic Salts 121. When sodium bromide, NaBr, is dissolved in water, will it give an acidic, basic, or neutral
solution? a. Acidic
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ANS: C OBJ: Identify if a solution of an ionic compound is acidic or basic. TOP: Acidic Salts and Basic Salts 122. When potassium fluoride, KF, is dissolved in water, will it give an acidic, basic, or neutral
solution? a. Acidic
b. Basic
c. Neutral
ANS: B OBJ: Identify if a solution of an ionic compound is acidic or basic. TOP: Acidic Salts and Basic Salts 123. Which of the following is the correct definition for a Lewis base? a. provides OH- in water b. proton donor c. proton acceptor d. electron pair donor e. electron pair acceptor ANS: D OBJ: Identify the definition of Lewis base. TOP: The Lewis Theory 124. Which of the following is the correct definition for a Lewis acid? a. provides H+ in water b. proton donor c. proton acceptor d. electron pair donor e. electron pair acceptor ANS: E OBJ: Identify the definition of Lewis acid. TOP: The Lewis Theory 125. Which of the following is the correct definition for an Arrhenius acid? a. provides H+ in water b. provides OH- in water c. proton acceptor d. electron pair acceptor e. electron pair donor ANS: A OBJ: Identify the definition of Arrhenius acid. TOP: The Arrhenius Theory 126. Which of the following is the correct definition for an Arrhenius base? a. provides H+ in water b. provides OH- in water c. proton acceptor d. proton donor e. electron pair acceptor
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ANS: B OBJ: Identify the definition of Arrhenius base. TOP: The Arrhenius Theory CONCEPTUAL 1. Can water be classified as an Arrhenius acid and base? Can it be classified as a Brønsted-Lowry acid and base? Can it be classified as a Lewis acid and base? OBJ: Discuss the classification of water according to Arrhenius, Brønsted-Lowry, and Lewis. TOP: The Lewis Theory | The Brønsted-Lowry Theory | The Arrhenius Theory 2. Which is a stronger acid, H2O or H2S? Explain your answer. OBJ: Identify the stronger acid. TOP: Strengths of Acids | The Arrhenius Theory | The Brønsted-Lowry Theory | The Lewis Theory 3. Why does boiling vinegar help clear the kitchen of "fishy"odor after cooking fish? Hint: Fishy odors are caused by amines, which have the group NH2 bonded to them. OBJ: Classify a reaction given the reactants and explain the lack of odor of the products. TOP: Acid-Base Reactions MSC: Conceptual question 4. Acid rain is a result of industrial waste affecting the atmosphere. One of the major components is sulfuric acid. Describe the effects of acid rain hitting a limestone (calcium carbonate) structure and give an equation for this occurrence. OBJ: Write a balanced equation given the reactants and describe the fate of the basic reactant. TOP: Acid-Base Reactions 5. Why does it harm the pipes when acid is put down the drain, but the pipes are not harmed when Drano is put down the drain? OBJ: Describe the effect of acids and bases on metals. TOP: Acid-Base Reactions 6. Is there a difference between amphoteric and amphiprotic behavior? Give specific examples. OBJ: Compare and contrast amphoteric and amphiprotic. TOP: Amphoterism
Chapter 11—Reactions in Aqueous Solutions II: Calculations MULTIPLE CHOICE 1. What volume of 12.6 M HCl must be added to enough water to prepare 5.00 liters of 3.00 M HCl? a. 1.19 L b. 21.0 L c. 0.840 L d. 7.56 L e. 2.14 L ANS: A Whitten 10e
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OBJ: Calculate the molarity of a dilution given molarity of the concentrated stock and the final volume and molarity of the dilute solution. TOP: Calculations Involving Molarity 2. What volume of 12.0 M HNO3 is required to prepare 900. mL of 2.0 M HNO3 solution? a. 100. mL b. 150. mL c. 200. mL d. 250. mL e. 300. mL ANS: B OBJ: Calculate the molarity of a dilution given molarity of the concentrated stock and the final volume and molarity of the dilute solution. TOP: Calculations Involving Molarity 3. What mass of Ca(OH)2 is present in 500. mL of 0.00500 molar Ca(OH)2? a. 0.185 g b. 0.282 g c. 0.370 g d. 0.416 g e. 0.615 g ANS: A OBJ: Calculate grams solute given solution volume and molarity. TOP: Calculations Involving Molarity 4. How many grams of glucose, C6H12O6, are needed to make 5.00 L of 5.00 M solution? a. 0.139 g b. 4500. g c. 600. g d. 180 g e. 7.2 g ANS: B OBJ: Calculate grams solute given solution volume and molarity. TOP: Calculations Involving Molarity
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5. What is the molarity of 1600. mL of a solution that contains 3.25 g of H3PO4? a. 2.03 103 M b. 6.90 103 M c. 6.22 102 M d. 6.09 103 M e. 2.07 102 M ANS: E OBJ: Calculate solution molarity given solution volume and grams solute. TOP: Calculations Involving Molarity 6. What is the molarity of glucose solution if 437 g of glucose, C6H12O6, are dissolved in 2000 mL of solution? a. 0.206 M b. 0.824 M c. 1.21 M d. 1.21 103 M e. 2.42 M ANS: C OBJ: Calculate solution molarity given solution volume and grams solute. TOP: Calculations Involving Molarity 7. If 75.0 mL of 0.250 M HNO3 and 75.0 mL of 0.250 M KOH are mixed, what is the molarity of the salt in the resulting solution? a. 0.250 M b. 0.500 M c. 0.333 M d. 0.125 M e. 0.167 M ANS: D OBJ: Determine the molarity of the product made by mixing two known volumes of reactants of equal solute concentration. TOP: Calculations Involving Molarity 8. If 35 mL of 1.0 M H2SO4 is mixed with 35 mL of 2.0 M NaOH, how many moles of H2SO4 remain after completion of the reaction? a. 0.070 b. 0.035 c. 0.0175 d. 0.0525 e. zero ANS: E OBJ: Identify the moles of excess reactant given the volume and molarity of each reactant. TOP: Calculations Involving Molarity 9. What is the molarity of the NaBr produced when 50.0 mL of 4.80 M NaOH is mixed with 150.0 mL of 1.60 M HBr? a. 2.40 M b. 3.20 M c. 1.20 M d. 1.33 M e. 480 M Whitten 10e
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ANS: C OBJ: Determine the molarity of the product made by mixing two known volumes and molarities of reactants. TOP: Calculations Involving Molarity 10. What is the molarity of Sr(NO3)2 in a solution resulting from mixing 150.0 mL of 0.0200 M HNO3 with 150.0 mL of 0.0100 M Sr(OH)2? a. 0.00670 M b. 0.00330 M c. 0.00250 M d. 0.00500 M e. 0.0100 M ANS: D OBJ: Determine the molarity of the product made by mixing two known volumes and molarities of reactants. TOP: Calculations Involving Molarity 11. If 400. mL of 0.20 M HCl solution is added to 800. mL of 0.050 M Ba(OH)2 solution, the resulting solution will be ____ in BaCl2. a. 0.067 M b. 0.26 M c. 0.033 M d. 0.47 M e. 0.67 M ANS: C OBJ: Determine the molarity of the product made by mixing two known volumes and molarities of reactants. TOP: Calculations Involving Molarity 12. If 200. mL of 0.800 molar HClO4 is added to 400. mL of 0.200 molar Ba(OH)2 solution, the resulting solution will be ____ in Ba(ClO4)2. a. 0.100 M b. 0.0750 M c. 0.133 M d. 0.0670 M e. 0.0250 M ANS: C OBJ: Determine the molarity of the product made by mixing two known volumes and molarities of reactants. TOP: Calculations Involving Molarity 13. What is the molarity of the sodium sulfate in the solution resulting from the addition of 100. mL of 0.0500 M H2SO4 to 200. mL of 0.0500 M NaOH? a. 0.00833 M b. 0.0167 M c. 0.0333 M d. 0.0250 M e. 0.0500 M
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ANS: B OBJ: Determine the molarity of the product made by mixing two known volumes of reactants of equal solute concentration. TOP: Calculations Involving Molarity 14. How many mL of 0.250 M Ba(OH)2 are required to react with 42.0 mmol of HCl? a. 5.95 mL b. 84.0 mL c. 336 mL d. 168 mL e. 21.0 mL ANS: B OBJ: Determine the volume of base, given molarity, required to neutralize the given amount of acid. TOP: Calculations Involving Molarity 15. If 750 mL of 0.25 M HClO4 is added to 5000 mL of 0.50 M Ca(OH)2, which reactant remains and what is its molarity? a. Ca(OH)2; 2.5 M b. Ca(OH)2; 0.40 M c. HClO4; 0.42 M d. HClO4; 0.19 M e. Ca(OH)2; 0.42 M ANS: E OBJ: Identify the excess reactant and determine its molarity given the volume and molarity of each reactant. TOP: Calculations Involving Molarity 16. If 200. mL of 2.00 M H3PO4 solution is added to 600. mL of 2.00 M NaOH solution, the resulting solution will be ____ molar in Na3PO4. a. 0.500 b. 0.667 c. 0.800 d. 1.00 e. 0.100 ANS: A OBJ: Determine the molarity of the product made by mixing two known volumes and molarities of reactants. TOP: Calculations Involving Molarity 17. What is the molarity of the salt produced in the reaction of 100.0 mL of 0.0500 M HBr with 100.0 mL of 0.0600 M Ca(OH)2? a. 0.0250 M b. 0.0800 M c. 0.0400 M d. 0.0300 M e. 0.0125 M ANS: E OBJ: Determine the molarity of the product made by mixing two known volumes of reactants of equal solute concentration. TOP: Calculations Involving Molarity
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18. What is the formula and molarity of the salt produced by the reaction of 17 mL of 0.33 M H2SO4 and 44 mL of 0.23 M Sr(OH)2? a. SrSO4; 0.0920 M b. SrSO4; 0.16 M c. Sr(OH)2; 0.165 M d. SrSO4; 9.2 105 M e. SrH2; 0.0920 M ANS: A OBJ: Determine the identity and molarity of the product made by mixing two known volumes and molarities of reactants. TOP: Calculations Involving Molarity 19. If 50.0 mL of 0.0400 M HBr is added to 100.0 mL of 0.0300 M Ba(OH)2, what is the molarity of the acid or base that remains unreacted? a. 0.0150 M b. 0.0250M c. 0.0200 M d. 0.0133 M e. 0.00667 M ANS: D OBJ: Calculate the molarity of the excess reactant given the volume and molarity of each reactant. TOP: Calculations Involving Molarity 20. What volume of 0.122 M HCl would react with 26.2 mL of 0.176 M NaOH? a. 37.8 mL b. 18.2 mL c. 5.56 mL d. 26.3 mL e. 75.6 mL ANS: A OBJ: Determine the volume of acid, given molarity, required to neutralize the given volume and molarity of base. TOP: Calculations Involving Molarity 21. How many moles of HCl would react with 37.1 mL of 0.138 M Sr(OH)2? a. 0.00511 b. 0.0102 c. 10.2 d. 0.538 e. 0.00256 ANS: B OBJ: Determine the moles of acid required to neutralize the given volume and molarity of base. TOP: Calculations Involving Molarity 22. What volume of 0.0750 M Ba(OH)2 will completely react with 125 mL of 0.0350 M HCl? a. 29.2 mL b. 42.0 mL c. 230. mL d. 536 mL e. 53.6 mL
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ANS: A OBJ: Determine the volume of base, given molarity, required to neutralize the given volume and molarity of acid. TOP: Calculations Involving Molarity 23. What volume of 0.50 M KOH would be required to neutralize completely 500. mL of 0.25 M H3PO4 solution? a. 2.5 102 mL b. 1.4 103 mL c. 83 mL d. 7.5 102 mL e. 5.2 102 mL ANS: D OBJ: Determine the volume of base, given molarity, required to neutralize the given volume and molarity of acid. TOP: Calculations Involving Molarity 24. How many mL of 0.57 M AgNO3 will completely react with 121 mL of 0.95 M NaI? AgNO3 + NaI AgI + NaNO3 a. b. c. d. e.
72.6 mL 181 mL 202 mL 4.47 mL 0.202 mL
ANS: C OBJ: Determine the volume of a reactant, given molarity, required to consume a second reactant (volume and molarity given). TOP: Calculations Involving Molarity 25. Which of the following is not a property of an ideal primary standard? a. It must not react with or absorb components of the atmosphere. b. It must react according to one invariable reaction. c. It must have a high percentage purity. d. It must have a low formula weight. e. It should be nontoxic. ANS: D OBJ: Identify the properties of an ideal standard. TOP: Titrations 26. Assume you will titrate a sodium carbonate solution with sulfuric acid. All of the following apply except: a. An indicator will be used. b. The end point should coincide with the equivalence point. c. Either the mass of sodium carbonate or the molarity of the sulfuric acid must be known initially. d. The titration depends on the volume of water added to dissolve the sodium carbonate. e. The volume of sulfuric acid added will be carefully measured. ANS: D OBJ: Identify the information and data required to complete a titration. TOP: Titrations Whitten 10e
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27. During a titration the point at which stoichiometrically equivalent amounts of acid and base have reacted is called the ____ point. a. indicator b. equivalence c. end d. standardization e. primary standard ANS: B OBJ: Define a titration equivalence point. TOP: Titrations 28. During a titration the point at which the indicator changes color, suggesting the titration be stopped, is called the ____ point. a. indicator b. equivalence c. end d. standardization e. primary standard ANS: C OBJ: Define a titration end point. TOP: Titrations 29. A solution whose molarity is very accurately known is called: a. neutral b. acidic c. primary standard d. standard solution e. indicator ANS: D OBJ: Define standard solution. TOP: Titrations 30. What is the molarity of a potassium hydroxide solution if 38.65 mL of the KOH solution is required to titrate 25.84 mL of 0.1982 M hydrochloric acid solution? a. 0.1325 M b. 0.2963 M c. 0.8817 M d. 0.2648 M e. 0.01324 M ANS: A OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations 31. What is the molarity of a sulfurous acid solution if 23.7 mL of this H2SO3 solution requires 16.8 mL of 0.296 M NaOH for titration to the equivalence point? a. 0.210 M b. 0.358 M c. 0.105 M d. 0.421 M e. 0.0525 M
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ANS: C OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations 32. What is the molarity of a barium hydroxide solution if 18.62 mL of this Ba(OH)2 solution requires 35.84 mL of 0.2419 M HCl for titration to the equivalence point? a. 0.4656 M b. 0.2328 M c. 0.1164 M d. 0.3492 M e. 0.6984 M ANS: B OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations 33. What is the molarity of a phosphoric acid solution if 15.66 mL of this H3PO4 solution requires 43.81 mL of 0.2283 M NaOH for titration to the equivalence point? a. 1.925 M b. 0.1597 M c. 0.3193 M d. 0.2129 M e. 0.6387 M ANS: D OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations 34. If 20 mL of 0.010 M H3PO4 solution is completely neutralized by 60.0 mL of Ca(OH)2 solution, what is the molarity of the Ca(OH)2 solution? a. 0.010 M b. 0.200 M c. 0.030 M d. 0.040 M e. 0.0050 M ANS: E OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations 35. Calculate the molarity of an HClO4 solution if 40.0 mL of the HClO4 solution neutralizes 0.212 g of Na2CO3. a. 0.0250 M b. 0.0500 M c. 0.0750 M d. 0.100 M e. 0.0900 M ANS: D OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations
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36. Calculate the molarity of an HCl solution if 38.65 mL of this HCl solution is required to neutralize 0.2152 g of Na2CO3. a. 0.05251 M b. 0.02625 M c. 0.2104 M d. 0.05427 M e. 0.1050 M ANS: E OBJ: Calculate the molarity of a solution using titration data. TOP: Calculations for Acid-Base Titrations 37. Potassium hydrogen phthalate is often used to standardize solutions of strong bases. Highly pure samples of this solid weak acid are readily available. It is stable and easy to use in the laboratory. Calculate the molarity of a sodium hydroxide solution if 23.73 mL are required to titrate 0.5816 g of potassium hydrogen phthalate (C8H5O4K). C8H5O4K + NaOH C8H4O4KNa + H2O a. b. c. d. e.
0.1042 M 0.2208 M 0.3116 M 0.1200 M 0.06825 M
ANS: D OBJ: Calculate the molarity of a base standardized using KHP. TOP: Calculations for Acid-Base Titrations 38. Calculate the molarity of a NaOH solution if 35.42 mL of this NaOH solution is required to titrate 0.7566 g of KHP, KC6H4(COO)(COOH). a. 0.05278 M b. 0.1046 M c. 0.2092 M d. 0.3128 M e. 0.0105 M ANS: B OBJ: Calculate the molarity of a base standardized using KHP. TOP: Calculations for Acid-Base Titrations 39. A sample of impure iron ore reacts with exactly 28.3 mL of 0.100 M HCl. How many grams of iron were contained in the sample? FeS (s) + 2HCl (aq) H2S (g) + FeCl2 (aq) a. b. c. d. e.
0.158 g 0.316 g 79.0 g 0.0014 g 0.079 g
ANS: E OBJ: Calculate the mass of metal in an ore using titration data. TOP: Calculations for Acid-Base Titrations
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40. A 0.5240-g sample of impure solid Na2CO3 is neutralized by 43.60 mL of 0.1077 M H2SO4. What mass of Na2CO3 was contained in the sample? There are no acidic or basic impurities present in the sample. a. 0.4977 g b. 0.5210 g c. 0.5106 g d. 0.5048 g e. 0.4624 g ANS: A OBJ: Calculate the mass of sodium carbonate in an impure sample using titration data. TOP: Calculations for Acid-Base Titrations 41. A 0.7860-g sample of impure solid Na2CO3 is neutralized by 23.48 mL of 0.1082 M HCl. What percentage purity of Na2CO3 was contained in the sample? There are no acidic or basic impurities present in the sample. a. 34.24% b. 12.16% c. 17.13% d. 32.32% e. 68.52% ANS: C OBJ: Calculate the percent of an analyte in an impure sample using titration data. TOP: Calculations for Acid-Base Titrations 42. An impure sample of (COOH)2 which weighed 1.432 g was dissolved in water and titrated with standard KOH solution. The titration required 41.66 mL of 0.2008 M KOH solution. Calculate the % (COOH)2 in the sample. There are no acidic or basic impurities present in the sample. a. 12.62% b. 26.30% c. 30.65% d. 15.32% e. 21.25% ANS: B OBJ: Calculate the percent of an analyte in an impure sample using titration data. TOP: Calculations for Acid-Base Titrations 43. When balancing oxidation-reduction reactions, all of the following apply except: a. There must be mass balance. b. Half-reactions are balanced first, and then added. c. There must be charge balance. d. The electrons must always cancel in the balanced reaction. e. The balanced reaction will always have a zero charge on both sides of the equation. ANS: E OBJ: Understand what is required to balance a redox reaction. TOP: Balancing Redox Reactions
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44. What is the oxidation number of arsenic in K3AsO4? a. +1 b. +2 c. +3 d. +4 e. +5 ANS: E OBJ: Determine that oxidation number of an atom in a compound. TOP: Balancing Redox Reactions 45. What is the oxidation number of arsenic in H2AsO42? a. +1 b. +2 c. +3 d. +4 e. +5 ANS: D OBJ: Determine that oxidation number of an atom in a compound. TOP: Balancing Redox Reactions 46. What is the oxidation number of phosphorus in Ca3(PO4)2? a. +6 b. +7 c. +3 d. +4 e. +5 ANS: E OBJ: Determine that oxidation number of an atom in a compound. TOP: Balancing Redox Reactions 47. What is the oxidation number of S in Na2SO312H2O? a. +6 b. +2 c. +3 d. +4 e. +5 ANS: D OBJ: Determine that oxidation number of an atom in a compound. TOP: Balancing Redox Reactions 48. In which of the following is the oxidation number of the underlined element given incorrectly?
a. b. c. d. e.
Element / Oxidation number K2Cr2O7 / +6 NaAl(OH)4 / +3 HIO4 / +5 (NH4)2SO4 / +6 NaHSO3 / +4
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ANS: C OBJ: Identify the compound with an incorrect oxidation number. TOP: Balancing Redox Reactions 49. Which of the following is not a common oxidizing agent? a. KMnO4 b. LiCl c. HNO3 d. K2Cr2O7 e. H2O2 ANS: B OBJ: Identify the species that is not an oxidizing agent. TOP: Balancing Redox Reactions 50. What is the coefficient of NaCl in the balanced formula unit equation? NaClO3 + H2O + I2 HIO3 + NaCl a. b. c. d. e.
1 2 3 4 5
ANS: E OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 51. Balance the following equation. How many HCl are there on the left side of the balanced equation? K2Cr2O7 + Na2SO3 + HCl KCl + Na2SO4 + CrCl3 + H2O a. b. c. d. e.
1 2 3 4 8
ANS: E OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 52. Balance the following equation for a reaction that occurs in basic medium in a nickel-cadmium alkaline battery. What is the coefficient of H2O in the balanced equation? H2O + Cd + Ni2O3 Cd(OH)2 + Ni(OH)2 a. b. c. d. e.
1 2 3 4 none of these
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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53. Balance this equation for a reaction in basic solution. What is the coefficient of H2O? KOH + Cl2 KClO3 + KCl + H2O a. b. c. d. e.
8 2 3 4 6
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 54. Balance the following formula unit equation. What is the sum of all of the coefficients? (Do not forget coefficients of one.) H2SO4 + HI I2 + SO2 + H2O a. b. c. d. e.
7 9 11 13 5
ANS: A OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 55. Balance the following formula unit equation. What is the sum of all of the coefficients? (Do not forget coefficients of one.) KMnO4 + H2O2 + H2SO4 O2 + MnSO4 + K2SO4 + H2O a. b. c. d. e.
22 24 26 28 30
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 56. Balance the following formula unit equation. What is the sum of all of the coefficients? (Do not forget coefficients of one.) HNO3 + ZnS S + NO + Zn(NO3)2 + H2O a. b. c. d. e.
23 25 27 29 31
ANS: A OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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57. Balance the following formula unit equation for a reaction in basic solution. What is the sum of all of the coefficients? (Do not forget coefficients of one.) KMnO4 + H2O + Cu Cu(OH)2 + MnO2 + KOH a. b. c. d. e.
8 12 14 16 22
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 58. Balance the following equation. How many H+ are there in the balanced equation? (COOH)2 + MnO4 + H+ CO2 + Mn2+ + H2O a. b. c. d. e.
6 2 3 4 8
ANS: A OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 59. Balance the following net ionic equation. What is the coefficient of H2O? MnO4 + H+ + Br Mn2+ + Br2 + H2O a. b. c. d. e.
8 9 3 4 6
ANS: A OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 60. Based on the following equation (when balanced in acidic solution), the Br ions lose how many electrons? MnO4 + H+ + Br Mn2+ + Br2 + H2O a. b. c. d. e.
5 8 10 2 16
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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61. Balance the following net ionic equation. What is the coefficient of S? H2S + NO3 + H+ S + NO + H2O a. b. c. d. e.
1 2 3 4 none of these
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 62. Balancing the following net ionic equation, how many H+ are there? Sb + H+ + NO3 Sb4O6 + NO + H2O a. b. c. d. e.
1 6 3 4 5
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 63. How many H2O are there in the balanced equation? NiS + NO3 + H+ Ni2+ + S + NO + H2O a. b. c. d. e.
one two three four five
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 64. Balance the following net ionic equation. What is the coefficient of OH? Cl2 + OH Cl + ClO3 + H2O a. b. c. d. e.
1 2 4 5 6
ANS: E OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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65. Balance the following net ionic equation. What is the sum of the coefficients? (Do not forget coefficients of one.) H2S + H+ + Cr2O72 Cr3+ + S + H2O a. b. c. d. e.
18 20 22 24 26
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 66. Balance the following equation. What is the sum of all coefficients? (Do not forget coefficients of one.) Cu + H+ + SO42 Cu2+ + H2O + SO2 a. b. c. d. e.
9 10 11 12 13
ANS: B OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 67. Balance the following net ionic equation. What is the sum of the coefficients? (Do not forget coefficients of one.) MnO4 + I + H2O I2 + MnO2 + OH a. b. c. d. e.
21 23 25 27 29
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 68. Balance the following net ionic equation. Use H+ rather than H3O+. What is the coefficient of NO3? Cr2O72 + HNO2 Cr3+ + NO3 (acidic solution) a. b. c. d. e.
1 2 3 4 5
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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69. Balance the following net ionic equation. Use H+ rather than H3O+. What is the coefficient of H2O? C + H+ + SO42 CO2 + SO2 (acidic solution) a. b. c. d. e.
1 2 3 4 5
ANS: B OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 70. In the following net ionic reaction, ____ is the oxidizing agent and ____ is oxidized. C + H+ + SO42 CO2 + SO2 (acidic solution) a. b. c. d. e.
H+; CO2 C; CO2 SO42; H+ SO42; C C; SO42
ANS: D OBJ: Identify the species in the balanced equation that is oxidized and the oxidizing agent. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 71. Balance the following net ionic equation. Use H+ rather than H3O+. What is the coefficient of H2S? H2S + MnO4 SO42 + Mn2+ (acidic solution) a. b. c. d. e.
1 2 3 4 5
ANS: E OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 72. Balance the following net ionic equation. What is the coefficient of OH? MnO4 + NH3 NO3 + MnO2 (basic solution) a. b. c. d. e.
2 3 5 7 9
ANS: C OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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73. Balance the following net ionic equation. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) Zn + NO3 Zn2+ + N2 (acidic solution) a. b. c. d. e.
25 27 29 31 33
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 74. Balance the following net ionic equation. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) H2O2 + Fe2+ Fe3+ (in acidic solution) a. b. c. d. e.
13 15 7 9 11
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 75. Consider the following net ionic equation. Which species is oxidized? MnO4 + SO32 Mn2+ + SO42 (acidic solution) a. b. c. d. e.
MnO4 Mn2+ SO32 SO42 no species is oxidized
ANS: C OBJ: Identify the species oxidized in the given reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 76. Balance the following net ionic equation. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) I + NO2 NO + I2 (acidic solution) a. b. c. d. e.
11 13 15 17 19
ANS: B OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen Whitten 10e
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77. Balance the following net ionic equation. Use H+ rather than H3O+. What is the sum of the coefficients? (Do not forget coefficients of one.) MnO4 + Fe2+ Mn2+ + Fe3+ (acid solution) a. b. c. d. e.
24 26 28 30 32
ANS: A OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 78. Balance the following net ionic equation. What is the sum of the coefficients? (Do not forget coefficients of one.) PbO2 + SeO32 PbO + SeO42 (in basic solution) a. b. c. d. e.
eight ten twelve four six
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 79. Balance the following net ionic equation. What is the sum of the coefficients? (Do not forget coefficients of one.) H2CO + AlH4 CH3OH + Al3+ (in basic solution) a. b. c. d. e.
26 16 22 18 13
ANS: D OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 80. Balance the following net ionic equation. What is the coefficient of H2O? MnO4 + Bi MnO2 + Bi(OH)3 (basic solution) a. b. c. d. e.
1 2 3 4 5
ANS: B OBJ: Balance the given redox reaction. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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81. In acidic solution MnO4 oxidizes H3AsO3, a weak acid, to H3AsO4, a weak acid, and is reduced to Mn2+. Write the balanced net ionic equation for this reaction. How many H+ are there in the balanced equation? a. 1 b. 2 c. 3 d. 4 e. 6 ANS: E OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 82. Write the balanced net ionic half-reaction for the reduction of MnO4 to Mn2+ in acidic solution. What is the sum of the coefficients (including the electrons)? (Do not forget coefficients of one.) a. 22 b. 19 c. 8 d. 14 e. 15 ANS: B OBJ: Determine the balanced half-reaction given the reactant and product. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 83. Write the balanced net ionic half-reaction for the oxidation of H2O to O2 in acidic solution. What is the sum of the coefficients (including the electrons)? (Do not forget coefficients of one.) a. 11 b. 5 c. 9 d. 7 e. 15 ANS: A OBJ: Determine the balanced half-reaction given the reactant and product. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 84. Write the balanced net ionic equation for the reaction of hydrogen sulfide with bromate ions, BrO3, in acidic solution to form sulfur and bromide ions. How many H+ are there in the balanced equation? a. 1 b. 2 c. 3 d. 6 e. zero ANS: E OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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85. In basic solution CrO42 oxidizes HSnO2 to HSnO3 and is reduced to CrO2. Write the balanced net ionic equation for this reaction. How many OH are there in the balanced equation? a. 1 b. 2 c. 3 d. 4 e. 5 ANS: B OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 86. In basic solution MnO4 oxidizes NO2 to NO3 and is reduced to MnO2. How many H2O are there in the balanced net ionic equation? a. 1 b. 2 c. 3 d. 4 e. 5 ANS: A OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 87. Iron(II) ions reduce dichromate ions in acidic solution to chromium(III) ions and form ferric ions. Write the balanced net ionic equation. Use H+ rather than H3O+. What is the sum of all the coefficients? (Do not forget coefficients of one.) a. 24 b. 26 c. 28 d. 32 e. 36 ANS: E OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 88. Chlorous acid, HClO2, oxidizes sulfur dioxide, SO2, to sulfate ions, SO42, and is reduced to chloride ions, Cl, in acidic solution. Use H+ rather than H3O+. Write the balanced net ionic equation for the reaction. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 11 b. 13 c. 15 d. 17 e. 19 ANS: B OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen
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89. In basic solution CrO42 oxidizes HSnO2 to HSnO3 and is reduced to CrO2. Write the balanced net ionic equation for this reaction. What is the sum of the coefficients? (Do not forget coefficients of one.) a. 9 b. 15 c. 13 d. 6 e. 10 ANS: C OBJ: Determine the balanced net ionic redox reaction given the reactants and products. TOP: Adding H+, OH–, or H2O to Balance Oxygen or Hydrogen 90. What volume of 0.0100 M KMnO4 solution is required to oxidize 42.5 mL of 0.0100 M FeSO4 sulfuric acid solution? MnO4 + 8H+ + 5Fe2+ Mn2+ + 5Fe3+ + 4H2O a. b. c. d. e.
16.0 mL 8.5 mL 21.3 mL 80.0 mL 31.9 mL
ANS: B OBJ: Calculate the volume of reactant consumed using the balanced reaction and redox titration data. TOP: Calculations for Redox Reactions 91. What volume of 0.100 M (COOH)2 solution would be required to react with 0.164 grams of KMnO4? 5(COOH)2 + 2MnO4 + 6H+ 10CO2 + 2Mn2+ + 8H2O a. b. c. d. e.
25.9 mL 51.8 mL 77.8 mL 104 mL 90.8 mL
ANS: A OBJ: Calculate the volume of reactant consumed using the balanced reaction and redox titration data. TOP: Calculations for Redox Reactions 92. What is the molarity of a solution of FeSO4 if 25.06 mL of it reacts with 38.19 mL of 0.1214 M KMnO4? MnO4 + 8H+ + 5Fe2+ Mn2+ + 5Fe3+ + 4H2O a. b. c. d. e.
0.1854 M 0.3992 M 0.07985 M 0.4267 M 0.9250 M
ANS: E OBJ: Calculate the molarity of reactant consumed using the balanced reaction and redox titration data. TOP: Calculations for Redox Reactions
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93. What mass of molybdenum(III) oxide, Mo2O3, will be completely oxidized to potassium molybdate, K2MoO4, by 35.0 mL of 0.200 M KMnO4? 3MnO4 + 5Mo3+ + 8H2O 3Mn2+ + 5MoO42 + 16 H+ a. b. c. d. e.
8.40 g 4.20 g 1.40 g 2.80 g 6.40 g
ANS: C OBJ: Calculate the mass of reactant consumed using the balanced reaction and redox titration data. TOP: Calculations for Redox Reactions 94. What volume of 0.1066 M Na2S2O3 solution would be required to react with 24.32 mL of 0.1008 M I2 solution? Na2S2O3 + I2 Na2S4O6 + NaI (unbalanced) a. b. c. d. e.
45.99 mL 5.75 mL 11.50 mL 23.00 mL 34.50 mL
ANS: A OBJ: Calculate the volume of reactant consumed given the unbalanced reaction and redox titration data. TOP: Calculations for Redox Reactions 95. What volume of 0.1084 M (COOH)2 solution would be required to react with 0.1268 grams of KMnO4? (COOH)2 + MnO4 + H+ CO2 + Mn2+ + H2O (unbalanced) a. b. c. d. e.
18.50 mL 37.02 mL 55.51 mL 24.02 mL 66.61 mL
ANS: A OBJ: Calculate the volume of reactant consumed given the unbalanced reaction and redox titration data. TOP: Calculations for Redox Reactions 96. What is the molarity of a K2Cr2O7 solution if 20.0 mL of the solution requires 60.4 mL of 0.200 M KI solution for complete reaction? K2Cr2O7 + KI + H+ Cr3+ + I2 + H2O (unbalanced) a. b. c. d. e.
1.55 M 3.63 M 0.101 M 0.603 M 0.280 M
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ANS: C OBJ: Calculate the molarity of reactant consumed given the unbalanced reaction and redox titration data. TOP: Calculations for Redox Reactions 97. A 30.0 mL sample of a solution of NaClO3 that contains 1.06 g of NaClO3 is to react with a solution of I2. What is the molarity of the NaClO3 solution? NaClO3 + H2O + I2 HIO3 + NaCl (unbalanced) a. b. c. d. e.
5.53 102 M 0.332 M 2.00 M 0.249 M 2.67 102 M
ANS: B OBJ: Calculate the molarity of reactant consumed given the unbalanced reaction and redox titration data. TOP: Calculations for Redox Reactions 98. A 25.0-mL sample of 0.0833 M NaClO3 reacted with 30.0 mL of an aqueous solution of I2. How many grams of I2 were contained in the I2 solution? NaClO3 + H2O + I2 HIO3 + NaCl (unbalanced) a. b. c. d. e.
0.264 g 0.397 g 0.236 g 0.159 g 0.317 g
ANS: E OBJ: Calculate the mass of reactant consumed given the unbalanced reaction and redox titration data. TOP: Calculations for Redox Reactions 99. When household ammonia is mixed with bleach, NaOCl, toxic chlorine gas and hydrazine, N2H4 is produced. What volume of 0.75 M NH3 would react with 100 mL of 0.35 M NaOCl? NH3 + OCl Cl2 + N2H4 (unbalanced) a. b. c. d. e.
23.5 Ml 100 mL 94 mL 26 mL 47 mL
ANS: E OBJ: Calculate the volume of reactant consumed given the unbalanced reaction and redox titration data. TOP: Calculations for Redox Reactions
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100. What volume of 0.1125 M K2Cr2O7 would be required to oxidize 48.16 mL of 0.1006 M Na2SO3 in acidic solution? The products include Cr3+ and SO42 ions. a. 14.36 mL b. 28.75 mL c. 43.12 mL d. 56.12 mL e. 32.15 mL ANS: A DIF: Harder Question OBJ: Calculate the volume of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions 101. In basic solution MnO4 oxidizes NO2 to NO3 and is reduced to MnO2. Calculate the volume of 0.1152 M KMnO4 solution that would be required to oxidize 30.48 mL of 0.1024 M NaNO2. a. 9.03 mL b. 18.06 mL c. 27.09 mL d. 45.16 mL e. 29.42 mL ANS: B DIF: Harder Question OBJ: Calculate the volume of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions 102. In basic solution MnO4 oxidizes NO2 to NO3 and is reduced to MnO2. Calculate the volume of 0.1025 M KMnO4 solution that would be required to oxidize 30.55 mL of 0.1075 M NaNO2. a. 10.68 mL b. 21.36 mL c. 32.04 mL d. 16.06 mL e. 42.75 mL ANS: B DIF: Harder Question OBJ: Calculate the volume of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions 103. In acidic solution IO3 oxidizes Ti3+ to Ti4+ and is reduced to I. How many mL of 0.0200 M KIO3 would be required to oxidize 0.932 moles of Ti2(SO4)3 in acidic solution? a. 7.50 mL b. 15.5 mL c. 21.5 mL d. 87.5 mL e. 75.0 mL ANS: B DIF: Harder Question OBJ: Calculate the volume of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions Whitten 10e
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104. What is the molarity of a K2Cr2O7 solution if 35.0 mL of it are required for complete reaction with 25.0 mL of 0.161 M Fe(NH4)2(SO4)2 solution? The products of the reaction include Fe3+ and Cr3+. a. 0.0192 M b. 0.0383 M c. 0.155 M d. 0.345 M e. 0.690 M ANS: A DIF: Harder Question OBJ: Calculate the molarity of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions 105. What is the molarity of a Na2Cr2O7 solution if 22.5 mL of it is required to oxidize 33.0 mL of 0.150 M Fe(NH4)2(SO4)? The reaction products include Cr3+ and Fe3+. a. 0.184 M b. 0.220 M c. 0.0367 M d. 0.0440 M e. 0.0660 M ANS: C DIF: Harder Question OBJ: Calculate the molarity of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions 106. A 50.0-mL sample of K2Cr2O7 solution oxidizes 1.500 g of Na2SO3 to Na2SO4. Cr2(SO4)3 is also produced. What is the molarity of the K2Cr2O7 solution? a. 0.0794 M b. 0.476 M c. 2.96 M d. 0.0952 M e. 0.0158 M ANS: A DIF: Harder Question OBJ: Calculate the molarity of reactant consumed given the reactants, products, and redox titration data. TOP: Calculations for Redox Reactions
Dynamic Questions 107. In the following reaction, which species is oxidized?
3Ag2S(s) + 8H+(aq) + 2NO3–(aq) 6Ag+(aq) + 3S(s) + 2NO(g) + 4H2O a. b. c. d. e.
NO3– Ag2S Ag+ NO H+
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ANS: B DIF: moderate OBJ: Determine the species that is oxidized given the balanced reaction. TOP: Redox Reactions 108. What mass of Na2CO3 is present in 0.300 L of a 0.629 M Na2CO3 solution? a. 20 g b. 31.8 g c. 66.7 g d. 50.6 g e. 222 g ANS: A DIF: easy OBJ: Calculate the mass of solute given volume and molarity. TOP: Calculations Involving Molarity 109. How many moles of sulfate ions are there in a 0.545-L solution of 0.489 M Al2(SO4)3? a. 0.267 mol b. 0.800 mol c. 3.34 mol d. 0.0888 mol e. 2.69 mol ANS: B DIF: moderate OBJ: Calculate the moles of ions given the volume and molarity of an ionic compound. TOP: Calculations Involving Molarity 110. The reaction of HCl with NaOH is represented by the equation
HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) What volume of 0.135 M HCl is required to titrate 39.8 mL of 0.718 M NaOH? a. 3.86 mL b. 7.41 mL c. 212 mL d. 39.8 mL e. 7.48 mL ANS: C DIF: moderate OBJ: Calculate the volume of acid required to neutralize the given amount of base. TOP: Calculations for Acid-Base Titrations 111. In a volumetric analysis experiment, an acidic aqueous solution of methanol (CH3OH) is
titrated with a solution of potassium dichromate (K2Cr2O7) according to the following balanced chemical equation: 2K2Cr2O7(aq) + 8H2SO4(aq) + 3CH3OH(aq) 2Cr2(SO4)3(aq) + 11H2O(l) + 3HCOOH(aq) + 2K2SO4(aq) What volume of 0.00389 M K2Cr2O7 is required to titrate 1.77 g of CH3OH dissolved in 20.0 mL of solution? Whitten 10e
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a. b. c. d. e.
21.3 mL 683 mL 9.47 mL 20.0 mL 303 mL
ANS: C DIF: moderate OBJ: Calculate the volume of reactant required to oxidize a given mass of reactant. TOP: Calculations for Redox Reactions 112. An impure sample of benzoic acid (C6H5COOH, 122.12 g/mol) is titrated with 0.3928 M
NaOH. A 1.355053-g sample requires 18.13 mL of titrant to reach the endpoint. What is the percent by mass of benzoic acid in the sample? C6H5COOH(aq) + NaOH(aq) NaC6H5COO(aq) + H2O(l) a. b. c. d. e.
0.005832 % 0.7121 % 100.0 % 5.832 % 64.18 %
ANS: E DIF: difficult OBJ: Calculate the percent mass of reactant in a sample given the titration data. TOP: Calculations for Acid-Base Titrations 113. In a volumetric analysis experiment, a solution of sodium oxalate (Na2C2O4) in acidic solution
is titrated with a solution of potassium permanganate (KMnO4) according to the following balanced chemical equation: 2KMnO4(aq) + 8H2SO4(aq) + 5Na2C2O4(aq) 2MnSO4(aq) + 8H2O(l) + 10CO2(g) + 5Na2SO4(aq) + K2SO4(aq) It required 20.0 mL of 0.0337 M KMnO4 to reach the endpoint. What mass of Na2C2O4 was present initially? a. 1.81 g b. 0.0361 g c. 11.3 g d. 0.0903 g e. 0.226 g ANS: E DIF: moderate OBJ: Calculate the mass of a reactant given the redox titration data. TOP: Calculations for Redox Reactions
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114. A 50.00-mL sample of a weak acid is titrated with 0.0955 M NaOH. At the endpoint, it is
found that 32.56 mL of titrant was used. What was the concentration of the weak acid? a. 0.0622 M b. 3.11 M c. 0.0955 M d. 5.87 10–5 M e. 0.147 M ANS: A DIF: moderate OBJ: Calculate the concentration of acid from titration data. TOP: Calculations for Acid-Base Titrations 115. When the following oxidation–reduction reaction in acidic solution is balanced, what is the
lowest whole-number coefficient for H+, and on which side of the balanced equation should it appear? MnO4–(aq) + F–(aq) Mn2+(aq) + F2(g) a. b. c. d. e.
1, reactant side 2, product side 8, reactant side 16, reactant side 4, product side
ANS: D DIF: moderate OBJ: Balance the acidic redox reaction. TOP: Balancing Redox Reactions 116. Balance the following half-reaction occurring in acidic solution.
NO3–(aq) HNO2(aq) a. b. c. d. e.
NO3–(aq) + 3H(aq) + 2e HNO2(aq) + H2O(l) NO3–(aq) + H2O(l) + 2e HNO2(aq) + 3H(aq) NO3–(aq) + 3H(aq) HNO2(aq) + H2O(l) + 2e NO3–(aq) + 2e HNO2(aq) + 3H(aq) + H2O(l) NO3–(aq) + 3H(aq) HNO2(aq) + H2O(l)
ANS: A DIF: difficult OBJ: Balance the acidic half reaction. TOP: Balancing Redox Reactions 117. The concentration of SO32- in a solution is determined by titrating it with a 0.1146M
dichromate solution. The balanced net ionic equation for the reaction is: Cr2O72- + 3SO32- + 8H3O+ 2Cr3+ + 3SO42- + 12H2O In one experiment, 23.84mL of the 0.1146M dichromate solution is required to react completely with 40.00mL of the SO32- solution. Calculate the concentration of the SO32solution. a. 0.02277M b. 0.06830M c. 0.1923M d. 0.2049M e. 0.5768M Whitten 10e
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ANS: D OBJ: Calculate the molarity of a solution using titration data. TOP: Titrations 118. What volume of 0.378M hydroiodic acid (HI) is required to neutralize 21.6mL of 0.520M
barium hydroxide, Ba(OH)2? a. 5.83mL b. 15.7mL
c. 29.7mL
d. 59.4mL
e. 80.0mL
ANS: D OBJ: Calculate the volume of acid required to neutralize a base. TOP: Calculations for Acid-Base Titrations 119. KHP (Molar Mass = 204.22g/mol) is a solid, monoprotic acid frequently used in the
laboratory to standardize strong base solutions. How many grams of KHP are needed to neutralize 37.9mL of a 0.124M KOH solution? a. 0.160g b. 0.324g c. 0.668g d. 0.739g e. 0.960g ANS: E OBJ: Calculate the mass of KHP required to neutralize a base. TOP: Calculations for Acid-Base Titrations CONCEPTUAL 1. Describe some features of an ideal primary standard. OBJ: Define primary standard as applied to titrations. TOP: Titrations | Primary Standards 2. You obtain a sample of impure calcium carbonate. Describe the steps involved to determine the percentage of calcium carbonate in the sample. OBJ: Describe the titration analysis of an impure sample. TOP: Titrations 3. Describe several common everyday processes that involve redox reactions. OBJ: Identify some common redox reactions. TOP: Redox Reactions 4. Compare an acid-base titration to a redox titration. In what ways are these titrations similar? Different? OBJ: Compare and contrast redox and acid-base titrations. TOP: Titrations 5. Consider an indicator changing colors during a titration. How is this possible? OBJ: Describe the chemistry which causes the change in color of an indicator. TOP: Indicators
Chapter 12—Gases and the Kinetic-Molecular Theory MULTIPLE CHOICE Whitten 10e
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1. Which of the following statements is false? a. Condensed states have much higher densities than gases. b. Molecules are very far apart in gases and closer together in liquids and solids. c. Gases completely fill any container they occupy and are easily compressed. d. Vapor refers to a gas formed by evaporation of a liquid or sublimation of a solid. e. Solid water (ice), unlike most substances, is denser than its liquid form (water). ANS: E OBJ: Understand the difference between solids, liquids, and gases. TOP: Comparison of Solids, Liquids, and Gases 2. Which physical state / property is incorrectly matched? a. liquids and solids / rigid shape b. gases / easily compressed c. gases and liquids / flow d. solids / higher density than gases e. liquids / incompressible ANS: A OBJ: Identify the incorrect physical state-property pair. TOP: Comparison of Solids, Liquids, and Gases 3. Which of the following substances would have the greatest molar volume? a. H2O(s) b. H2O c. H2O(g) d. CCl4(s) e. CCl4 ANS: C OBJ: Identify the physical state with the greatest molar volume. TOP: Comparison of Solids, Liquids, and Gases 4. Which of the following statements is false? a. The earth's atmosphere is a mixture of gases and particles of liquids and solids b. The three major gaseous components are N2, O2, and Ar. c. Atmospheric moisture varies. d. All gases mix completely unless they react with each other. e. The concentration of the fourth largest component of the atmosphere, CO2, is the same for all locations on the planet, but is increasing. ANS: E OBJ: Know the composition of the atmosphere and properties of gases. TOP: Composition of the Atmosphere and Some Common Properties of Gases
Whitten 10e
Test Bank
392
5. Which statement is false? a. The density of a gas is constant as long as its temperature remains constant. b. Gas expands without limit. c. Gases diffuse into each other and mix almost immediately when put into the same container. d. The molecular mass of a gaseous compound is an invariable quantity. e. Pressure must be exerted on a sample of a gas in order to confine it. ANS: A OBJ: Know the properties and behavior of gases. TOP: Composition of the Atmosphere and Some Common Properties of Gases 6. Which variable is not used to describe the amounts and properties of gases? a. temperature b. pressure c. compressibility d. volume e. number of molecules present ANS: C OBJ: Identify the variable not included in the ideal gas law. TOP: Composition of the Atmosphere and Some Common Properties of Gases 7. What is the atmospheric pressure in kPa if a mercury barometer reads 748 torr? a. 0.984 kPa b. 99.7 kPa c. 14.5 kPa d. 103 kPa e. 75500 kPa ANS: B OBJ: Convert between pressure units. TOP: Pressure 8. Hurricane Katrina recorded a low pressure reading of 902 mbar. How many atm was that? a. 0.890 atm b. 0.913 atm c. 1.18 atm d. 0.847 atm e. 0.839 atm ANS: A OBJ: Convert between pressure units. TOP: Pressure 9. Which of the following statements concerning pressure is false? a. The pressure units torr and mm Hg are equivalent. b. Atmospheric pressure increases at higher elevation. c. The SI pressure unit the atmosphere is equal to 14.7 lb/in2. d. Typical atmospheric pressure at sea level is 760 mm Hg. e. Barometers are used to measure changes in atmospheric pressure. ANS: B OBJ: Know the units, measurement, and trends in atmospheric pressure. TOP: Pressure Whitten 10e
Test Bank
393
10. Which statement is false? a. Atmospheric pressure varies with atmospheric conditions and distance above sea level. b. Pilots use portable barometers to determine their altitudes. c. A tire gauge measures the absolute pressure in the tire. d. At sea level, at a latitude of 45 and at 0C, the average atmospheric pressure supports a 760 mm high column of mercury in a simple barometer; this average sea-level pressure of 760 mm Hg is also called one atmosphere of pressure. e. The SI unit of pressure is the pascal (Pa), defined as the pressure exerted by a force of one newton acting on an area of one square meter. ANS: C DIF: Harder Question OBJ: Know the units, measurement, and trends in atmospheric pressure. TOP: Pressure 11. An open-tube manometer is used to measure the pressure in a flask. The atmospheric pressure is 756 torr and the Hg column is 8.5 cm higher on the open end. What is the pressure in the flask? a. 764.5 mmHg b. 841 cm Hg c. 841 torr d. 671 torr e. 747.5 mm Hg ANS: C OBJ: Determine gas pressure using manometric data. TOP: Pressure 12. The statement "At constant temperature, the volume occupied by a definite mass of a gas is inversely proportional to the applied pressure." is a statement of ____ Law. a. Charles's b. Boyle's c. Graham's d. Avogadro's e. Gay-Lussac's ANS: B OBJ: Name the gas Law. TOP: Boyle's Law: The Volume-Pressure Relationship 13. If the volume of a sample of Ne is tripled while the temperature is held constant, what happens to the pressure of the gas? a. It triples b. It stays the same. c. It doubles. d. It decreases to 1/3. e. It decreases to 1/2. ANS: D OBJ: Apply Boyle's Law to determine the change in pressure. TOP: Boyle's Law: The Volume-Pressure Relationship
Whitten 10e
Test Bank
394
14. A sample of oxygen occupies 47.2 liters under a pressure of 1240. torr at 25C. What volume would it occupy at 25C if the pressure were decreased to 730. torr? a. 27.8 L b. 29.3 L c. 32.3 L d. 47.8 L e. 80.2 L ANS: E OBJ: Apply Boyle's Law to determine the volume. TOP: Boyle's Law: The Volume-Pressure Relationship 15. A gas occupies 1.75 liters and exerts a pressure of 730. torr at a certain temperature. If the temperature is held constant, what volume must it occupy to exert a pressure of 820. torr? a. 0.641 L b. 1.56 L c. 3.44 L d. 0.291 L e. 1.08 L ANS: B OBJ: Apply Boyle's Law to determine the volume. TOP: Boyle's Law: The Volume-Pressure Relationship 16. Ammonia, NH3, is used to as fertilizer and as a refrigerant. What is the new pressure if 25.0 g of ammonia with a volume of 750 mL at 1.50 atm is expanded to 7.50 L at constant temperature? a. 15 atm b. 114 mm Hg c. 0.15 psi d. 6.67 atm e. 15 mm Hg ANS: B OBJ: Apply Boyle's Law to determine the pressure. TOP: Boyle's Law: The Volume-Pressure Relationship 17. The volume of a sample of a gas is 405 mL at 10.0 atm and 467 K. What volume will it occupy at 4.29 atm and the same temperature? a. 17.4 L b. 189 mL c. 174 mL d. 1047 mL e. 944 mL ANS: E OBJ: Apply Boyle's Law to determine the volume. TOP: Boyle's Law: The Volume-Pressure Relationship 18. A 5.00-L sample of a gas exerts a pressure of 1040. torr at 50.0C. In what volume would the same sample exert a pressure of 1.00 atm at 50.0C? a. 0.146 L b. 3.65 L c. 6.84 L d. 8.72 L e. 5.20 L Whitten 10e
Test Bank
395
ANS: C DIF: Harder Question OBJ: Apply Boyle's Law to determine the volume. TOP: Boyle's Law: The Volume-Pressure Relationship 19. A sample of oxygen occupies 47.2 liters under a pressure of 1240. torr at 25C. By what percent does the volume of this sample change if the pressure were decreased to 730. torr at 25C? a. 37.8% b. 41.1% c. 43.4% d. 46.1% e. 69.9% ANS: E DIF: Harder Question OBJ: Apply Boyle's Law to determine the change in volume. TOP: Boyle's Law: The Volume-Pressure Relationship 20. A sample of gas occupies a volume of 1.60 L at a pressure of 720. torr. What would be the pressure of this gas if it were compressed to 1.20 L at the same temperature? a. 540. torr b. 360. torr c. 180. torr d. 960. torr e. 1440 torr ANS: D OBJ: Apply Boyle's Law to determine the pressure. TOP: Boyle's Law: The Volume-Pressure Relationship 21. A sample of carbon monoxide, CO, occupies a volume of 350. mL and exerts a pressure of 1020. torr at 25C. If the volume expands to 500. mL with no temperature change, what pressure will the gas exert? a. 617 torr b. 827 torr c. 714 torr d. 938 torr e. 1457 torr ANS: C OBJ: Apply Boyle's Law to determine the pressure. TOP: Boyle's Law: The Volume-Pressure Relationship 22. A 6.25-L sample of gas exerts a pressure of 1.46 atm at 25C. What would be the pressure of this gas sample at 25C if it were compressed to a volume of 5.05 L? a. 1.81 atm b. 1.18 atm c. 21.6 atm d. 1.70 atm e. 0.280 atm ANS: A OBJ: Apply Boyle's Law to determine the pressure. TOP: Boyle's Law: The Volume-Pressure Relationship
Whitten 10e
Test Bank
396
23. The volume of a gas sample is 600. mL at 25C and a pressure of 2.04 atm. What would be the pressure of this sample if it were allowed to expand to 850. mL at 25C? a. 2.89 atm b. 3.10 atm c. 4.40 atm d. 1.44 atm e. 0.346 atm ANS: D OBJ: Apply Boyle's Law to determine the pressure. TOP: Boyle's Law: The Volume-Pressure Relationship 24. The statement "At constant pressure, the volume occupied by a definite mass of a gas is directly proportional to the absolute temperature." is a statement of ____ Law. a. Charles's b. Boyle's c. Graham's d. Avogadro's e. Gay-Lussac's ANS: A OBJ: Name the gas Law. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 25. If the volume of a sample of Ar gas is tripled while pressure is held constant, what happens to the absolute temperature? a. It remains constant. b. It decreases to 1/3. c. It triples. d. It increases nine-fold. e. It decreases to 1/6. ANS: C OBJ: Apply Charles's Law to determine the change in temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 26. Absolute zero is the temperature at which a. a graph of V versus 1/P intersects the 1/P-axis. b. gaseous helium liquefies. c. the straight line graph of V versus T intersects the T-axis. d. a graph of P versus 1/V intersects the 1/V-axis. e. none of these ANS: C DIF: Harder Question OBJ: Define absolute temperature in terms of Charles's Law. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 27. A gas sample occupies 4.20 L under a pressure of 800. torr at 350. K. At what temperature will it occupy 3.60 L at the same pressure? a. 7 K b. 300. K c. 408 K d. 300.C e. 770. K Whitten 10e
Test Bank
397
ANS: B OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 28. A temperature of 316.23C is equivalent to: a. 43.08K b. 143.08 K c. 689.38K d. 589.38 K e. none of these ANS: D OBJ: Convert between temperature units. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 29. Which of the following statements about Charles' Law is false? a. Doubling the absolute T doubles the volume at constant P and n. b. Absolute T and V are directly proportional. c. Tripling the volume of a gas causes the absolute T to triple at constant P and n. d. At constant P and n, changing the T from 100C to 200C causes the volume to double. e. At constant P and n, changing the T from 100 K to 200 K causes the volume to double. ANS: D OBJ: Interpret and apply Charles's Law. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 30. Radon is a radioactive gas found below ground. If a sample of radon occupies 29 mL at 25C, what volume will it occupy at 500 K? Assume constant pressure. a. 5140 mL b. 29 mL c. 49 mL d. 17 mL e. 500 mL ANS: C OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 31. A sample of nitrogen occupies 5.50 liters under a pressure of 900. torr at 25.0C. At what temperature will it occupy 10.0 liters at the same pressure? a. 32C b. 109C c. 154C d. 269C e. 370.C ANS: D OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale
Whitten 10e
Test Bank
398
32. A given mass of xenon gas has a volume of 200. mL at 25.0C and 760. torr. To what temperature must the xenon be heated to occupy 450. mL at 760. torr? a. 376C b. 398C c. 416C d. 512C e. 492C ANS: B OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 33. Ethylene, C2H4, is used to make plastic milk bottles. When the volume of 1000 g of ethylene at 25C is decreased from 40.0 L to 15.0 L, what is the new temperature assuming the pressure is held constant? a. 112 K b. 410 K c. 25C d. 522C e. 795 K ANS: A OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 34. A sample of a gas occupies 460. mL at 70.0C and 1.00 atmosphere. At what temperature would the gas occupy 650. mL at the same pressure? a. 154C b. 30.3C c. 212C d. 101C e. 188C ANS: C OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 35. A 300. mL sample of neon is confined under a pressure of 0.420 atm at 15.0C. At what temperature would it occupy 1.00 L at the same pressure? a. 187C b. 86.4C c. 380.C d. 687C e. 960.C ANS: D OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale
Whitten 10e
Test Bank
399
36. If 5.50 L of argon gas at 273C is heated at constant pressure to a temperature of 546C, what would be its new volume? a. 11.0 L b. 16.5 L c. 2.75 L d. 3.67 L e. 8.25 L ANS: E OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 37. Snoopy is inflated for the Macy's Thanksgiving parade with 50,000 L of He at 25C and 1.2 atm. What is the percent decrease in Snoopy's volume if the temperature drops to 4C before the parade? Assume constant pressure. a. 7.58% b. 10.1% c. 7.1% d. 21% e. 1.2% ANS: C OBJ: Apply Charles's Law to determine the change in volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 38. The temperature of a fixed amount of hydrogen gas is reduced from 20.0C to 20.0C at constant pressure. If the original volume of gas is 420. mL, what is the final volume? a. 466 mL b. 257 mL c. 363 mL d. 406 mL e. 392 mL ANS: C OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 39. Suppose you inhaled 1.00 liter of air at 30.0C (22F), and held this air long enough to heat it to body temperature, 37.0C. What would be the new volume of the air in the lungs assuming constant pressure? a. 0.972 L b. 0.811 L c. 1.23 L d. 1.02 L e. 1.28 L ANS: E OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale
Whitten 10e
Test Bank
400
40. 2.00 g of fluorine occupies 1.18 L at STP. What volume will it occupy at 14C and 1 atm? a. 1.20 L b. 2.73 L c. 5.89 L d. 1.12 L e. 6.20 L ANS: D OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 41. A gas sample occupies 1.00 L at 120.C and 1.00 atm. What volume will it occupy at STP? a. 1.14 L b. 1.44 L c. 0.846 L d. 0.782 L e. 0.695 L ANS: E OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 42. A gaseous sample has a volume of 3.88 L at 115C and 760. torr. What would be its volume at STP? a. 5.51 L b. 2.98 L c. 3.63 L d. 3.37 L e. 2.73 L ANS: E OBJ: Apply Charles's Law to determine volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 43. A sample of He gas has a volume of 373 mL at 0.0C and 825 torr. What would be its volume at STP? a. 405 mL b. 508 mL c. 344 mL d. 235 mL e. 1680 mL ANS: A OBJ: Apply Boyle's Law to determine the change in volume. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 44. By international agreement the standard temperature and pressure (STP) for gases is a. 25C and one atmosphere. b. 273.15 K and 760. torr. c. 298.15 K and 760. torr. d. 0C and 700. torr. e. 293 K and one atmosphere. ANS: B OBJ: Define STP. TOP: Standard Temperature and Pressure
Whitten 10e
Test Bank
401
45. A sample of neon, Ne, occupies 1700. mL at STP. At constant pressure, what temperature is necessary to increase the volume to 2100. mL? a. 14C b. 52C c. 32C d. 52C e. 64C ANS: E OBJ: Apply Charles's Law to determine temperature. TOP: Standard Temperature and Pressure 46. A sample of gas occupies 650. mL at STP. If the pressure remains constant, what volume will it occupy at a temperature of 65.0C? a. 776 mL b. 805 mL c. 487 mL d. 525 mL e. 910. mL ANS: B OBJ: Apply Charles's Law to determine volume. TOP: Standard Temperature and Pressure 47. A sample of helium occupies 5.00 L at STP. What volume will the sample occupy at 0.0C and 890. torr? a. 3.56 L b. 3.72 L c. 4.06 L d. 4.27 L e. 5.86 L ANS: D OBJ: Apply Boyle's Law to determine the volume. TOP: Standard Temperature and Pressure 48. A sample of a gas occupies 20.0 liters at STP. Under what pressure would it occupy 20.0 liters at 50.0C? a. 0.183 atm b. 1.18 atm c. 0.732 atm d. 3.71 atm e. 5.46 atm ANS: B OBJ: Apply the ideal gas law to determine pressure. TOP: The Combined Gas Law Equation
Whitten 10e
Test Bank
402
49. A sample of nitrogen occupies a volume of 546 mL at STP. What volume would the nitrogen occupy at 177C under a pressure of 380. torr? a. 91 mL b. 273 mL c. 900. mL d. 1.09 103 mL e. 1.80 103 mL ANS: E OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation 50. A sample of nitrogen occupies a volume of 300. mL under a pressure of 380. torr at 73C. What volume would the gas occupy at STP? a. 205 mL b. 180 mL c. 360 mL d. 150 mL e. 810 mL ANS: A OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation 51. Which of the following statements about the combined gas law is incorrect? a. At constant temperature the volume occupied by a definite mass of a gas varies inversely with the applied pressure. b. Doubling the volume and pressure of a sample of gas quadruples the absolute temperature. c. At constant pressure the volume occupied by a definite mass of a gas varies inversely with the absolute temperature. d. Halving the volume of a sample of gas while doubling the pressure leaves the absolute temperature unchanged. e. Doubling the volume and pressure of a sample of gas doubles the absolute temperature. ANS: E OBJ: Interpret and apply the ideal gas law. TOP: The Combined Gas Law Equation 52. A sample of a gas occupies 3.24 liters at 25.0C and 734 torr. What volume does it occupy at STP? a. 2.87 L b. 2.96 L c. 3.07 L d. 3.42 L e. 3.66 L ANS: A OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation
Whitten 10e
Test Bank
403
53. A sample of propane, C3H8, occupies 1.73 L when the pressure is 320 torr at 30C. What is the volume at STP? a. 656 mL b. 499 mL c. 5.09 L d. 3.70 L e. 808 mL ANS: A OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation 54. A sample of nitrogen occupies 200. mL at 27C when the pressure is 0.500 atm. What volume would it occupy at standard conditions? a. 91 mL b. 110. mL c. 127 mL d. 135 mL e. 440. mL ANS: A OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation 55. A sample of neon occupies 4.50 liters at 30.0C and 2.50 atmospheres. What pressure does the sample exert at 50C if the sample is compressed to 3.25 L? a. 5.77 atm b. 3.01 atm c. 1.92 atm d. 1.69 atm e. 3.69 atm ANS: E OBJ: Apply the ideal gas law to determine pressure. TOP: The Combined Gas Law Equation 56. A sample of helium occupies 1.40 L at standard conditions. What pressure will it exert in a 0.500 L vessel at 100.C? a. 624 torr b. 1.56 103 torr c. 2.91 103 torr d. 371 torr e. 4.05 103 torr ANS: C OBJ: Apply the ideal gas law to determine pressure. TOP: The Combined Gas Law Equation
Whitten 10e
Test Bank
404
57. A sample of a gas occupies 200. mL at STP. Under what pressure would this sample occupy 300. mL if the temperature were changed to 718C? a. 0.841 atm b. 0.966 atm c. 2.42 atm d. 1.76 atm e. 1.42 atm ANS: C OBJ: Apply the ideal gas law to determine pressure. TOP: The Combined Gas Law Equation 58. A sample of gas occupies 30.0 liters at STP. What will be its temperature in C if the volume is reduced to 22.5 liters under 3.50 atmospheres pressure? a. 212C b. 284C c. 386C d. 444C e. 516C ANS: D OBJ: Apply the ideal gas law to determine temperature. TOP: The Combined Gas Law Equation 59. A sample of a gas occupies 1.80 L at 10.C and 450. torr. What will be the temperature if the pressure is increased to 800. torr and the volume is decreased by 1/3? a. 99C b. 49C c. 174C d. 3.8C e. 224C ANS: C OBJ: Apply the ideal gas law to determine temperature. TOP: The Combined Gas Law Equation 60. A quantity of Xe occupies 121 mL at 300C and 1.09 atm. What will be the temperature if the volume is increased to 253 mL at 405 torr? a. 259 K b. 586 K c. 134 K d. 2449 K e. 306 K ANS: B OBJ: Apply the ideal gas law to determine temperature. TOP: The Combined Gas Law Equation
Whitten 10e
Test Bank
405
61. A sample of a gas occupies 60.0 mL at 10.0C and 720. torr. What pressure will the gas exert in a 101 mL sealed bulb at 25C? a. 1373 torr b. 171 torr c. 485 torr d. 377 torr e. 1069 torr ANS: C OBJ: Apply the ideal gas law to determine pressure. TOP: The Combined Gas Law Equation 62. A gas sample occupies 2.50 L at 125C and 2.06 atm. What will be its volume at 25C and 1.08 atm? a. 6.37 L b. 3.57 L c. 0.981 L d. 1.75 L e. 0.954 L ANS: B OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation 63. A sample of gas occupies 20.0 liters at 32C when the pressure is 0.750 atm. What will be its temperature in C if the volume increased to 25.0 liters at a pressure of 0.680 atm? a. 3.9C b. 309C c. 73C d. 346C e. 36C ANS: C OBJ: Apply the ideal gas law to determine temperature. TOP: The Combined Gas Law Equation 64. A sample of neon occupies 4.50 liters at 30.0C and 2.50 atmospheres. What volume will it occupy at 1000. torr and 300.C? a. 4.52 L b. 4.48 L c. 16.2 L d. 8.96 L e. 1.25 L ANS: C OBJ: Apply the ideal gas law to determine volume. TOP: The Combined Gas Law Equation
Whitten 10e
Test Bank
406
65. A 1 L sample of gas at 25C and 1 atm pressure is subjected to an increase in pressure and a decrease in temperature. The density of the gas ____. a. decreases b. increases c. remains the same d. becomes zero e. either increases or decreases, depending on the sizes of the pressure and temperature changes ANS: B OBJ: Apply the ideal gas law to understanding the change in density of a gas. TOP: Avogadro's Law and the Standard Molar Volume 66. Which of the following statements about Avogadro's Law is false? a. At constant P and T, volume and moles of gas are directly proportional. b. An equal number of moles of different gases occupy the same volume at STP. c. At constant T and P, doubling the moles of gas decreases the volume by half. d. One mole of He occupies 22.4 L at STP. e. At the same T and P, 2 mol of gas occupies twice the volume of one mole of gas. ANS: C OBJ: Interpret and apply Avogadro's Law. TOP: Avogadro's Law and the Standard Molar Volume 67. What volume will 12.40 grams of CO2 occupy at STP, if it behaves ideally? a. 6.31 L b. 8.46 L c. 4.42 L d. 11.7 L e. 9.68 L ANS: A OBJ: Apply Charles's Law to determine volume. TOP: Avogadro's Law and the Standard Molar Volume 68. Calculate the volume occupied by 0.588 g of NH3 at STP, if it behaves ideally. a. 0.502 L b. 0.368 L c. 0.621 L d. 0.775 L e. 0.804 L ANS: D OBJ: Apply the ideal gas law to determine volume. TOP: Avogadro's Law and the Standard Molar Volume 69. What is the volume occupied by 10.0 grams of NH3 at STP, if it behaves ideally? a. 10.6 L b. 13.2 L c. 14.3 L d. 14.9 L e. 15.8 L
Whitten 10e
Test Bank
407
ANS: B OBJ: Apply the ideal gas law to determine volume. TOP: Avogadro's Law and the Standard Molar Volume 70. What is the molecular weight of a gas if 0.104 gram of the gas occupies 48.7 mL at STP? a. 5.06 g/mol b. 28.2 g/mol c. 34.5 g/mol d. 40.0 g/mol e. 47.8 g/mol ANS: E OBJ: Apply the ideal gas law to determine molecular weight. TOP: Avogadro's Law and the Standard Molar Volume 71. What is the molecular weight of a gas if 5.00 grams of it occupies 2200. mL at STP? a. 50.9 g/mol b. 42.6 g/mol c. 59.6 g/mol d. 63.4 g/mol e. 68.0 g/mol ANS: A OBJ: Apply the ideal gas law to determine molecular weight. TOP: Avogadro's Law and the Standard Molar Volume 72. A sample of a gas with a mass of 6.87 g occupies 3.25 L at STP. What is the molecular weight? a. 5.77 g/mol b. 22.3 g/mol c. 129 g/mol d. 47.4 g/mol e. 2.11 g/mol ANS: D OBJ: Apply the ideal gas law to determine molecular weight. TOP: Avogadro's Law and the Standard Molar Volume 73. At STP, 4.00 L of a pure gaseous substance has a mass of 10.0 grams. The molecular weight of this substance is ____. a. 56.0 amu b. 67.4 amu c. 73.9 amu d. 89.6 amu e. 120. amu ANS: A OBJ: Apply the ideal gas law to determine molecular weight. TOP: Avogadro's Law and the Standard Molar Volume 74. A sample of nitrous oxide, N2O, occupies 16.5 L at STP. What is the mass of the sample? a. 18.9 g b. 22.1 g c. 28.6 g d. 32.4 g e. 46.0 g Whitten 10e
Test Bank
408
ANS: D OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Avogadro's Law and the Standard Molar Volume 75. The simplest formula for a compound is NO2. If 46.0 grams of the gas occupies 11.2 liters at standard conditions, the mass of one mole of the compound is ____. a. 46.0 g/mol b. 23.0 g/mol c. 92.0 g/mol d. 30.0 g/mol e. 62.0 g/mol ANS: C OBJ: Apply the ideal gas law to determine molecular weight. TOP: Avogadro's Law and the Standard Molar Volume 76. A 7.97 g sample of gas occupies 5.25 L at STP. What is the formula of the gas? a. CO2 b. NO c. Cl2 d. PCl3 e. N2H4 ANS: E OBJ: Apply the ideal gas law to determine the identity of a gas. TOP: Avogadro's Law and the Standard Molar Volume 77. What mass of methane, CH4, is contained in a 500.-mL sample of CH4 at STP? a. 0.212 g b. 0.268 g c. 0.357 g d. 0.390 g e. 0.407 g ANS: C OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Avogadro's Law and the Standard Molar Volume 78. A sample of NO2 occupies 11,200 mL at STP. What is the mass of the sample? a. 21.0 g b. 18.6 g c. 23.0 g d. 38.6 g e. 42.4 g ANS: C OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Avogadro's Law and the Standard Molar Volume 79. If 4.00 g of a gas occupies 1.12 liters at STP, what is the mass of 2.00 moles of the gas? a. 20.0 g b. 40.0 g c. 80.0 g d. 160. g e. 120. g Whitten 10e
Test Bank
409
ANS: D OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Avogadro's Law and the Standard Molar Volume 80. Given the mass of one mole of gaseous NO is 30.0 grams/mole, calculate the density of NO in grams/liter at STP. a. 1.12 g/L b. 0.987 g/L c. 2.17 g/L d. 1.34 g/L e. 1.60 g/L ANS: D OBJ: Apply the ideal gas law to determine the density of a gas. TOP: Avogadro's Law and the Standard Molar Volume 81. Calculate the density of O2, in g/L, at STP. a. 0.810 g/L b. 1.43 g/L c. 1.62 g/L d. 0.714 g/L e. 1.14 g/L ANS: B OBJ: Apply the ideal gas law to determine the density of a gas. TOP: Avogadro's Law and the Standard Molar Volume 82. The simplest formula for a compound is NO2. If 46.0 grams of the gas occupies 11.2 liters at standard conditions, the molecular formula of the gas is ____. a. NO2 b. N2O4 c. N3O6 d. NO e. N2O ANS: B OBJ: Apply the ideal gas law to determine the identity of a gas. TOP: Avogadro's Law and the Standard Molar Volume 83. Assuming Ideal Gas behavior, for which of the following gases does PV/nT = R, 0.08206 L atm/mol K? a. CO2 b. H2 c. Ar d. C2H2 e. all of these ANS: E OBJ: Identify the gases which follow the ideal gas law. TOP: Summary of Gas Laws: The Ideal Gas Equation
Whitten 10e
Test Bank
410
84. Which of the following statements about the ideal gas law is false? a. The Ideal Gas Law is the most accurate predictor of gas behavior. b. Boyle's, Charles', and Avogadro's Laws are combined in it. c. All gases are assumed to behave in an ideal way. d. The Ideal Gas Law relates P, V, T and moles of gas. e. Under the same conditions, H2 and NH3 would be expected to be the same way. ANS: A OBJ: Interpret and apply the ideal gas law. TOP: Summary of Gas Laws: The Ideal Gas Equation 85. Evaluate R in units of mL torr/mol K. (Hint: Consider one mole of an ideal gas at STP.) R = ____ a. b. c. d. e.
6.24 104 82.1 0.108 4.02 102 7.67 102
ANS: A OBJ: Convert the units of the gas constant. TOP: Summary of Gas Laws: The Ideal Gas Equation 86. Which set of units for the following values of R is incorrect? a. 0.08206 Latm/molK b. 8.314 kPadm3/molK c. 62.4 Ltorr/molK d. 22.4 L/molK e. 82.1 mLatm/molK ANS: D OBJ: Convert the units of the gas constant. TOP: Summary of Gas Laws: The Ideal Gas Equation 87. Ten (10.0) moles of a gas are contained in a 10.0 L container at 273 K. Calculate the pressure of the gas. a. 2.24 atm b. 4.48 atm c. 11.2 atm d. 15.7 atm e. 22.4 atm ANS: E OBJ: Apply the ideal gas law to determine pressure. TOP: Summary of Gas Laws: The Ideal Gas Equation 88. What is the pressure of 64.0 g of oxygen gas in a 1.50-L container at 37C? a. 4.12 atm b. 25.8 atm c. 51.6 atm d. 19.6 atm e. 8.2 atm Whitten 10e
Test Bank
411
ANS: B OBJ: Apply the ideal gas law to determine pressure. TOP: Summary of Gas Laws: The Ideal Gas Equation 89. Assume that 454 g (1.00 lb) of Dry Ice (solid CO2) is placed into an evacuated 50.0 L closed tank. What is the pressure in the tank in atmospheres at 45.0C after all the solid has vaporized? a. 14.6 atm b. 5.38 atm c. 3.14 atm d. 8.41 atm e. 10.6 atm ANS: B OBJ: Apply the ideal gas law to determine pressure. TOP: Summary of Gas Laws: The Ideal Gas Equation 90. What is the volume that 57.0 grams of F2 would occupy at 227C and 1.50 atm? a. 1.06 L b. 18.6 L c. 41.0 L d. 82.1 L e. 106 L ANS: C OBJ: Apply the ideal gas law to determine volume. TOP: Summary of Gas Laws: The Ideal Gas Equation 91. A dentist has a 5.00 L cylinder of "laughing gas", N2O, at 20.0 atm and 25C. What mass of gas is contained in it? a. 8.31 g b. 4.09 g c. 1660 g d. 696 g e. 180 g ANS: E OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 92. Calculate the volume that 256 grams of SO2 occupies at 227C under a pressure of 1520 torr. a. 1.94 L b. 22.4 L c. 81.9 L d. 146.7 L e. 194 L ANS: C OBJ: Apply the ideal gas law to determine volume. TOP: Summary of Gas Laws: The Ideal Gas Equation
Whitten 10e
Test Bank
412
93. Calculate the volume occupied by 37.0 grams of SO2 at 215C and 1340 torr. a. 7.62 L b. 9.09 L c. 11.6 L d. 13.1 L e. 15.0 L ANS: D OBJ: Apply the ideal gas law to determine volume. TOP: Summary of Gas Laws: The Ideal Gas Equation 94. What is the volume occupied by 20.0 grams of NH3 at 500.C and 1140 torr? a. 29.8 L b. 32.2 L c. 49.8 L d. 65.4 L e. 92.4 L ANS: C OBJ: Apply the ideal gas law to determine volume. TOP: Summary of Gas Laws: The Ideal Gas Equation 95. How many moles of Argon would occupy 75 mL at 33C and 1.07 atm? a. 3.19 b. 2.96 102 c. 3.19 103 d. 3.15 105 e. 0.313 ANS: C OBJ: Apply the ideal gas law to determine moles of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 96. A sample of a gas occupies a volume of 350. mL at 3000. torr and 25C. Calculate the number of moles of gas present. a. 5.65 102 mol b. 8.39 103 mol c. 1.25 102 mol d. 1.38 102 mol e. 2.19 103 mol ANS: A OBJ: Apply the ideal gas law to determine moles of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 97. How many oxygen atoms are contained in a sample of O2 that occupies 1500. mL at 50.0C and 1.00 atm pressure? a. 1.75 1023 b. 3.87 1023 c. 3.40 1022 d. 8.91 1022 e. 6.81 1022
Whitten 10e
Test Bank
413
ANS: E DIF: Harder Question OBJ: Apply the ideal gas law to determine the atoms of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 98. The volume of a sample of nitrogen is 6.00 liters at 35C and 740. torr. How many grams of nitrogen, N2, are present in the sample? a. 8.28 g b. 6.48 g c. 6.82 g d. 3.24 g e. 4.14 g ANS: B OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 99. Calculate the mass of a 10.-liter sample of C2H6 at 459C under a pressure of 760. torr. a. 2.5 g b. 5.0 g c. 7.5 g d. 10 g e. 8.2 g ANS: B OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 100. What mass of CH4 is contained in a 500.-mL sample of CH4 at 40.0C and 300. torr? a. 0.0870 g b. 0.165 g c. 0.322 g d. 0.734 g e. 1.06 g ANS: B OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 101. Calculate the density of O2 gas (in g/L) at 1.22 atm and 25C. a. 1.74 g/L b. 1.60 g/L c. 0.871 g/L d. 19.0 g/L e. 0.798 g/L ANS: B OBJ: Apply the ideal gas law to determine the density of a gas. TOP: Summary of Gas Laws: The Ideal Gas Equation
Whitten 10e
Test Bank
414
102. The standard molar volume of an ideal gas is 22.414 liters per mole at STP. Some real gases can deviate significantly from this value. Calculate the standard molar volume of sulfur hexafluoride (SF6), density = 6.65 g/L at STP. a. 21.963 L b. 971.27 L c. 23.064 L d. 1.53 g/L e. 0.766 g/L ANS: D OBJ: Convert density at STP to a standard molar volume. TOP: Summary of Gas Laws: The Ideal Gas Equation 103. At 150.C and 1.00 atm, 500. mL of a vapor has a mass of 0.4183 g. What is the molecular weight of the compound? a. 55.0 g/mol b. 58.0 g/mol c. 62.0 g/mol d. 65.0 g/mol e. 29.1 g/mol ANS: E OBJ: Apply the ideal gas law to determine molecular weight. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 104. 0.397-g sample of a gas occupies a volume of 275 mL at 10.C and 365 torr. What is the molecular weight of the gas? a. 85.9 g/mol b. 72.8 g/mol c. 69.8 g/mol d. 61.3 g/mol e. 59.8 g/mol ANS: C OBJ: Apply the ideal gas law to determine molecular weight. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 105. A sample of a gas has a mass of 1.73 g and occupies 2.00 L at 122C and 1.00 atm. What is the molecular weight? a. 28.1 g/mol b. 8.66 g/mol c. 0.036 g/mol d. 1.73 g/mol e. 16.2 g/mol ANS: A OBJ: Apply the ideal gas law to determine molecular weight. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances
Whitten 10e
Test Bank
415
106. A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-gram sample of the gas occupies a volume of 1.00 liter and exerts a pressure of 1.26 atmospheres at 4.0C. What is its molecular formula? a. NO b. NO2 c. N3O6 d. N2O4 e. N2O5 ANS: D OBJ: Apply the ideal gas law to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 107. A laboratory technician boils an unknown volatile liquid at 56C and atmospheric pressure. The volume of her flask is 2.00 L and when the liquid is gone, leaving only vapor, the mass of the gas is 3.23 g. What is the molecular weight of the gas? a. 38 g/mol b. 44 g/mol c. 1.41 g/mol d. 0.44 g/mol e. 182 g/mol ANS: B OBJ: Apply the ideal gas law to determine molecular weight. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 108. A gaseous compound is 30.4% nitrogen and 69.6% oxygen. A 6.06-gram sample of gas occupies a volume of 1.00 liter and exerts a pressure of 1.26 atmospheres at 40.0C. What is its molecular formula? a. NO b. NO2 c. N3O6 d. N2O4 e. N2O5 ANS: D OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 109. Analysis of a volatile liquid shows that it contains 62.04% carbon, 10.41% hydrogen, and 27.54% oxygen by mass. At 150.C and 1.00 atm, 500. mL of the vapor has a mass of 0.8365 g. What is the molecular formula of the compound? a. C2H5OH b. C3H6O c. C6H12O2 d. C12H24O4 e. C4H6O ANS: B OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances
Whitten 10e
Test Bank
416
110. Analysis of a volatile liquid showed that it is 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen by mass. A separate 0.345-gram sample of its vapor occupied 120. mL at 100.C and 1.00 atm. What is the molecular formula for the compound? a. C2H4O b. C4H8O2 c. C3H6O2 d. C6H12O4 e. C5H12O ANS: B OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 111. Analysis of a sample of a gaseous compound shows that it contains 81.8% C and 18.2% H by mass. At standard conditions, 112 mL of the compound weighs 0.220 g. What is the molecular formula for the compound? a. C2H4 b. C4H8 c. C3H8 d. C3H6 e. C6H16 ANS: C OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 112. A gaseous compound is 78.26% boron and 21.74% hydrogen by mass. A 0.600-g sample of it occupies 487 mL at STP. What is the molecular formula for the gas? a. BH3 b. B2H6 c. B3H9 d. B2H4 e. B3H6 ANS: B OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 113. A gas consists of 14.9% P and 85.1% Cl. A 2.184 g sample of this gas occupies 500 mL at 460 torr and 78C. What is the molecular formula? a. PCl b. P2Cl10 c. PCl3 d. PCl5 e. PCl4 ANS: D OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances
Whitten 10e
Test Bank
417
114. A gaseous compound containing only nitrogen and oxygen is 63.64% N and 36.36% O by weight. At standard conditions 196 mL of the gas weighs 0.385 grams. What is the molecular formula of the gas? a. NO b. N2O c. N2O4 d. NO2 e. N4O2 ANS: B OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 115. A gaseous compound is 52.14% C, 13.13% H and 34.73% O by mass. At STP 325 mL of the gas weighs 0.668 g. What is the molecular formula for this compound? a. C2H6O b. C3H5O c. C4H8O d. C4H12O e. C4H12O2 ANS: A OBJ: Apply the ideal gas law and percent composition to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 116. A 2.08-gram sample of a gaseous compound contains 1.92 grams of carbon and 0.16 gram of hydrogen. At STP, the same sample occupies a volume of 1793 mL. What is the molecular formula for the compound? a. C4H8 b. C2H2 c. C3H9 d. C4H4 e. C2H4 ANS: B OBJ: Apply the ideal gas law and composition data to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 117. A 0.580-g sample of a compound containing only carbon and hydrogen contains 0.480 g of carbon and 0.100 g of hydrogen. At STP 33.6 mL of the gas has a mass of 0.087 g. What is the molecular formula for the compound? a. CH3 b. C2H6 c. C2H5 d. C4H10 e. C4H12 ANS: D OBJ: Apply the ideal gas law and composition data to determine the identity of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances
Whitten 10e
Test Bank
418
118. A 10.0-L flask contains 0.400 mole of H2, 0.300 mole of He and 0.500 mole of Ne at 35.0C. What is the total pressure in the flask? a. 2.53 atm b. 4.05 atm c. 3.03 atm d. 1.01 atm e. 0.345 atm ANS: C OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the total pressure. TOP: Dalton's Law of Partial Pressures 119. A mixture of gas consists of 5.0 g CH4, 5.0 g C2H2, and 5.0 g C2H4. What are the mole fractions of each?
a. b. c. d. e.
XCH4 0.321 0.333 0.217 0.567 0.457
XC2H2 0.192 0.333 0.375 0.137 0.281
XC2H4 0.177 0.333 0.408 0.326 0.262
ANS: E OBJ: Calculate mole fractions given the grams of each component. TOP: Dalton's Law of Partial Pressures 120. A 5.00 L container contains CH4, H2, and Xe at 35C with a total pressure of 1.81 atm. If there are equal moles of each gas, what is the partial pressure of H2? a. 0.603 atm b. 0.034 atm c. 1.81 atm d. 3.05 atm e. 0.362 atm ANS: A OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine partial pressures. TOP: Dalton's Law of Partial Pressures 121. A 10.0-L flask contains 0.400 mole of H2, 0.300 mole of He and 0.500 mole of Ne at 35.0C. What is the partial pressure of the Ne? a. 1.26 atm b. 3.03 atm c. 1.05 atm d. 1.69 atm e. 0.144 atm ANS: A OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine partial pressure. TOP: Dalton's Law of Partial Pressures
Whitten 10e
Test Bank
419
122. What is the pressure exerted by a mixture of 14.0 grams of N2, 71.0 grams of Cl2, and 16.0 grams of He in a 50.0-liter container at 0C? a. 2.47 atm b. 6.80 atm c. 14.1 atm d. 4.66 atm e. 0.687 atm ANS: A OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the total pressure. TOP: Dalton's Law of Partial Pressures 123. What is the pressure exerted by a mixture of 1.0 g H2 and 5.0 g He when confined to a volume of 5.0 liters at 20.C? a. 12.6 atm b. 8.4 atm c. 3.61 atm d. 10.4 atm e. 6.5 atm ANS: B OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the total pressure. TOP: Dalton's Law of Partial Pressures 124. A mixture of gases containing 21.0 g of N2, 106.5 g of Cl2 and 12.0 g of He at 14C is in a 50.0-L container. What is the total pressure in the vessel? a. 1.8 atm b. 2.2 atm c. 2.5 atm d. 2.7 atm e. 3.2 atm ANS: C OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the total pressure. TOP: Dalton's Law of Partial Pressures 125. A mixture of gas contains 0.251 g Ar and 1.95 g Xe and has a total pressure of 2.33 atm. What are the partial pressures of each gas?
a. b. c. d. e.
PAr (atm) 1.61 0.72 1.17 0.27 0.30
PXe (atm) 0.72 1.61 1.16 2.06 2.03
ANS: B OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine partial pressures. TOP: Dalton's Law of Partial Pressures
Whitten 10e
Test Bank
420
126. A mixture of gases containing 21.0 g of N2, 106.5 g of Cl2, and 12.0 g of He at 14C is in a 50.0-L container. What is the partial pressure of N2? a. 0.501 atm b. 0.707 atm c. 0.448 atm d. 0.353 atm e. 0.398 atm ANS: D OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine partial pressure. TOP: Dalton's Law of Partial Pressures 127. A mixture of gases containing 26.0 g SO2, 4.0 g H2, and 20.2 g Ne at 23C is in a 5.00-L container. What is the partial pressure of H2? a. 1.94 atm b. 19.5 atm c. 4.86 atm d. 9.72 atm e. 0.755 atm ANS: D OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine partial pressure. TOP: Dalton's Law of Partial Pressures 128. A mixture of gases containing 21.0 g of N2, 106.5 g of Cl2, and 12.0 g of He at 21C is in a 8.00-L container. What is the partial pressure of He? a. 2.26 atm b. 4.53 atm c. 9.05 atm d. 5.55 atm e. 0.647 atm ANS: C OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine partial pressure. TOP: Dalton's Law of Partial Pressures 129. What is the mole fraction of O2 in a mixture of 2.00 g He, 12.0 g O2, and 17.0 g N2? a. 0.608 b. 0.253 c. 0.410 d. 0.200 e. 0.267 ANS: B OBJ: Calculate a mole fraction given the grams of each component. TOP: Dalton's Law of Partial Pressures 130. A mixture of gases consists of 2.00 g He, 12.0 g O2, and 17.0 g N2. What is the mole fraction of N2 in this mixture? a. 0.267 b. 0.506 c. 0.253 d. 0.410 e. 0.208
Whitten 10e
Test Bank
421
ANS: D OBJ: Calculate a mole fraction given the grams of each component. TOP: Dalton's Law of Partial Pressures 131. A mixture of 16.0 g of He, 21.0 g of N2, and 16.0 g of O2 at 25C is in a 75.0-L container. What are the mole fractions of each of these three gases? XHe a. b. c. d. e.
0.842 0.889 0.800 0.762 0.952
0.158 0.167 0.150 0.143 0.762
0.105 0.111 0.100 0.0952 0.143
ANS: D OBJ: Calculate mole fractions given the grams of each component. TOP: Dalton's Law of Partial Pressures 132. A 10.0-liter vessel contains gas A at a pressure of 300. torr. A 3.0-liter vessel contains gas B at a pressure of 400. torr. Gas A is forced into the second vessel. Calculate the resulting pressure in torr. Assume temperature remains constant. a. 1000 torr b. 1400 torr c. 1800 torr d. 2000 torr e. 2300 torr ANS: B OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the total pressure. TOP: Dalton's Law of Partial Pressures 133. A 151-mL sample of O2 was collected over water at 21C when the barometric pressure was 742 torr. What mass of O2 was contained in the sample? The vapor pressure of H2O at 21C is 18.7 torr. a. 2.21 g b. 0.042 g c. 0.19 g d. 1.12 g e. 0.86 g ANS: C OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the mass of a gas collected over water. TOP: Dalton's Law of Partial Pressures 134. A 75 mL sample of CO2 is collected over water at 25C when the atmospheric pressure is 1.05 atm. How many moles of CO2 are present? The vapor pressure of water at 25C is 24.3 torr. a. 3.12 b. 0.0372 c. 0.00312 d. 2.37 e. 0.0322
Whitten 10e
Test Bank
422
ANS: C OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the moles of a gas collected over water. TOP: Dalton's Law of Partial Pressures 135. A 300.-mL sample of hydrogen, H2, was collected over water at 21C on a day when the barometric pressure was 748 torr. What mass of hydrogen is present? The vapor pressure of water is 19 torr at 21C. a. 0.0186 g b. 0.0241 g c. 0.0213 g d. 0.0269 g e. 0.0281 g ANS: B OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the mass of a gas collected over water. TOP: Dalton's Law of Partial Pressures 136. A 500.-mL sample of oxygen, O2, was collected by displacement of water at 24C under a barometric pressure of 738 torr. What mass of dry oxygen was collected? The vapor pressure of water at 24C is 22 torr. a. 0.245 g b. 0.310 g c. 0.319 g d. 0.619 g e. 0.637 g ANS: D OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the mass of a gas collected over water. TOP: Dalton's Law of Partial Pressures 137. A 5.42-liter sample of gas was collected over water when the temperature was 24C and the barometric pressure was 706 torr. The dry sample of gas had a mass of 5.60 g. What is the mass of three moles of the dry gas? The vapor pressure of water at 24C is 22 torr. a. 7.0 g b. 14 g c. 28 g d. 81 g e. 84 g ANS: E OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the mass of a gas collected over water. TOP: Dalton's Law of Partial Pressures 138. A sample of hydrogen collected by displacement of water occupied 30.0 mL at 24.0C on a day when the barometric pressure was 736 torr. What volume would the hydrogen occupy if it were dry and at STP? The vapor pressure of water at 24.0C is 22.4 torr. a. 32.4 mL b. 21.6 mL c. 36.8 mL d. 25.9 mL e. 27.6 mL Whitten 10e
Test Bank
423
ANS: D OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the volume of a gas collected over water. TOP: Dalton's Law of Partial Pressures 139. A 300.-mL sample of hydrogen, H2, was collected over water at 21C on a day when the barometric pressure was 748 torr. What volume will the dry hydrogen occupy at STP? The vapor pressure of water is 19 torr at 21C. a. 267 mL b. 261 mL c. 256 mL d. 276 mL e. 282 mL ANS: A OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the volume of a gas collected over water. TOP: Dalton's Law of Partial Pressures 140. A sample of oxygen collected over water at 32.0C and 752 torr has a volume of 0.627 liters. What volume would the dry oxygen occupy under standard conditions? The vapor pressure of water at 32.0C is 35.7 torr. a. 0.529 L b. 0.644 L c. 0.556 L d. 0.609 L e. 0.487 L ANS: A OBJ: Apply the ideal gas law and Dalton's Law of partial pressures to determine the volume of a gas collected over water. TOP: Dalton's Law of Partial Pressures 141. Which one of the statements below about the following reaction is false? CH4(g) + 2O2(g) CO2(g) + 2H2O(g) a. Every methane molecule that reacts produces two water molecules. b. If 16.0 g of methane react with 32.0 g of oxygen, the maximum amount of CO2 produced will be 22.0 g. c. If 11.2 liters of methane react with an excess of oxygen, the volume of CO2 produced at STP is (44/16)(11.2) liters. d. If 16.0 g of methane react with 64.0 g of oxygen, the combined masses of the products will be 80.0 g. e. If 22.4 liters of methane at STP react with 64.0 g of oxygen, 22.4 L (STP) of CO2 can be produced. ANS: C OBJ: Identify the incorrect interpretation of a balanced gaseous chemical reaction. TOP: Mass-Volume Relationships in Reactions Involving Gases
Whitten 10e
Test Bank
424
142. Consider the following reaction and identify the false statement. C2H2 + N2 2HCN a. b. c. d. e.
To produce exactly 22.4 L of HCN requires the complete reaction of 28 g of N2. One mol C2H2 of reacts with one mol N2 to produce 2 mol HCN. 26 g of C2H2 reacts to yield 44.8 L of HCN at STP. At STP, 22.4 L of C2H2 reacts to yield 44.8 L HCN. At STP, 22.4 L of N2 reacts to yield 44.8 L HCN.
ANS: A OBJ: Identify the incorrect interpretation of a balanced gaseous chemical reaction. TOP: Mass-Volume Relationships in Reactions Involving Gases 143. Assume that ammonia can be prepared by the following reaction in the gas phase at STP. If the reaction conditions are maintained at STP, which one of the following statements is incorrect? N2 + 3H2 2NH3 a. b. c. d.
22.4 L of N2 reacts with 3(22.4) L of H2 to form 2(22.4) L of NH3. 273 L of N2 reacts with 819 L of H2 to form 546 L of NH3. 28.0 g of N2 reacts with 6.0 g of H2 to form 44.8 L of NH3. A maximum of 273 L of NH3 can be prepared from 546 L of N2, given an adequate supply of H2. e. 1 mole of N2 reacts with 3 moles of H2 to form 2 moles of NH3 . ANS: D OBJ: Identify the incorrect interpretation of a balanced gaseous chemical reaction. TOP: Mass-Volume Relationships in Reactions Involving Gases 144. What volume of hydrogen (STP) is produced by dissolving one-half mole of aluminum in sulfuric acid? 2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g) a. b. c. d. e.
14.9 L 16.8 L 22.4 L 29.9 L 67.2 L
ANS: B OBJ: Use the balanced gaseous chemical reaction to determine volume of reactant. TOP: Mass-Volume Relationships in Reactions Involving Gases 145. What volume of O2 would be required to react with excess SO2 at STP to produce 0.500 mole of SO3? 2SO2(g) + O2(g) 2SO3(g) a. b. c. d. e.
44.8 L 22.4 L 33.6 L 5.60 L 11.2 L
ANS: D OBJ: Use the balanced gaseous chemical reaction to determine volume of reactant. TOP: Mass-Volume Relationships in Reactions Involving Gases
Whitten 10e
Test Bank
425
146. What total volume of gas (at STP) is produced by the electrolysis of 4 moles of H2O? 2H2O(g) 2H2(g) + O2(g) a. b. c. d. e.
67.2 L 134.4 L 3.0 L 112 L 5.0 L
ANS: B OBJ: Use the balanced gaseous chemical reaction to determine total volume of products. TOP: Mass-Volume Relationships in Reactions Involving Gases 147. Consider the following gas phase reaction. 4HCl(g) + O2(g) 2Cl2(g) + 2H2O(g) What volume of chlorine at STP can be prepared from the reaction of 600. mL of gaseous HCl, measured at STP, with excess O2, assuming that all the HCl reacts? a. 150. mL b. 267 mL c. 300. mL d. 425 mL e. 600. mL ANS: C OBJ: Use the balanced gaseous chemical reaction to determine volume of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 148. What volume of N2 is required to produce 18.3 L of NH3 at STP? 3H2(g) + N2(g) 2NH3(g) a. b. c. d. e.
27.5 L 18.3 L 9.15 L 22.4 L 12.2 L
ANS: C OBJ: Use the balanced gaseous chemical reaction to determine volume of reactant. TOP: Mass-Volume Relationships in Reactions Involving Gases 149. If 3.25 liters of ammonia react with an excess of oxygen at 500.C and 5.00 atm pressure, what volume of steam will be produced at the same temperature and pressure? 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) a. b. c. d. e.
2.04 L 2.17 L 3.33 L 4.14 L 4.88 L
ANS: E OBJ: Use the balanced gaseous chemical reaction to determine volume of product. TOP: Mass-Volume Relationships in Reactions Involving Gases
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150. Calculate the weight of KClO3 that would be required to produce 29.52 liters of oxygen measured at 127C and 760. torr. 2KClO3(s) a. b. c. d. e.
2KCl(s) + 3O2(g)
7.82 g 12.2 g 14.64 g 24.4 g 73.5 g
ANS: E DIF: Harder Question OBJ: Use the balanced gaseous chemical reaction to determine mass of reactant. TOP: Mass-Volume Relationships in Reactions Involving Gases 151. What volume of NO (STP) can be produced by dissolving 62.1 grams of lead in nitric acid? 3Pb + 8HNO3 3Pb(NO3)2 + 2NO + 4H2O a. b. c. d. e.
1.12 L 1.68 L 2.24 L 3.36 L 4.48 L
ANS: E OBJ: Use the balanced gaseous chemical reaction to determine volume of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 152. What volume of dry gaseous HBr at STP can be obtained from the reaction of 81.2 g of PBr3 with excess water? PBr3 + 3H2O H3PO3 + 3HBr(g) a. b. c. d. e.
6.72 L 15.2 L 17.4 L 26.4 L 20.2 L
ANS: E OBJ: Use the balanced gaseous chemical reaction to determine volume of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 153. If sufficient acid is used to react completely with 3.78 grams of zinc, what volume of hydrogen would be produced at STP? Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g) a. b. c. d. e.
1.14 L 1.29 L 1.38 L 1.45 L 1.53 L
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ANS: B OBJ: Use the balanced gaseous chemical reaction to determine volume of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 154. A 0.720-gram sample, known to contain only CaCO3 and BaCO3, was heated until the carbonates were decomposed to oxides as indicated. After heating, the mass of the solid residue was 0.516 gram. What volume of CO2, measured at STP, was produced by the reactions?
a. b. c. d. e.
CaCO3(s)
CaO(s) + CO2(g)
BaCO3(s)
BaO(s) + CO2(g)
104 mL 168 mL 284 mL 486 mL 627 mL
ANS: A DIF: Harder Question OBJ: Apply the ideal gas law to determine the mass of a gas. TOP: Mass-Volume Relationships in Reactions Involving Gases 155. What volume of dry silicon tetrafluoride (at STP) can be produced by the complete reaction of 89 g of CaSiO3? CaSiO3(s) + 6HF(g) CaF2(s) + SiF4(g) + 3H2O a. b. c. d. e.
29.2 L 22.4 L 0.767 L 17.2 L 104 L
ANS: D OBJ: Use the balanced gaseous chemical reaction to determine volume of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 156. Consider the following gas phase reaction. 4HCl(g) + O2(g) 2Cl2(g) + 2H2O(g) What mass of chlorine can be prepared from the reaction of 600. mL of gaseous HCl, measured at STP, with excess O2, assuming that all the HCl reacts? a. 190. g b. 0.475 g c. 0.686 g d. 0.951 g e. 1.42 g ANS: D OBJ: Use the balanced gaseous chemical reaction to determine mass of product. TOP: Mass-Volume Relationships in Reactions Involving Gases
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157. Magnesium reacts with ammonia, NH3, at high temperatures to produce solid magnesium nitride, Mg3N2, and hydrogen. How many grams of magnesium react with 16,400 mL (STP) of ammonia? 3Mg(s) + 2NH3(g) a. b. c. d. e.
Mg3N2(s) + 3H2(g)
11.6 g 26.7 g 34.2 g 22.9 g 19.6 g
ANS: B OBJ: Use the balanced gaseous chemical reaction to determine mass of reactant. TOP: Mass-Volume Relationships in Reactions Involving Gases 158. A sample of iron was dissolved in hydrochloric acid. The liberated hydrogen was collected by displacement of water. The hydrogen occupied 262 mL at 26C. The barometric pressure was 748 torr. What mass of iron was dissolved? The vapor pressure of water is 25 torr at 26C. Fe(s) + 2HCl(aq) FeCl2(aq) + H2(g) a. b. c. d. e.
0.284 g 0.414 g 0.496 g 0.549 g 0.565 g
ANS: E DIF: Harder Question OBJ: Use Dalton's law of partial pressures and the balanced gaseous chemical reaction to determine mass of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 159. A 4.52-gram sample containing only CaCO3 and MgCO3 was heated to decompose the carbonates. The liberated CO2 occupied 1.36 liters at 800.C under a pressure of 3.30 atmospheres. What mass of CaCO3 was contained in the original sample?
a. b. c. d. e.
CaCO3(s)
CaO(s) + CO2(g)
MgCO3(s)
MgO(s) + CO2(g)
1.3 g 2.4 g 1.5 g 3.2 g 2.7 g
ANS: C DIF: Harder Question OBJ: Apply the ideal gas law and the balanced chemical equations to determine moles of a gas and relate the moles of gas to amounts of reactants. TOP: Mass-Volume Relationships in Reactions Involving Gases
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160. A 10.0 g sample of CaCO3 is placed in a 10 L container and heated to 500 K. What is the pressure in the container, assuming all the CaCO3 reacts? CaCO3(s) CaO(s) + CO2(g) a. b. c. d. e.
4.1 atm 0.19 atm 11 atm 42 atm 0.41 atm
ANS: E OBJ: Use the balanced gaseous chemical reaction to determine the pressure of product. TOP: Mass-Volume Relationships in Reactions Involving Gases 161. Silver oxide decomposes completely at temperatures in excess of 300C to produce metallic silver and oxygen gas. A 1.60-gram sample of impure Ag2O gives 72.1 mL of O2 measured at STP. What is the percentage of Ag2O in the original sample? 2Ag2O(s) a. b. c. d. e.
4Ag(s) + O2(g)
79.6% 62.0% 86.4% 93.3% 73.3%
ANS: D OBJ: Use the balanced gaseous chemical reaction and volume of product gases to determine the percentage of metal in a sample. TOP: Mass-Volume Relationships in Reactions Involving Gases 162. At the same ____, the molecules of all samples of ideal gases have the same average kinetic energies. a. volume b. pressure c. mass d. density e. temperature ANS: E OBJ: Apply the kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 163. The average kinetic energy of ideal gas molecules is directly proportional to the ____. a. volume of the sample b. pressure of the sample c. mass of the molecule d. density of the sample e. absolute temperature of the sample ANS: E OBJ: Apply kinetic-molecular theory. TOP: The Kinetic-Molecular Theory
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164. Which gas law cannot be explained by the Kinetic Molecular Theory? a. Boyle's Law b. Dalton's Law c. Charles' Law d. Avogadro's Law e. all of these can be explained by Kinetic Molecular Theory ANS: E OBJ: Know the relationship between the gas laws and the kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 165. All of the following statements, except one, are important postulates of the kinetic-molecular theory of gases. Which one? a. Gases consist of large numbers of particles in rapid random motion. b. The volume of the molecules of a gas is very small compared to the total volume in which the gas is contained. c. The average kinetic energy of the molecules is inversely proportional to the absolute temperature. d. The time during which a collision between two molecules occurs is negligibly short compared to the time between collisions. e. There are no attractive or repulsive forces between the individual molecules. ANS: C OBJ: Identify the postulates of the kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 166. Which one of the following statements is not consistent with the kinetic-molecular theory? a. The volume occupied by the molecules (only) of a gas becomes significant only at very low pressures. b. A given sample of a gas is mostly empty space except near the liquefaction point. c. Except near the liquefaction point, the attractive forces between molecules of a gas are very small. d. Collisions between the molecules of a gas are elastic. e. The attractive forces between the molecules of a gas become significant only at very low temperatures. ANS: A OBJ: Understand the limits and applications of kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 167. Which statement is false? a. The molecules of an ideal gas are relatively very far apart on the average. b. The molecules of a gas move in unchanging curved paths until they collide with other molecules or the walls of their containers, according to the kinetic-molecular theory. c. The average kinetic energies of molecules of samples of different ideal gases at the same temperature are the same. d. The average kinetic energies of molecules of samples of different ideal gases at different temperatures are different. e. At a given temperature, according to the kinetic molecular theory, the average velocity of HF molecules is greater than the average velocity of F2 molecules. ANS: B OBJ: Understand the limits and applications of kinetic-molecular theory. TOP: The Kinetic-Molecular Theory
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168. Which of the following statements is false? An increase in temperature will a. increase the molecular weight of the gas. b. increase the velocity of the gas molecules. c. increase the number of collisions per second. d. increase the average kinetic energy of the molecules. e. increase the root-mean-square velocity of the molecules. ANS: A OBJ: Apply kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 169. Which one of the following statements does not describe ideal gases? a. The average kinetic energies of molecules of different kinds of gases are the same at a given temperature. b. Under ordinary conditions of temperature and pressure, gas molecules are widely separated. c. Gas molecules move in rapid, random, straight-line paths until collision occurs with other molecules or with the walls of the container. d. The volume occupied by the gas molecules themselves under ordinary conditions is large in comparison to the total volume occupied by the gas. e. Gases are "less ideal" near their liquefaction points. ANS: D OBJ: Apply kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 170. A gaseous mixture contains equal numbers of HCl and HBr molecules and no other kind of molecules. Which one of the following statements is true? Assume ideal gas behavior for both HCl and HBr. a. The masses of HCl and HBr are equal. b. The partial pressures of HCl and HBr are equal. c. If the temperature is increased while the volume is held constant, the partial pressure of HBr will rise more rapidly than the partial pressure of HCl. d. Since HCl molecules are lighter, they have higher velocities, collide with each other and with the walls of the container more frequently, and therefore contribute more to the total pressure of the mixture than do HBr molecules. e. None of these statements is true. ANS: B OBJ: Apply kinetic-molecular theory. TOP: The Kinetic-Molecular Theory 171. Which of the following gases would have the highest average molecular kinetic energy at 100C? a. H2 b. N2 c. CO2 d. He e. Ar ANS: A OBJ: Identify the gas with the highest average kinetic energy. TOP: The Kinetic-Molecular Theory
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172. Calculate the root-mean-square speed of NO molecules in meters/second at 25C. a. 498 m/s b. 144 m/s c. 49.5 m/s d. 248 m/s e. none of these ANS: A OBJ: Identify the gas with the highest speed. TOP: The Kinetic-Molecular Theory 173. Which of the following statements best describes effusion? a. expansion of a gas when heated b. movement of a gas through a very small opening c. spontaneous mixing of gases d. increasing vapor pressure due to increased temperature e. pressure is proportional to moles of gas ANS: B OBJ: Define effusion. TOP: Diffusion and Effusion of Gases 174. A mixture of 0.75 mol H2(g) and 0.75 mol N2(g) is introduced into a 15.0-liter container having a pinhole leak at 30C. After a period of time which of the following is true? a. The partial pressure of H2 exceeds that of N2 in the container. b. The partial pressure of N2 exceeds that of H2 in the container. c. The partial pressures of the two gases remain equal. d. The partial pressures of both gases increase above their initial values. e. The partial pressures of the two gases remain unchanged. ANS: B OBJ: Compare the partial pressures of a mixture of gases with a pinhole leak. TOP: Diffusion and Effusion of Gases 175. What is the order of increasing rate of effusion for the following gases? Ar, CO2, He, N2 a. b. c. d. e.
N2 < Ar < CO2 < He Ar < CO2 < He < N2 Ar < He < CO2 < N2 CO2 < N2 < Ar < He CO2 < Ar < N2 < He
ANS: E OBJ: Arrange the molecules according increasing rates of effusion. TOP: Diffusion and Effusion of Gases 176. A mixture of Ar, CH4, H2, CO, and PCl5 is released in the back of a classroom. Which gas reaches the front of the classroom first? a. Ar b. CO c. H2 d. PCl5 e. CH4
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ANS: C OBJ: Identify the gas that diffuses fastest. TOP: Diffusion and Effusion of Gases 177. The most significant intermolecular forces of attraction between individual nonpolar atoms or molecules in the gas phase are ____ attractions. a. dispersion b. strong electrostatic c. covalent d. ionic e. strong dipole ANS: A OBJ: Identify the most significant intermolecular force responsible for attractions between nonpolar gas molecules. TOP: Deviations from Ideal Gas Behavior 178. Which of the following statements about the Ideal Gas Law and the van der Waals equation of state is false? a. The van der Waals equation of state is more descriptive for real gases. b. All gases behave the same way in the Ideal Gas Law. c. At a given T and V, one mole of Ne and CH4 have the same pressure according to the Ideal Gas Law. d. The van der Waals equation corrects for deviations in the value of "R". e. The van der Waals equation corrects for the volume of molecules. ANS: D OBJ: Apply and interpret the ideal gas law and van der Waals equation of state. TOP: Deviations from Ideal Gas Behavior 179. Which of the following situations would one expect the most real gas behavior? a. He at 100 atm b. NH3 at 5 atm c. CO at 25C d. He at 10C e. CO2 at 100 atm ANS: E OBJ: Identify the gas and pressure combination most likely to deviate from ideal gas behavior. TOP: Deviations from Ideal Gas Behavior 180. Which one of the statements below is false? a. A real gas behaves more nearly as an ideal gas at high temperatures and low pressures. b. In the van der Waals equation, the "a" factor corrects for attractive forces, and one would expect a larger value of "a" for HF than for He. c. The "b" factor in the van der Waals equation should be larger for He than for Cl2. d. Gases approach their liquefaction points as temperature decreases and as pressure increases. e. Both "a" and "b" of the van der Waals equation have values of zero for an ideal gas. ANS: C OBJ: Understand the limits of ideal gas behavior and the interpretation of the van der Waals equation. TOP: Deviations from Ideal Gas Behavior
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181. The van der Waals constant, a, in the relationship
is a factor that corrects
for a. deviations in the gas constant, R. b. the attractive forces between gas molecules. c. the tendency of the gas molecules to ionize. d. the average velocities of the gas molecules. e. the volume occupied by the gas molecules. ANS: B OBJ: Identify the correct description of a variable in the van der Waals equation. TOP: Deviations from Ideal Gas Behavior
182. The van der Waals constant, b, in the relationship
is a factor that corrects
for a. deviations in the gas constant, R. b. the attractive forces between gas molecules. c. the tendency of the gas molecules to ionize. d. the average velocities of the gas molecules. e. the volume occupied by the gas molecules. ANS: E OBJ: Identify the correct description of a variable in the van der Waals equation. TOP: Deviations from Ideal Gas Behavior 183. Which of the following gases is expected to have the largest value for its van der Waals constant "b"? a. Ne b. O2 c. H2 d. CO e. CO2 ANS: E OBJ: Identify the gas with the largest volume correction in the van der Waals equation. TOP: Deviations from Ideal Gas Behavior 184. Which of the following gases is expected to have the smallest value for its van der Waals constant "a"? a. H2 b. O2 c. N2 d. Cl2 e. F2 ANS: A OBJ: Identify the molecule with the smallest value of the variable "a" in the van der Waals equation. TOP: Deviations from Ideal Gas Behavior
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185. Which of the following gases is expected to have the smallest value for its van der Waals constant "b"? a. Ne b. O2 c. N2 d. Cl2 e. H2O ANS: A OBJ: Identify the molecule with the smallest value of the variable "b" in the van der Waals equation. TOP: Deviations from Ideal Gas Behavior 186. Given the following van der Waals constants "a", which gas would behave least like an ideal gas? a. 4.17 L2-atm/mol2 b. 1.39 L2-atm/mol2 c. 0.034 L2-atm/mol2 d. 0.244 L2-atm/mol2 e. 3.59 L2-atm/mol2 ANS: A OBJ: Identify the value consistent with the largest deviation from ideality. TOP: Deviations from Ideal Gas Behavior 187. Which gas would be expected to behave most ideally? a. F2 b. Ne c. PCl3 d. NH3 e. N2 ANS: B OBJ: Identify the gas which would behave most ideally. TOP: Deviations from Ideal Gas Behavior 188. Which of the following gases would be expected to have a behavior closest to that of an ideal gas under most conditions? a. He b. O2 c. NH3 d. Cl2 e. H2O ANS: A OBJ: Ideal the gas which would behave most ideally. TOP: Deviations from Ideal Gas Behavior 189. Calculate the pressure (in atm) exerted by 1.00 mole of acetylene at 125C in a 20.0-liter container. The van der Waals constants for acetylene are: a = 20.0 L2 atm/mol2, b = 0.100 L/mol. a. 0.485 b. 0.533 c. 1.59 d. 1.64 e. 1.86
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ANS: C DIF: Harder Question OBJ: Use the van der Waals equation to determine pressure. TOP: Deviations from Ideal Gas Behavior 190. Calculate the pressure of 1000. grams of ethylene gas (C2H4) in a 10.0 L container at 30.0C. Do not assume ideal gas behavior. a = 4.471 L2-atm/mol2, b = 0.05714 L/mol. a. 35.7 atm b. 168 atm c. 54.6 atm d. 68.0 atm e. 88.8 atm ANS: C DIF: Harder Question OBJ: Use the van der Waals equation to determine pressure. TOP: Deviations from Ideal Gas Behavior 191. Calculate the pressure (in atm) exerted by 1.00 mole of ammonia at 27C in a 10.00-liter container. The van der Waals constants for ammonia are: a = 4.00 L2 atm/mol2, b = 0.0400 L/mol. (a and b have been rounded off to simplify the problem.) a. 2.38 b. 2.43 c. 2.34 d. 2.46 e. 2.29 ANS: B DIF: Harder Question OBJ: Use the van der Waals equation to determine pressure. TOP: Deviations from Ideal Gas Behavior 192. It is possible to make a barometer using a liquid other than mercury. What would be the
height (in meters) of a column of sea water at a pressure of 0.590 atm, given that 0.590 atm is equal to a 0.448 m column of mercury and the densities of mercury and sea water are 13.5 g/cm3 and 1.02 g/cm3, respectively. a. b. c. d. e.
5.93 m 0.169 m 0.0339 m 0.457 m 2.19 m
ANS: A DIF: easy OBJ: Determine the column height of a barometer made from a substance other than mercury. TOP: Pressure
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193. A flexible vessel contains 37 L of gas where the pressure is 1.5 atm. What will the volume be
when the pressure is 0.81 atm, the temperature remaining constant? a. 0.015 L b. 20 L c. 37 L d. 0.062 L e. 69 L ANS: E DIF: easy OBJ: Apply Boyle's Law to determine the volume. TOP: Boyle's Law: The Volume-Pressure Relationship 194. A flexible vessel contains 61.00 L of gas at a pressure of 2.20 atm. Under conditions of
constant temperature and moles of gas, what is the pressure of the gas when the volume of the vessel is decreased by a factor of four? a. b. c. d. e.
8.80 atm 0.550 atm 0.114 atm 2.20 atm 0.440 atm
ANS: A DIF: easy OBJ: Apply Boyle's Law to determine the volume. TOP: Boyle's Law: The Volume-Pressure Relationship 195. A flexible container is charged with 51.00 L of gas at 368. Under conditions of constant
pressure and moles of gas, what is the volume of the gas when the temperature is tripled? a. b. c. d. e.
153 L 17.0 L 0.0588 L 51 L 0.850 L
ANS: A DIF: easy OBJ: Apply Charles's Law to determine temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 196. A flexible container is charged with a certain volume of gas at 74.4C. Under conditions of
constant pressure and moles of gas, how does the temperature of the gas change when the volume is doubled? a. b. c. d. e.
The temperature increases by a factor of two. The temperature decreases by a factor of three. The temperature decreases by a factor of four. The temperature decreases by a factor of two. The temperature remains the same.
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ANS: A DIF: moderate OBJ: Apply Charles's Law to determine the change in temperature. TOP: Charles's Law: The Volume-Temperature Relationship; The Absolute Temperature Scale 197. Which of the following samples has the fewest moles of gas? a. 1.00 L of CH4 at 10°C and 1.00 atm b. 1.00 L of Ar at STP c. 1.00 L of NH3 at STP d. 1.00 L of H2 at 0.0°C and 1.92 atm e. 1.00 L of HCl at 30°C and 1.00 atm ANS: E DIF: easy OBJ: Determine the gas sample with the fewest moles of gas. TOP: Summary of Gas Laws: The Ideal Gas Equation 198. A mixture consisting of 0.105 mol N2, 0.022 mol O2, 0.124 mol CH4, and an unknown amount
of CO2 occupies a volume of 9.60 L at 24°C and 1.08 atm pressure. How many moles of CO2 are there in this sample? a. 0.749 mol b. 0.174 mol c. 2.10 mol d. 5.01 mol e. 0.425 mol ANS: B DIF: difficult OBJ: Determine the moles of gas in a mixture of gases. TOP: Dalton's Law of Partial Pressures 199. A 1.00-L sample of a gas at STP has a mass of 1.43 g. The molar mass of the gas is a. 6.38 g/mol. b. 32.0 g/mol. c. 22.4 g/mol. d. 44.8 g/mol. e. 157 g/mol. ANS: B DIF: easy OBJ: Calculate the molar mass of a gas. TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 200. A 22.4 L high pressure reaction vessel is charged with 0.5860 mol of iron powder and 1.78
atm of oxygen gas at standard temperature. On heating, the iron and oxygen react according to the balanced reaction below. 4Fe(s) + 3O2(g) 2Fe2O3(s) After the reaction vessel is cooled, and assuming the reaction goes to completion, what pressure of oxygen remains?
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a. b. c. d. e.
1.34 atm 1.78 atm 1.00 atm 0.440 atm 0.293 atm
ANS: A DIF: easy OBJ: Calculate the pressure of unreacted gas. TOP: Mass-Volume Relationships in Reactions Involving Gases 201. A small amount wet of hydrogen gas (H2) can be prepared by the reaction of zinc with excess
hydrochloric acid and trapping the gas produced in an inverted tube initially filled with water. If the total pressure of the gas collected in the tube is 735 mmHg at 27C, what is the partial pressure of the hydrogen? The vapor pressure of water is 26.7 mmHg. a. b. c. d. e.
709 mmHg 762 mmHg 735 mmHg 31.6 mmHg 53.4 mmHg
ANS: A DIF: moderate OBJ: Calculate the amount of gas collected over water. TOP: Mass-Volume Relationships in Reactions Involving Gases 202. An automobile tire is inflated to a pressure of 31.4 psi. What is the pressure in torr?
Hint: 1 atm = 760 torr = 14.7 psi a. 0.0281 torr b. 0.607 torr c. 1.65 torr d. 1620 torr e. 351000 torr ANS: D OBJ: Convert between pressure units. TOP: Pressure 203. A student reads a barometer in the laboratory and finds that the prevailing atmospheric
pressure to be 747 mmHg. What is the pressure in kPa? a. 0.00970 kPa b. 0.0100 kPa c. 99.6 kPa d. 103 kPa e. 5600 kPa ANS: C OBJ: Convert between pressure units. TOP: Pressure
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204. You are holding four identical balloons each containing 10.0 g of a different gas. The balloon
containing which gas is the largest balloon? a. Ar b. CH4 c. CS2 d. H2S e. All balloons will have the same volume. ANS: C OBJ: Use moles of gas to identify the largest balloon. TOP: Summary of Gas Laws: The Ideal Gas Equation 205. A sample of oxygen gas at a pressure of 1.18 atm and a temperature of 24.6oC, occupies a
volume of 868 mL. If the gas is compressed at a constant temperature until its pressure is 1.38 atm, the volume of the gas sample will be ______. a. 102 mL b. 221 mL c. 304 mL d. 578 mL e. 742 mL ANS: D OBJ: Calculate the new volume of a gas. TOP: Boyle's Law: The Volume-Pressure Relationship o
206. A helium-filled weather balloon has a volume of 652 L at 18 C and 756 mm Hg. It is released
and rises to an altitude of 6.55 km, where the pressure is 398 mm Hg and the temperature is 22oC. The volume of the balloon at this altitude is _________. a. 1070 L b. 1220 L c. 1260 L d. 1440 L e. 1510 L ANS: A OBJ: Determine the volume of a balloon given initial and final conditions. TOP: Summary of Gas Laws: The Ideal Gas Equation o
207. A sample of xenon gas occupies a volume of 7.52 L at 53 C and 0.643 atm. If it is desired to
decrease the volume of the gas sample to 4.60 L, while decreasing its pressure to 0.466 atm, the temperature of the gas sample at the new volume and pressure must be ______. a. -128oC b. -204oC c. -63.4oC d. 0.0426oC e. 23.6oC ANS: A OBJ: Calculate the gas temperature given initial and final conditions. TOP: Summary of Gas Laws: The Ideal Gas Equation 208. A 9.70-g piece of solid CO2 (Molar Mass = 44.01 g/mol) is allowed to sublime in a balloon.
The final volume of the balloon is 1.00 L at 298 K. What is the pressure of the gas inside the balloon? a. 5.39 atm b. 2.37 102 atm c. 2.52 atm d. 0.186 atm e. none of these ANS: A OBJ: Determine the gas pressure given mass, volume and temperature. TOP: Summary of Gas Laws: The Ideal Gas Equation
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209. A neon gas sample occupies a volume of 3.62 L at 21.6oC and 0.875atm. If the pressure
remains constant, at what temperature will the volume of the gas be 3.45 L? a. 309 K b. 281 K c. 20.6 K d. 295 K e. 554 K ANS: B OBJ: Determine the gas volume given initial and final conditions. TOP: Summary of Gas Laws: The Ideal Gas Equation 210. A student inflates a balloon to a volume of 972 mL by filling it with argon gas at a pressure of
1.50atm and a temperature of 15.8oC. How many grams of argon gas are needed? a. 2.46g b. 2.81g c. 4.49g d. 6.15g e. 11.2g ANS: A OBJ: Determine the mass of gas required to achieve the stated conditions. TOP: Summary of Gas Laws: The Ideal Gas Equation 211. Which of the following would have a higher rate of effusion than C2H2? a. N2 b. O2 c. Cl2 d. CH4 e. CO2 ANS: D OBJ: Identify the gas with a higher rate of effusion. TOP: Diffusion and Effusion of Gases
Use the information below to answer the following questions: You are provided four identical 1.0-L flasks contain the gases He, Cl2, CH4, and NH3, each at 25°C and 1 atm pressure. 212. Which gas has the highest density? a. He b. Cl2 c. CH4 d. NH3 e. all gases will have the same density ANS: B OBJ: Identify the gas with the highest density. TOP: Comparison of Solids, Liquids, and Gases 213. If the flasks are opened simultaneously, which gas will travel the farthest? a. He b. Cl2 c. CH4 d. NH3 e. all gases will have the same average velocity ANS: A OBJ: Identify the gas that diffuses fastest. TOP: Diffusion and Effusion of Gases
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214. Which flask contains the greatest number of moles of gas? a. He b. Cl2 c. CH4 d. NH3 e. All flasks will have the same number of moles of gas ANS: E OBJ: Identify the gas with the greatest number of particles. TOP: Summary of Gas Laws: The Ideal Gas Equation 215. Which gas will have the greatest average kinetic energy? a. He b. Cl2 c. CH4 d. NH3 e. all gases will have the same kinetic energy ANS: E OBJ: Identify the gas particles with the greatest kinetic energy. TOP: Diffusion and Effusion of Gases 216. Given the equation:
2 KClO3(s) 2 KCl(s) + 3 O2(g) A 3.00-g sample of KClO3 (Molar Mass = 122.55 g/mol) is decomposed and the oxygen is collected at 24.0°C and 0.991 atm. What volume of oxygen gas will be collected, assuming 100% yield? a. 0.602 L b. 0.730 L c. 0.904 L d. 0.401 L e. 0.559 L ANS: C OBJ: Calculate the volume of gas produced under the given reaction conditions. TOP: Mass-Volume Relationships in Reactions Involving Gases 217. The stopcock connecting a 5 L bulb containing nitrogen gas at a pressure of 9 atm, and a 10 L
bulb containing helium gas at a pressure of 6 atm is opened and the gases are allowed to mix. Assuming that the temperature remains constant, the final pressure in the system is: a. 3 atm b. 4 atm c. 7 atm d. 12 atm e. 15 atm ANS: C OBJ: Determine the total pressure of a gas mixture. TOP: Dalton's Law of Partial Pressures 218. A mixture of gases consists of CH4 at a partial pressure of 143 mm Hg, N2 at a partial pressure
of 469 mm Hg, and O2 at a partial pressure of 563 mm Hg. Calculate the mole fraction of oxygen in this mixture. a. 20.1 b. 0.399 c. 0.479 d. 0.741 e. 0.359 ANS: C OBJ: Calculate the mole fraction of a component in a mixture. TOP: Dalton's Law of Partial Pressures
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219. What volume of carbon dioxide is produced when 189 L of butane (C4H10) react with excess
oxygen, according to the following reaction? (all gases are at the same temperature and pressure) 2 C4H10(g) + 13 O2(g) 8 CO2(g) + 10 H2O(g) a. 151 L b. 378 L c. 526 L d. 756 L e. 993 L ANS: D OBJ: Calculate the volume of gas produced under the given conditions. TOP: Mass-Volume Relationships in Reactions Involving Gases o
220. A mixture of krypton and argon gases, in a 8.65L flask at 22.0 C, contains 15.3g of krypton
and 15.6g of argon. What is the total pressure in the flask? a. 0.428atm b. 0.511atm c. 0.865atm d. 1.09atm
e. 1.60atm
ANS: E OBJ: Calculate the total pressure given the mass all components. TOP: Dalton's Law of Partial Pressures 221. A mixture of argon and carbon dioxide gases, at a total pressure of 942mmHg, contains 5.75g
of argon and 11.4g of carbon dioxide. What is the partial pressure of carbon dioxide in the mixture? a. 158 mmHg b. 165 mmHg c. 337mmHg d. 605 mmHg e. 631 mmHg ANS: D OBJ: Calculate the partial pressure given the mass of each component and total pressure. TOP: Dalton's Law of Partial Pressures 222. What can you say about the pressures of the gases in the boxes below, if both gas samples are
at the same temperature? Box A Box B
a. b. c. d.
the sample in Box A has the highest pressure the sample in Box B has the highest pressure both samples have the same pressure not enough information to tell which has the highest pressure
ANS: A OBJ: Determine the relative pressures given the number of particles. TOP: Avogadro's Law and the Standard Molar Volume
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CONCEPTUAL 1. Describe what happens differently (on a molecular level) when a force is applied to molecules in the gaseous, liquid, and solid state. OBJ: Describe the effect of pressure on each state of matter. TOP: The Kinetic-Molecular Theory | Comparison of Solids, Liquids, and Gases 2. Describe what happens on a molecular level inside a balloon as it inflates. OBJ: Apply kinetic-molecular theory to the inflation of a balloon. TOP: The Kinetic-Molecular Theory 3. Why is mercury used to construct a barometer instead of water? What would the barometric pressure at sea level be in mm H2O? OBJ: Compare and contrast a barometer which uses water and one that uses mercury. TOP: Pressure 4. What happens to the rate of molecular collisions as a gas is compressed? What about as it is compressed and cooled? OBJ: Describe the rate of molecular collisions as a function of pressure and temperature. TOP: The Kinetic-Molecular Theory 5. What would happen to the pressure in a flask containing ozone, O3, if all the molecules instantly dissociated into molecular oxygen, O2 and atomic oxygen, O? OBJ: Describe the relationship between the number of gas particles and pressure. TOP: Avogadro's Law and the Standard Molar Volume 6. A new gas is discovered and determined to have van der Waals constants a = 6.17 L2-atm/mol2 and b = 0.063 L/mol. How would you expect this gas to behave, more or less ideally than Ar? Would the pressure calculated in the van der Waals equation be greater or less than the ideal gas pressure? OBJ: Compare the real gas behavior of two gases. TOP: Deviations from Ideal Gas Behavior 7. Why do high pressures and low temperatures affect ideal gas behavior more than low pressures and high temperatures? DIF: Harder Question OBJ: Compare and contrast the effects of high and low temperatures and pressures with respect to ideal behavior of a gas. TOP: Deviations from Ideal Gas Behavior 8. SF6 is a gas at STP. Based on what you know about the speed of gas molecules discuss the relative speeds of He molecules vs. SF6. Also discuss how this might affect the speed of sound in these gases and the sound an air horn might make if "blown" with these gases instead of air. OBJ: Contrast the speed of two different gas particles and the effect of these variables on the speed of sound and the production of sound. TOP: The Kinetic-Molecular Theory Whitten 10e
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Chapter 13—Liquids and Solids MULTIPLE CHOICE 1. Which one of the following statements does not describe the general properties of liquids accurately? a. Liquids have characteristic volumes that do not change greatly with changes in temperature. (Assuming that the liquid is not vaporized.) b. Liquids have characteristic volumes that do not change greatly with changes in pressure. c. Liquids diffuse only very slowly when compared to solids. d. The liquid state is highly disordered compared to the solid state. e. Liquids have high densities compared to gases. ANS: C OBJ: Identify the properties of liquids. TOP: Kinetic-Molecular Description of Liquids and Solids 2. Identify which property liquids do not have in common with solids. a. rigid shape b. volumes do not change significantly with pressure c. hydrogen bonding forces can be significant d. practically incompressible e. volumes do not change significantly with temperature ANS: A OBJ: Identify the difference between a solid and liquid. TOP: Kinetic-Molecular Description of Liquids and Solids 3. Which one of the following statements does not describe the general properties of solids accurately? a. Solids have characteristic volumes that do not change greatly with changes in temperature. b. Solids have characteristic volumes that do not change greatly with changes in pressure. c. Solids diffuse only very slowly when compared to liquids and gases. d. Solids are not fluid. e. Most solids have high vapor pressures at room temperature. ANS: E OBJ: Identify the properties of solids. TOP: Kinetic-Molecular Description of Liquids and Solids 4. Which of the following interactions are the strongest? a. hydrogen bonding force b. ion-ion interactions c. permanent dipole force d. dispersion force e. London force ANS: B OBJ: Identify the strongest attractive force. TOP: Intermolecular Attractions and Phase Changes
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5. Which of the following interactions are the strongest? a. hydrogen bonding b. London forces c. covalent bonds d. ion-ion interactions e. dispersion forces ANS: C OBJ: Identify the strongest interaction. TOP: Intermolecular Attractions and Phase Changes 6. The boiling points of the halogens increase in the order F2 < Cl2 < Br2 < I2 due to the resulting increasing ____ interactions. a. ion-dipole b. hydrogen-bonding c. ion-ion d. dispersion forces e. permanent dipole-dipole ANS: D OBJ: Identify the attractive force responsible for increasing boiling points. TOP: Intermolecular Attractions and Phase Changes 7. For which of the following would permanent dipole-dipole interactions play an important role in determining physical properties in the liquid state? a. BF3 b. ClF c. BeCl2 d. F2 e. CCl4 ANS: B OBJ: Identify the polar molecule. TOP: Intermolecular Attractions and Phase Changes 8. For which of the following would dispersion forces be the most important factor in determining physical properties in the liquid state? a. H2O b. NaCl c. F2 d. HF e. NH4Cl ANS: C OBJ: Identify the nonpolar molecule. TOP: Intermolecular Attractions and Phase Changes 9. For which of the following would hydrogen bonding not be an important factor in determining physical properties in the liquid state? a. HBr b. H2O c. HF d. NH3 e. H2O2
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ANS: A OBJ: Identify the molecule in which hydrogen bonding is not considered important. TOP: Intermolecular Attractions and Phase Changes 10. Which of the following substances will have the strongest intermolecular forces? a. H2S b. NO c. CH3NH2 d. HCl e. Rn ANS: C OBJ: Identify the substance with the greatest intermolecular forces of attraction. TOP: Intermolecular Attractions and Phase Changes 11. Which response correctly identifies all the interactions that might affect the properties of BrI? a. dispersion force, ion-ion interaction b. hydrogen bonding force, dispersion force c. permanent dipole force d. permanent dipole force, dispersion force e. dispersion force ANS: D OBJ: Identify the forces of attraction that might effect the properties of a compound. TOP: Intermolecular Attractions and Phase Changes 12. Dispersion forces are the only significant factor affecting boiling point for all the following compounds except? a. Ar b. H2SO4 c. CF4 d. Br2 e. CH4 ANS: B OBJ: Identify the substance that is not limited to dispersion forces. TOP: Intermolecular Attractions and Phase Changes 13. Which response correctly identifies all the interactions that might affect the properties of BF3? a. dispersion force, ion-ion interaction b. hydrogen bonding force, dispersion force c. permanent dipole force d. permanent dipole force, dispersion force e. dispersion force ANS: E OBJ: Identify the forces of attraction that might effect the properties of a compound. TOP: Intermolecular Attractions and Phase Changes
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14. Which response includes all of the following compounds that exhibit hydrogen bonding and no other compounds? CH4, AsH3, CH3NH2, H2Te, HF a. b. c. d. e.
AsH3, H2Te CH3NH2, HF CH4, AsH3, H2Te AsH3, CH3NH2 HF, H2Te
ANS: B OBJ: Identify the compounds which exhibit hydrogen bonding. TOP: Intermolecular Attractions and Phase Changes 15. Which liquid would have the highest viscosity at room temperature? a. C8H17NH2 b. C7H14 c. C9H18 d. C5H12 e. CH3NH2 ANS: A OBJ: Identify the compound with the greatest viscosity. TOP: Viscosity 16. The term used to describe resistance to flow of a liquid is ____. a. surface tension b. capillary action c. viscosity d. vapor pressure e. vaporization ANS: C OBJ: Define viscosity. TOP: Viscosity 17. Which of the following does not correctly describe viscosity? a. Viscosity is the resistance to flow of a liquid. b. Viscosity can be measured with a viscometer. c. The greater the ability of a liquid to hydrogen bond, the higher the viscosity. d. The smaller the molecule, the higher the viscosity. e. All of these correctly describe viscosity. ANS: D OBJ: Identify the incorrect description of viscosity. TOP: Viscosity 18. The most stable situation for liquid surface molecules is one in which the surface area is minimal. For a given volume, what shape has the least possible surface area? a. spherical b. cubic c. elliptical d. parabolic e. none of these
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ANS: A OBJ: What volume has a minimum of surface area. TOP: Surface Tension 19. Which of these liquids would have the highest surface tension at 25C? a. Br2 b. H2O c. CCl4 d. C5H12 e. CH3OCH3 ANS: B OBJ: Identify the compound with the greatest surface tension. TOP: Surface Tension 20. Which statement is false? a. In the absence of a phase change, the viscosity of a liquid increases as temperature decreases. b. All other factors being equal, if adhesive forces are strong, capillary action is likely to occur less readily than if adhesive forces are weak. c. The shape of a meniscus depends on the difference between the strengths of cohesive forces and adhesive forces. d. Coating glass with a nonpolar polymer greatly reduces the adhesion of the water to the glass. e. Capillary action helps plant roots take up water. ANS: B OBJ: Understand the factors effecting adhesion, cohesion, and capillary action. TOP: Capillary Action 21. Capillary action is ____ a. resistance to flow. b. the rate of collisions for gas molecules. c. the energy required to overcome the attractive forces between molecule in the liquid state to form a gas. d. the force required to expand the surface of a liquid. e. the drawing of a liquid up the inside of a small-bore tube when adhesive forces exceed cohesive forces. ANS: E OBJ: Define capillary action. TOP: Capillary Action 22. Car wax works to repel water because ____. a. wax exerts a very low adhesive force for water. b. the cohesive forces in water are very low. c. of capillary action present. d. the water adheres well with the wax. e. none of these. ANS: A OBJ: Identify the explanation for the water repellant character of a compound. TOP: Capillary Action
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23. Which liquid would evaporate most quickly at room temperature? a. H2O, 18 g/mol b. Gasoline, C8H18, 114 g/mol c. Vegetable oil, 895 g/mol d. Mineral oil, C12H26, 170 g/mol e. Ethylene glycol, HOCH2CH2OH, 62 g/mol ANS: B OBJ: Identify the compound that evaporates quickest. TOP: Evaporation 24. All of the following are gases at room temperature and atmospheric pressure. Which one will liquefy most easily when pressurized at a certain temperature? a. H2 b. Ar c. SiH4 d. NH3 e. F2 ANS: D OBJ: Which compound will condense most easily. TOP: Evaporation 25. As we increase the temperature of a liquid, its properties change. Which of the following would not be an expected change in the properties of a typical liquid as we increase its temperature? a. decrease in viscosity b. decrease in density c. increase in surface tension d. increase in vapor pressure e. increase in tendency to evaporate ANS: C OBJ: Identify a property change inconsistent with an increase in temperature of a substance. TOP: Evaporation 26. Volatile liquids are described by all of the following except: a. Volatile liquids are easily vaporized. b. Volatile liquids have relatively high vapor pressures. c. Volatile liquids have strong cohesive forces. d. Volatile liquids have weak intermolecular forces. e. All of these describe volatile liquids. ANS: C OBJ: Identify the property inconsistent with a volatile substance. TOP: Vapor Pressure 27. Which one of the following statements does not describe the general properties of liquids accurately? a. In the liquid state the close spacing of molecules leads to large intermolecular forces that are strongly dependent on the nature of the molecules involved. b. Liquids are practically incompressible. c. As the temperature of a liquid is increased, the vapor pressure of the liquid decreases. d. The normal boiling point of a liquid is the temperature at which the vapor pressure of the liquid becomes equal to exactly 760 torr. e. Vapor pressures of liquids at a given temperature differ greatly, and these differences in vapor pressure are due to the nature of the molecules in different liquids. Whitten 10e
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ANS: C OBJ: Identify the incorrect description of a liquid. TOP: Vapor Pressure 28. Which technique listed below separates a mixture of liquids on the basis of their boiling points? a. distillation b. extraction c. filtration d. reflux e. none of these ANS: A OBJ: Define distillation. TOP: Boiling Points and Distillation 29. Which of the following boils at the highest temperature? a. C2H6 b. C3H8 c. C4H10 d. C5H12 e. C6H14 ANS: E OBJ: Identify the compound with the highest boiling point. TOP: Boiling Points and Distillation 30. Which one of the following boils at the lowest temperature? a. H2O b. H2S c. H2Se d. H2Te e. H2Po ANS: B OBJ: Identify the compound with the lowest boiling point. TOP: Boiling Points and Distillation 31. Which one of the following boils at the lowest temperature? a. KNO3 b. XeF4 c. Kr d. NH3 e. AsH3 ANS: C OBJ: Identify the compound with the lowest boiling point. TOP: Boiling Points and Distillation 32. Which of the following boils at the lowest temperature? a. CF4 b. HF c. HCl d. KI e. SiF4
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ANS: A OBJ: Identify the compound with the lowest boiling point. TOP: Boiling Points and Distillation 33. Which property is not affected by strength of intermolecular forces? a. viscosity b. boiling point c. density d. vapor pressure e. molar heat of vaporization ANS: C OBJ: Identify the property not affected by intermolecular forces. TOP: Heat Transfer Involving Liquids 34. Which one of the following would have the highest molar heat of vaporization? a. CH3NH2 b. CH4 c. C2H6 d. SiH4 e. H2S ANS: A OBJ: Identify the compound with the greater heat of vaporization. TOP: Heat Transfer Involving Liquids 35. On a relative basis, the weaker the intermolecular forces in a substance are, a. the larger is its heat of vaporization. b. the more it deviates from the ideal gas law. c. the greater is its vapor pressure at a particular temperature. d. the larger is its molar heat capacity as a liquid. e. the higher is its boiling point. ANS: C OBJ: Identify the property or law that correlates with weak intermolecular forces. TOP: Heat Transfer Involving Liquids 36. Calculate the amount of heat required to raise the temperature of 165 g of water from 12.0C to 88.0C. (Sp. heat of H2O = 4.18 J/gC) a. 52.4 kJ b. 1.93 J c. 60.7 kJ d. 1.46 kJ e. 15.6 J ANS: A OBJ: Calculate the heat given mass of substance and change in temperature. TOP: Heat Transfer Involving Liquids
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37. How much heat is released when 165 g of liquid benzene, C6H6 heat of C6H6 = 1.74 J/gC) a. 4.35 J b. 6.26 kJ c. 45.5 kJ d. 18.9 kJ e. 22.4 kJ
, cools from 78.0C to 12.0C? (Sp.
ANS: D OBJ: Calculate the heat given mass of substance and change in temperature. TOP: Heat Transfer Involving Liquids 38. How much heat is absorbed if 45 grams of sweat is evaporated from someone's skin? Hvap for water at body temperature is 2.41 kJ/g. a. 43,400 J b. 53.6 kJ c. 108.5 J d. 108,500 J e. 115,100 J ANS: D OBJ: Calculate the heat required to convert a liquid to a gas. TOP: Heat Transfer Involving Liquids 39. Calculate the amount of heat (in joules) required to convert 92.5 g of water at 25.0C to steam at 108.0C. (Sp. heat of H2O = 4.18 J/gC, Sp. heat of H2O(g) = 2.03 J/gC, heat of vap. of H2O = 2.260 kJ/g) a. 2.26 105 J b. 3.05 104 J c. 2.40 105 J d. 2.20 104 J e. 6.43 105 J ANS: C OBJ: Calculate the heat required to convert a liquid to a gas. TOP: Heat Transfer Involving Liquids 40. How much heat is released when 40.0 g of steam at 250.0C cools and condenses to water at 30.0C? (Sp. heat of H2O = 4.18 J/gC, Sp. heat of H2O(g) = 2.03 J/gC, heat of vap. of H2O = 2.260 kJ/g) a. 24.0 kJ b. 23.0 J c. 32.9 kJ d. 114 kJ e. 122 kJ ANS: D OBJ: Calculate the heat released on cooling a gas to a liquid. TOP: Heat Transfer Involving Liquids
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41. If 100. grams of liquid water at 100.C and 200. grams of water at 20.0C are mixed in an insulated container, what will the final temperature of the mixture be? (Sp. heat of H2O = 4.18 J/gC) a. 46.7C b. 60.0C c. 66.7C d. 73.3C e. 77.8C ANS: A OBJ: Calculate the final temperature of a mixture of cold and hot liquid. TOP: Heat Transfer Involving Liquids 42. If 10.0 g of steam at 110.0C is pumped into an insulated vessel containing 100. g of water at 20.0C, what will be the equilibrium temperature of the mixture? (Sp. heat of H2O = 4.18 J/gC, Sp. heat of H2O(g) = 2.03 J/gC, heat of vap. of H2O = 2.260 kJ/g) a. 86.8C b. 54.5C c. 58.4C d. 38.6C e. 76.9C ANS: E DIF: Harder Question OBJ: Calculate the final temperature of a mixture of cold and hot liquid. TOP: Heat Transfer Involving Liquids 43. Using the Clausius-Clapeyron equation determine the vapor pressure of water at 50.0C. The molar heat of vaporization of water is 40.7 kJ/mol.
a. b. c. d. e.
700 torr 450 torr 100 torr 80 torr 55 torr
ANS: C DIF: Harder Question OBJ: Apply the Clausius-Clapeyron equation to determine pressure. TOP: Heat Transfer Involving Liquids 44. Which substance would be expected to have the highest heat of vaporization? a. Cl2 b. CCl4 c. C2Cl4 d. CH3OCH3 e. CH2OHCH2OH ANS: E OBJ: Identify the substance with the highest heat of vaporization. TOP: Heat Transfer Involving Liquids
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45. The Hvap is related to the strength of intermolecular forces. Which of the following has the lowest Hvap? a. C3H8 b. C6H12 c. C3H7OH d. C3H7NH2 e. C8H18 ANS: A OBJ: Identify the substance with the lowest heat of vaporization. TOP: Heat Transfer Involving Liquids 46. Which response has the following substances arranged in order of increasing boiling point? Ar, NaClO3, H2O, H2Se a. b. c. d. e.
NaClO3 < H2O < H2Se < Ar NaClO3 < H2Se < H2O < Ar Ar < NaClO3 < H2Se < H2O Ar < H2O < H2Se < NaClO3 Ar < H2Se < H2O < NaClO3
ANS: E OBJ: Arrange the compounds in order of increasing boiling point. TOP: Heat Transfer Involving Liquids 47. The melting point of a solid is the same as the ____ of its liquid. a. boiling point b. freezing point c. sublimation point d. triple point e. critical point ANS: B OBJ: Understand that melting point and freezing point are identical. TOP: Melting Point 48. Changes in pressure have ____ effects on melting point; changes in pressure have ____ effects on boiling points. a. small; small b. small; large c. large; small d. large; large e. unknown; unknown ANS: B OBJ: Identify the effects of pressure on boiling point and melting point. TOP: Melting Point 49. The amount of energy associated with holding the individual particles (atoms, ions, or molecules) together in a crystal lattice is most directly related to ____. a. the specific heat of the solid b. the heat of fusion of the solid c. the specific heat of the liquid d. the density of the solid e. the heat of condensation of the liquid Whitten 10e
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ANS: B OBJ: Identify the physical property associated with a crystalline lattice. TOP: Heat Transfer Involving Solids 50. What is the heat of fusion of chromium (in kJ/mol) if 10.0 grams of solid chromium absorb 2.82 103 J of heat in melting at 2173 K, its melting point? a. 1.34 b. 6.86 c. 48.5 d. 14.7 e. 34.3 ANS: D OBJ: Determine the heat of fusion of a substance. TOP: Heat Transfer Involving Solids 51. Which of the following does not affect the amount of heat transferred in solids? a. The value of specific heat. b. The amount of mass. c. The nature of the solid. d. The rate the temperature change occurred. e. The size of the temperature change. ANS: D OBJ: Identify the factor that does not affect the quantity of heat transferred. TOP: Heat Transfer Involving Solids 52. What would be the final temperature of the system if 30.0 g of lead at 150.C is dropped into 10.0 g of water at 10.0C in an insulated container? (Sp. heat of H2O = 4.18 J/gC, Sp. heat of Pb(s) = 0.128 J/gC) a. 12.4C b. 16.8C c. 19.4C d. 21.7C e. 24.6C ANS: D OBJ: Calculate the final temperature of a mixture of cold liquid and hot metal. TOP: Heat Transfer Involving Solids 53. What is the specific heat of a metal if a ten gram sample at 40.2C is dropped into 100 grams of water at 25.4C and the temperature rises to 28.6C? (Sp. heat of H2O = 4.18 J/gC) a. 2.11 J/g C b. 0.085 J/g C c. 206 J/g C d. 1.92 J/g C e. 20.9 J/g C ANS: A OBJ: Determine the specific heat of a hot metal used to heat a liquid. TOP: Heat Transfer Involving Solids
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54. Calculate the amount of heat absorbed by 10.0 grams of ice at 15.0C in converting it to liquid water at 50.0C. (Sp. heat of H2O(s) = 2.09 J/gC, Sp. heat of H2O = 4.18 J/gC, heat of fusion of H2O(s) = 333 J/g) a. 5.73 103 J b. 6.76 102 J c. 1.70 102 J d. 2.83 103 J e. 3.29 103 J ANS: A OBJ: Calculate the heat required to covert a solid to a liquid. TOP: Heat Transfer Involving Solids 55. Calculate the amount of heat required to convert 10.0 grams of ice at 20.C to steam at 120.C. (Sp. heat of H2O(s) = 2.09 J/gC, Sp. heat of H2O = 4.18 J/gC, Sp heat of H2O(g) = 2.03 J/gC; heat of fus. of H2O(s) = 333 J/g, heat of vap. of H2O = 2260 J/g) a. 18.6 kJ b. 26.3 kJ c. 30.9 kJ d. 41.2 kJ e. 46.4 kJ ANS: C OBJ: Calculate the heat required to convert a liquid to a gas. TOP: Heat Transfer Involving Solids 56. If 10.0 g of ice at 10.0C is placed in 200. g of water at 80.0C in an insulated container, what will be the temperature of the system when equilibrium is established? (Sp. heat of H2O(s) = 2.09 J/gC, Sp. heat of H2O = 4.18 J/gC, heat of fus. of H2O(s) = 333 J/g) a. 76C b. 65C c. 27C d. 20C e. 72C ANS: E OBJ: Calculate the final temperature of a mixture of cold and hot liquid. TOP: Heat Transfer Involving Solids 57. A chemical reaction releases 58,500 J of heat into 150 g of water. Assuming no heat is lost to the surroundings, what is the temperature increase of the water? (Sp. heat of H2O = 4.18 J/gC) a. 36.1C b. 93.2C c. 20.2C d. 106.4C e. 0.03C ANS: B OBJ: Calculate the change in temperature of a substance. TOP: Heat Transfer Involving Solids
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58. What will be the final temperature of the liquid water resulting from the mixing of 10.0 grams of steam at 130.C with 40.0 g of ice at 10.0C? (Sp. heat of H2O(s) = 2.09 J/gC, Sp. heat of H2O = 4.18 J/gC, Sp. heat of H2O(g) = 2.03 J/gC; heat of fusion of H2O(s) = 333 J/g, heat of vap. of H2O = 2260 J/g) a. 80.4C b. 72.6C c. 54.3C d. 46.1C e. 63.3C ANS: E OBJ: Calculate the final temperature of a mixture of solid and gas. TOP: Heat Transfer Involving Solids 59. How much heat would be required to convert 234.3 g of solid benzene, C6H6(s), at 5.5C into benzene vapor, C6H6(g), at 100.0C? mp of C6H6(s) = 5.5C bp of C6H6 = 80.1C molar heat of fusion at 5.5C = 9.92 kJ/mol molar heat of vaporization at 80.1C = 30.8 kJ/mol molar heat capacity of C6H6 = 136 J/molC molar heat capacity of C6H6(g) = 81.6 J/molC a. b. c. d. e.
106 kJ 158 kJ 53 kJ 32 kJ 5049 kJ
ANS: B DIF: Harder Question OBJ: Calculate the heat required to covert a solid to a gas. TOP: Heat Transfer Involving Solids 60. Some solids can be converted directly to the vapor phase by heating. The process is called ____. a. fusion b. sublimation c. vaporization d. condensation e. distillation ANS: B OBJ: Define sublimation. TOP: Sublimation and the Vapor Pressure of Solids 61. Which of the following statements is false? a. Solids exhibit vapor pressures, just as liquids do. b. Solids with low vapor pressures sublime easily. c. Dry ice vaporizes at atmospheric pressure and room temperature without passing through the liquid state. d. Deposition occurs when a vapor solidifies without passing through the liquid state. e. Most solids have much lower vapor pressures than liquids do. Whitten 10e
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ANS: B OBJ: Identify the incorrect description of a solid. TOP: Sublimation and the Vapor Pressure of Solids 62. A sketch of the phase diagram (not to scale) of water is given below.
Which statement is false? a. Line AD is the sublimation curve solid and vapor are in equilibrium. b. Point A is the triple point solid, liquid, and vapor are at equilibrium. c. Line AC is the vapor pressure curve liquid and gas (vapor) are in equilibrium. d. Line AB is the melting curve solid and liquid are in equilibrium. e. The slope of line AB is negative showing that as the liquid is cooled, the molecules get closer and closer together as they solidify. ANS: E OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 63. A sketch of a phase diagram is given below.
Which statement about this diagram is not true? a. Increasing pressure at constant temperature can melt the solid. b. Increasing temperature at constant pressure can cause the solid to sublime. c. Increasing temperature at constant pressure can cause the liquid to vaporize. d. Increasing pressure at constant temperature can cause deposition of solid from gas. e. Increasing pressure at constant temperature can cause liquid to freeze. ANS: E OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T)
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64. A sketch of the phase diagram (not to scale) of water is given below.
Which statement concerning the path (broken line) is false? a. At point E the water is all solid (ice). b. If heat is added to the ice at point E, the temperature of the ice increases until line AB is reached, then the temperature remains constant until all of the ice is melted into liquid. c. Once all the ice has melted (at the intersection of the broken line and line AB) the temperature of the water increases as heat is added until point F is reached. d. If more heat is added upon reaching point F, the temperature will remain constant as the liquid water vaporizes. e. Another way to vaporize all of the liquid water at point F is to increase the pressure. ANS: E OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 65. Amorphous solids are characterized by all the following statements except: a. Amorphous solids have no well-defined, ordered structure. b. The intermolecular forces between their particles are constant throughout the solid. c. Some amorphous solids are able to flow, like liquids. d. Amorphous solids do not exhibit sharp melting points. e. Amorphous solids shatter irregularly. ANS: B OBJ: Identify the statement inconsistent with an amorphous solid. TOP: Amorphous Solids and Crystalline Solids 66. Which of the following is an amorphous solid? a. graphite b. sodium chloride c. glass d. quartz e. diamond ANS: C OBJ: Identify the amorphous solid. TOP: Amorphous Solids and Crystalline Solids 67. In a body-centered cubic lattice, how many atoms are contained in a unit cell? a. one b. two c. three d. four e. five
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ANS: B OBJ: Identify the number of atoms in a unit cell. TOP: Structures of Crystals 68. Which statement about crystal structure is false? a. Polymorphous substances have more than one crystal structure. b. Rhombic, triclinic and cubic are examples of crystal structures. c. In a cubic lattice, four other cells share an atom lying at the corner of the unit cell equally. d. Isomorphous substances have only one crystal structure. e. Amorphous substances have no organized crystal structure. ANS: C OBJ: Identify the incorrect description of crystal structures. TOP: Structures of Crystals 69. In a face-centered cubic lattice, how many atoms are contained in a unit cell? a. one b. two c. four d. five e. six ANS: C OBJ: Identify the number of atoms in a unit cell. TOP: Structures of Crystals 70. In any cubic lattice, an atom at the corner of a unit cell is shared equally by how many unit cells? a. one b. two c. eight d. four e. sixteen ANS: C OBJ: Identify the number of unit cells that share an atom at the corner of a unit cell. TOP: Structures of Crystals 71. In a face-centered cubic lattice, an atom laying in a face of a unit cell is shared equally by how many unit cells? a. one b. two c. eight d. four e. sixteen ANS: B OBJ: Identify the number of unit cells that share an atom on the face of a unit cell. TOP: Structures of Crystals 72. In a cubic lattice, an atom on the edge of a unit cell is shared equally by how many unit cells? a. one b. two c. eight d. four e. twelve Whitten 10e
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ANS: D OBJ: Identify the number of unit cells that share an atom on the edge of a unit cell. TOP: Structures of Crystals 73. A single substance that can crystallize in more than one arrangement is said to be ____. a. isomorphous b. amorphous c. primitive d. triclinic e. polymorphous ANS: E OBJ: Define polymorphous. TOP: Structures of Crystals 74. Which one of the following statements is not applicable to covalent solids? a. The units that occupy the lattice points are atoms. b. The binding forces in covalent solids are shared electrons. c. Covalent solids have low melting points. d. Covalent solids are very hard. e. Covalent solids do not conduct electric current well. ANS: C OBJ: Identify the incorrect description of covalent solids. TOP: Bonding in Solids 75. Which one of the following statements is not applicable to metallic solids? a. The units that occupy the lattice points are positive ions. b. The binding forces in metallic solids are shared electron pairs. c. The melting points of metallic solids vary over a large range. d. The hardness of metallic solids varies from quite soft to quite hard. e. Metallic solids conduct electric current well. ANS: B OBJ: Identify the incorrect description of metallic solids. TOP: Bonding in Solids 76. Which one of the following statements is not applicable to molecular solids? a. The units that occupy the lattice points are molecules. b. The binding forces in molecular solids are dispersion forces or dispersion forces and dipole-dipole interactions. c. Molecular solids have relatively low melting points. d. Molecular solids are usually excellent conductors of electric current. e. Molecular solids are soft compared to covalent solids. ANS: D OBJ: Identify the incorrect description of molecular solids. TOP: Bonding in Solids 77. Which one of the following statements is not applicable to ionic solids? a. The units that occupy the lattice points are ions. b. The binding forces in ionic solids are electrostatic attractions. c. Most ionic solids are hard and brittle. d. Ionic solids are usually excellent conductors of electric current. e. Ionic solids have fairly high melting points. Whitten 10e
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ANS: D OBJ: Identify the incorrect description of ionic solids. TOP: Bonding in Solids 78. Which one of the following is not a general property of ionic solids? a. hard and brittle b. good electrical conductors in the solid state c. relatively high melting points d. strongest interparticle attractions are electrostatic e. positions of ions define the unit cell (lattice) ANS: B OBJ: Identify the incorrect property of an ionic solid. TOP: Bonding in Solids 79. Which statement is false? a. The size of an ion in a crystal is influenced by its environment, that is, by the other ions surrounding it. b. About 26% of the total volume of any cubic close packed crystal lattice is empty space. c. Two solids that crystallize in the same kind of crystal lattice are said to be isomorphous. d. An example of an amorphous solid is graphite. e. Elements and compounds can have more than one crystal structure. ANS: D OBJ: Identify an incorrect property or description of solids. TOP: Bonding in Solids 80. Which one of the following is a covalent solid? a. sulfur trioxide b. nickel c. ammonium chloride d. silicon carbide, SiC e. sucrose, C12H22O11 ANS: D OBJ: Identify the covalent solid. TOP: Bonding in Solids 81. Which one of the following is an ionic solid? a. graphite b. nickel c. ammonium chloride d. silicon carbide, SiC e. sucrose, C12H22O11 ANS: C OBJ: Identify the ionic solid. TOP: Bonding in Solids 82. Which one of the following is a metallic solid? a. graphite b. sulfur c. sodium d. silicon e. neon Whitten 10e
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ANS: C OBJ: Identify the metallic solid. TOP: Bonding in Solids 83. Which type of solid is expected for SO2? a. covalent b. ionic c. metallic d. molecular e. hypersaturated ANS: D OBJ: Match the type of solid with the substance. TOP: Bonding in Solids 84. Which type of solid is expected for Ga? a. covalent b. ionic c. metallic d. molecular e. intensive ANS: C OBJ: Match the type of solid with the substance. TOP: Bonding in Solids 85. Which one of the following is classified as a covalent solid? a. K2SO4 b. Cu c. Co d. C e. CH4 ANS: D OBJ: Identify the covalent solid. TOP: Bonding in Solids 86. Which one of the following is a molecular solid? a. NH4Cl b. K c. SiC d. C6H6 e. KC2H3O2 ANS: D OBJ: Identify the molecular solid. TOP: Bonding in Solids 87. Which one of the following crystallizes in a metallic lattice? a. C10H8 b. graphite c. In d. As e. KMnO4
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ANS: C OBJ: Identify the metal. TOP: Bonding in Solids 88. Which of the following, in the solid state, would be an example of a molecular crystal? a. diamond b. copper c. phosphorus trichloride d. magnesium fluoride e. sodium chloride ANS: C OBJ: Identify the molecular substance. TOP: Bonding in Solids 89. Which of the following in the solid state would be an example of a molecular crystal? a. carbon dioxide b. graphite c. cesium fluoride d. iron e. quartz ANS: A OBJ: Identify the molecular substance. TOP: Bonding in Solids 90. Which one of the following substances is incorrectly matched with the kind of solid it forms?
a. b. c. d. e.
Substance / Kind of Solid sulfur dioxide / molecular graphite / covalent calcium bromide / ionic potassium / ionic methane / molecular
ANS: D OBJ: Identify the incorrectly matched solid type and substance. TOP: Bonding in Solids 91. Which one of the following pairs is incorrectly matched?
a. b. c. d. e.
Substance / Classification H2O / molecular solid paraffin / molecular solid KF / ionic solid CsI / covalent solid Ni / metallic solid
ANS: D OBJ: Identify the incorrectly matched solid type and substance. TOP: Bonding in Solids
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92. Which one of the following pairs is incorrectly matched?
a. b. c. d. e.
Substance / Classification sand / covalent solid diamond / molecular solid Fe / metallic solid CaF2 / ionic solid quartz / covalent solid
ANS: B OBJ: Identify the incorrectly matched solid type and substance. TOP: Bonding in Solids 93. Which statement is false? a. Molecular solids generally have lower melting points than covalent solids. b. Metallic solids exhibit a wide range of melting points. c. The lattice of a metallic solid is defined by the position of the metal nuclei, and the valence electrons are distributed over the lattice as a whole. d. Most molecular solids melt at lower temperatures than metallic solids. e. The interactions among the molecules in molecular solids are generally stronger than those among the particles that define either covalent or ionic lattices. ANS: E OBJ: Identify the incorrect property or description of solids. TOP: Bonding in Solids 94. Substances have properties that are related to their structures. Which of the following statements regarding properties of solids is not expected to be correct? a. Solid potassium should be a good conductor of electricity. b. Solid CaSO4 should sublime readily. c. Molten LiCl should be a good conductor of electricity. d. Graphite should have a high melting point. e. Solid CO2 should have a low melting point. ANS: B OBJ: Identify the incorrect property or description of solids. TOP: Bonding in Solids 95. Substances have properties that are related to their structures. Which of the following statements regarding properties of solids is not expected to be correct? a. Molten KBr should be a good conductor of electricity. b. Diamond should have a high melting point. c. Solid sodium should be a good conductor of electricity. d. Solid CaF2 should have a low melting point. e. Silicon carbide, SiC, should not sublime readily. ANS: D OBJ: Identify the incorrect property or description of solids. TOP: Bonding in Solids
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96. Which one of the following melts at the lowest temperature at a given pressure? a. CH4 b. SiH4 c. NH3 d. SOCl2 e. H2O ANS: A OBJ: Identify the substance with the lowest melting point. TOP: Bonding in Solids 97. Which of the following compounds would be expected to have the highest melting point? a. BaF2 b. BaCl2 c. BaBr2 d. BaI2 e. NaF ANS: A OBJ: Identify the substance with the highest melting point. TOP: Bonding in Solids 98. Which of the following solid compounds has the highest melting point? a. Al2O3 b. MgF2 c. NaF d. CaF2 e. AlF3 ANS: A OBJ: Identify the substance with the highest melting point. TOP: Bonding in Solids 99. Arrange the following ionic compounds in order of increasing melting points. NaF, MgF2, AlF3, NaBr, NaI
a. b. c. d. e.
NaF < NaBr < NaI < MgF2 < AlF3 NaBr < NaI < NaF < AlF3 < MgF2 MgF2 < AlF3 < NaF < NaI < NaBr AlF3 < MgF2 < NaF < NaBr < NaI NaI < NaBr < NaF < MgF2 < AlF3
ANS: E OBJ: Arrange the compounds in order of melting points. TOP: Bonding in Solids
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100. Arrange the following in order of increasing melting points. CsCl, BaCl2, diamond (C), H2, HF
a. b. c. d. e.
H2 < HF < BaCl2 < CsCl < diamond HF < H2 < CsCl < BaCl2 < diamond H2 < HF < CsCl < BaCl2 < diamond H2 < HF < diamond < CsCl < BaCl2 HF < H2 < diamond < CsCl < BaCl2
ANS: C OBJ: Arrange the compounds in order of melting points. TOP: Bonding in Solids 101. Arrange the following in order of increasing melting points. KCl, He, H2O, HF
a. b. c. d. e.
He < H2O < HF < KCl H2O < HF < He < KCl KCl < H2O < HF < He He < HF < H2O < KCl H2O < He < KCl < HF
ANS: D OBJ: Arrange the compounds in order of melting points. TOP: Bonding in Solids 102. Which of the following solids could be described in this way: high melting point, hard solid, poor electrical conductor, non-electrolytic solution. a. NH3 b. Mg c. H2S d. MgCl2 e. SiO2 ANS: E OBJ: Match the substance with the description. TOP: Bonding in Solids 103. For crystal structures that contain only one kind of atom, the nearest neighbors of each atom can be visualized as lying along a line of the unit cell. For a simple cubic structure what is the orientation of that line with respect to the unit cell and how many atomic radii does it contain? a. cell edge and 2 atomic radii b. face diagonal and 4 atomic radii c. body diagonal and 3 atomic radii d. face diagonal and 2 atomic radii e. body diagonal and 4 atomic radii ANS: A OBJ: Identify the line of a unit cell. TOP: Bonding in Solids
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104. For crystal structures that contain only one kind of atom, the nearest neighbors of each atom can be visualized as lying along a line of the unit cell. For a body-centered cubic structure what is the orientation of that line with respect to the unit cell and how many atomic radii does it contain? a. cell edge and 2 atomic radii b. face diagonal and 4 atomic radii c. body diagonal and 3 atomic radii d. face diagonal and 2 atomic radii e. body diagonal and 4 atomic radii ANS: E OBJ: Identify the line of a unit cell. TOP: Bonding in Solids 105. In ideal close-packed structures of metallic solids, how many nearest neighbors does a metal ion have? a. 4 b. 3 c. 6 d. 8 e. 12 ANS: E OBJ: Determine the number of nearest neighbors in a close packed structure. TOP: Bonding in Solids 106. What is the coordination number for each sphere (metal ion) in a body-centered cubic structure? a. 4 b. 3 c. 6 d. 8 e. 12 ANS: D OBJ: Determine the coordination number in a bcc lattice. TOP: Bonding in Solids 107. Metallic calcium crystallized in a face-centered cubic lattice and the atomic radius of calcium is 1.97Å. Calculate the edge length, a, of a unit cell of calcium. a. 4.19Å b. 5.57Å c. 6.05Å d. 6.24Å e. 6.83Å ANS: B OBJ: Calculate the unit cell edge length given lattice type and atomic radius. TOP: Bonding in Solids 108. Metallic calcium crystallized in a face-centered cubic lattice, and the atomic radius of calcium is 1.97Å. Calculate the density of calcium. a. 1.28 g/cm3 b. 1.42 g/cm3 c. 1.54 g/cm3 d. 1.84 g/cm3 e. 2.11 g/cm3
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ANS: C DIF: Harder Question OBJ: Calculate the density given lattice type and atomic radius. TOP: Bonding in Solids 109. The density of palladium is 12.0 g/cm3. The unit cell of Pd is a face-centered cube. Calculate the atomic radius of Pd. a. 1.26Å b. 1.37Å c. 1.44Å d. 1.56Å e. 1.64Å ANS: B DIF: Harder Question OBJ: Calculate the atomic radius given lattice type and density. TOP: Bonding in Solids 110. An unknown metal crystallized in the hexagonal closest-packed structure and has a density of 12.2 g/cm3. Its atomic radius is 1.34Å. There are 4 atoms per unit cell. What is the metal? a. Mg b. Ba c. Fe d. Ru e. Au ANS: D DIF: Harder Question OBJ: Identify the metal given lattice type, density, and atomic radius. TOP: Bonding in Solids 111. Consider the metallic bonding in lithium. The interaction of all the 2s orbitals of one mole of lithium atoms produces a band consisting of ____ mole(s) of molecular orbitals (2s and 2s). a. one-eighth b. one-fourth c. one-half d. one e. two ANS: D OBJ: Identify the number of orbitals in a band given moles of atoms. TOP: Band Theory of Metals 112. In the metallic bonding of Na, the conduction band consists of ____ molecular orbitals and the empty band consists of ____ molecular orbitals. a. 2s and *2s b. 3s and *3s c. *2s and 2s d. *3s and *3s e. *3s and 3s ANS: B OBJ: Identify the orbital character of the given bands. TOP: Band Theory of Metals Whitten 10e
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113. The conduction band of magnesium is thought to result from the combination of molecular orbitals resulting from overlap of ____ atomic orbitals. a. 3s and 3p b. 3s and 3d c. 3d and 4s d. 3p and 3d e. 3s and 4s ANS: A OBJ: Identify the orbital character of the band. TOP: Band Theory of Metals 114. Which one of the following elements is considered a semiconductor? a. Li b. Fe c. Cl d. Ni e. Si ANS: E OBJ: Identify the semiconductor. TOP: Band Theory of Metals 115. Which one of the following elements is considered an insulator? a. Fe b. Ga c. N d. Ge e. Si ANS: C OBJ: Identify the insulator. TOP: Band Theory of Metals 116. The electrical conductivity of a metal ____ with increasing temperature and that of a semiconductor ____ with increasing temperature. a. increases; increases b. increases; decreases c. decreases; increases d. decreases; decreases e. remains the same; increases or decreases ANS: C OBJ: Identify the effects of temperature on the conductivity of a metal and semiconductor. TOP: Band Theory of Metals 117. Elements that have their highest energy electrons in a filled band of molecular orbitals that is separated from the lowest empty band by an energy difference much too large for electrons to jump between bands are called ____. a. semiconductors b. metals c. conductors d. insulators e. isomorphs
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ANS: D OBJ: Define insulator. TOP: Band Theory of Metals 118. Which of the following involves a change in temperature during the phase transition? a. b. c. d. e.
deposition of carbon dioxide fusion of ethanol condensation of ammonia all of the above none of the above
ANS: E DIF: moderate OBJ: Identify the phase transition that involves a temperature change. TOP: Phase Transitions and Temperature Changes 119. How much heat is released at constant pressure if a 18.0-L tank containing 42.0 atm of
hydrogen sulfide gas condenses at its boiling point of -60.0oC? The enthalpy of vaporization of hydrogen sulfide is 18.7 kJ/mol at -60.0oC. (R = 0.0821 L • atm/(K • mol)) a. 1.22 102 J b. 2.87 106 J c. 4.33 102 J d. 1.87 104 J e. 8.08 105 J ANS: E DIF: moderate OBJ: Calculate the heat released in the condensation of a gas. TOP: Phase Transitions and Changes in Energy 120. Which of the following statements concerning the accompanying phase diagram is false?
a. b. c. d. e.
The solid is less dense than the liquid. Point C is the critical point of the substance. Point A is the triple point of the substance. The normal boiling point is below the triple point. The curve AD divides the solid region from the gas region.
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ANS: A DIF: moderate OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 121. Krypton (Kr) is able to be liquefied at low temperatures due to which intermolecular force? a. b. c. d. e.
ionic bonding covalent bonding hydrogen bonding dipole–dipole London dispersion
ANS: E DIF: easy OBJ: Identify the force of attraction responsible for condensation of a specified gas. TOP: Intermolecular Attractions and Phase Changes 122. The space-filling representation provided below is an example of a _____ unit cell, which
contains _____ atom(s).
a. b. c. d. e.
simple cubic, 1 atom body centered cubic, 2 atoms face centered cubic, 4 atoms simple cubic, 8 atoms body centered cubic, 3 atoms
ANS: A DIF: easy OBJ: Identify the pictured cubic unit cell and determine the number of atoms contained in a single cell. TOP: Structures of Crystals 123. The metal lead crystallizes in a face-centered cubic lattice with an edge length of 495.1 pm.
What is the density of lead? a. 0.709 g/cm3 b. 2.84 g/cm3 c. 1.42 g/cm3 d. 5.67 g/cm3 e. 11.3 g/cm3
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ANS: E DIF: difficult OBJ: Calculate the density of a metal given the unit cell and edge length. TOP: Structures of Crystals 124. Strontium crystallizes in a face-centered cubic lattice. The density of the element is 2.63
g/cm3. What is the volume of a single unit cell? a. b. c. d. e.
2.21 10 22 cm3 1.53 10 21 cm3 2.88 10 26 cm3 5.53 10 23 cm3 3.83 10 22 cm3
ANS: A DIF: difficult OBJ: Calculate the volume of an fcc unit cell given the density. TOP: Structures of Crystals 125. Strontium crystallizes in a face-centered cubic lattice. The radius of strontium is 214 pm.
What is the edge length of the unit cell? a. b. c. d. e.
605 pm 428 pm 856 pm 454 pm 214 pm
ANS: A DIF: difficult OBJ: Calculate the fcc unit cell edge length of a pure metal given the metal radius. TOP: Structures of Crystals 126. The metal potassium crystallizes in a body-centered cubic lattice. If the radius of potassium is
227 pm, what is the unit cell edge length? a. b. c. d. e.
524 pm 454 pm 303 pm 227 pm 98.3 pm
ANS: A DIF: difficult OBJ: Calculate the bcc unit cell edge length of a pure metal given the metal radius. TOP: Structures of Crystals
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127. What is the simplest formula of the compound represented by the unit cell provided below?
a. b. c. d. e.
AB2 AB3 AB A2B4 A2B6
ANS: A DIF: difficult OBJ: Determine the formula of a substance given unit cell.
TOP: Structures of Crystals
128. What is the strongest type of interparticle force present in the solid H2S? a. Ion-ion c. Dipole-dipole b. Hydrogen-bonding d. Dispersion ANS: C OBJ: Identify the strongest interparticle force. TOP: Intermolecular Attractions and Phase Changes 129. Which of the following compounds would have the highest boiling point? a. KCl b. CH3OCH3 c. CH3CH2CH3 d. CH3CH2NH2 e. C12H22O11 ANS: A OBJ: Identify the compound with the highest boiling point. TOP: Boiling Points and Distillation 130. Which of the following statements is correct? a. KCl will have a higher vapor pressure at 25oC than HF b. NH3 will have a higher boiling point than BeO c. NH3 will have a lower vapor pressure at -50oC than NO d. N2 will have a higher boiling point than NO e. CH3CH2CH3 will have a lower vapor pressure at -50oC than CH3OCH3 ANS: C OBJ: Identify the correct statement about vapor pressure or boiling point. TOP: Boiling Points and Distillation | Vapor Pressure
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131. Which of the following compounds has a boiling point closest to that of argon? a. F2 b. Cl2 c. HCl d. NaF e. HF ANS: A OBJ: Identify the substances with similar boiling points. TOP: Boiling Points and Distillation 132. How much energy is given off when 55.0g of steam at 115.0oC is cooled to water at 75.0oC?
(csteam = 2.0 J/goC cwater = 4.18 J/goC cice = 2.03 J/goC) (Hvap = 40.7 kJ/mol Hfus = 6.02 kJ/mol) a. 7.52 kJ b. 25.8 kJ c. 116.8 kJ d. 131.6 kJ
e. 4400 kJ
ANS: D OBJ: Calculate the energy change that accompanies the phase change. TOP: Phase Transitions and Changes in Energy 133. At 10.0oC, the vapor pressure of nitric acid is 26.6 mmHg, and at 50.0oC, the vapor pressure is
208 mmHg. Using this information, calculate the heat of vaporization (Hvap) of nitric acid. a. 25.6 kJ/mol b. 39.1 kJ/mol c. 48.4 kJ/mol d. 225 kJ/mol e. 566 kJ/mol ANS: B OBJ: Use the vapor pressure data to determine the heat of vaporization. TOP: Vapor Pressure
Use the picture below to answer the following questions:
134. Which of the compounds above has the strongest intermolecular forces? a. Carbon disulfide, CS2 b. Methanol, CH3OH c. Ethanol, CH3CH2OH d. Heptane, CH3CH2CH2CH2CH2CH2CH3 e. Cannot tell from the information provided ANS: D OBJ: Use vapor pressure curves to identify the molecule with the strongest interparticle force. TOP: Intermolecular Attractions and Phase Changes
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135. What is the normal boiling point of methanol? a. 50oC b. 55oC c. 60oC
d. 65oC
e. 70oC
ANS: D OBJ: Use a vapor pressure curve to determine the normal boiling point. TOP: Vapor Pressure
Use the figures below to answer the following questions:
N-ethylpropanamide
diethyl ether
ethyl methyl ketone
cyclopentane
136. Which of the above would you predict to have the highest vapor pressure? a. N-ethylpropanamide c. ethyl methyl ketone b. diethyl ether d. cyclopentane ANS: D OBJ: Identify the molecule with the highest vapor pressure given the Lewis structures. TOP: Vapor Pressure 137. Which of the above would you predict to have the highest surface tension? a. N-ethylpropanamide c. ethyl methyl ketone b. diethyl ether d. cyclopentane ANS: A OBJ: Identify the molecule with the highest surface tension given the Lewis structures. TOP: Surface Tension o
138. Choose the statement which best explains why the boiling point of ICl (97 C) is higher than o
the boiling point of Br2 (59 C): a. The molecular weight of ICl is 162.4, while that of Br2 is 159.8. b. London dispersion forces are much stronger for ICl than for Br2. c. ICl is an ionic compound, while Br2 is a molecular compound. d. ICl is polar, while Br2 is nonpolar. e. There is hydrogen bonding in ICl, but not in Br2. ANS: D OBJ: Identify why two compounds have different boiling points. TOP: Boiling Points and Distillation
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139. The vapor pressure of liquid iron is 400mmHg at 2890K. Assuming that its heat of
vaporization is 356 kJ/mol, calculate the vapor pressure of liquid iron at a temperature of 3110K. a. 400.4 mmHg b. 360.2 mmHg c. 1140.8 mmHg d. 444.2 mmHg e. 140.2 mmHg ANS: C OBJ: Calculate the vapor pressure at a specified temperature. TOP: Vapor Pressure 140. Calculate the amount of energy required to melt a 48.9g sample of cobalt at its normal melting
point. Boiling point = 3097oC
melting point = 1495oC specific heat solid = 0.418 J/goC a. 12.9 kJ b. 18.7 kJ
Hvap = 389 kJ/mol
Hfus = 15.5 kJ/mol specific heat liquid = 0.686 J/goC c. 20.5 kJ d. 323 kJ e. 759 kJ
ANS: A OBJ: Calculate the energy required to melt a material. TOP: Phase Transitions and Changes in Energy Refer to the diagram below for the following questions:
141. Identify the line segment on the diagram below where the specific heat of the solid is used to
calculate energy flow: a. line segment A – B b. line segment B – D c. line segment D – F d. line segment F – H e. line segment H – J ANS: A OBJ: Translate a temperature-heat energy diagram. TOP: Phase Transitions and Changes in Energy
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142. Identify the line segment on the diagram below where the enthalpy of vaporization is used to
calculate energy flow: a. line segment A – B b. line segment B – D c. line segment D – F d. line segment F – H e. line segment H – J ANS: D OBJ: Translate a temperature-heat energy diagram. TOP: Phase Transitions and Changes in Energy 143. Identify the line segment on the above diagram where the enthalpy of fusion is used to
calculate energy flow: a. line segment A – B b. line segment B – D c. line segment D – F d. line segment F – H e. line segment H – J ANS: B OBJ: Translate a temperature-heat energy diagram. TOP: Phase Transitions and Changes in Energy 144. Identify the line segment on the above diagram where the specific heat of the liquid is used to
calculate energy flow: a. line segment A – B b. line segment B – D c. line segment D – F d. line segment F – H e. line segment H – J ANS: C OBJ: Translate a temperature-heat energy diagram. TOP: Phase Transitions and Changes in Energy 145. Identify the line segment on the above diagram where the specific heat of the gas is used to
calculate energy flow: a. line segment A – B b. line segment B – D c. line segment D – F d. line segment F – H e. line segment H – J ANS: E OBJ: Translate a temperature-heat energy diagram. TOP: Phase Transitions and Changes in Energy
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146. What type of compound is depicted above?
(C = dark atoms, H = light atoms) a. Binary acid b. Binary ionic c. Covalent - molecular d. Covalent - network e. Ternary ionic ANS: C OBJ: Identify the type of solid. TOP: Bonding in Solids 147. The electron sea model explains ______. a. the chemical reactivity of most metals b. why most metals are solids at room temperature c. the thermal conductivity of metals by the easy flow of nuclei d. the electrical conductivity of metals by the easy flow of nuclei e. the electrical conductivity of metals by the easy flow of electrons ANS: E OBJ: Define the electron sea model. TOP: Band Theory of Metals 148. You have a white, crystalline solid which has a melting point of 800oC. It does not conduct
electricity in the solid phase, but it forms a conducting solution when dissolved in water. Which of the following is the most likely formula for this compound? a. Mg b. Si c. CCl4 d. AlCl3 e. C6H12O6 ANS: D OBJ: Match the substance with the physical properties. TOP: Bonding in Solids 149. You have a white, crystalline solid which melts at 88oC. It does not conduct electricity in the
solid phase, and when it dissolves in water it still does not conduct electricity. Which of the following is the most likely formula for this compound? a. Mg b. Si c. CCl4 d. AlCl3 e. C6H12O6 ANS: E OBJ: Match the substance with the physical properties. TOP: Bonding in Solids
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150. A certain compound is formed by directional covalent bonds with a large gap between the
filled and empty molecular orbitals. It has a melting point of 1800oC. What is the crystal structure? a. Ionic b. Metallic c. Molecular d. Network ANS: D OBJ: Classify a solid given its physical properties. TOP: Bonding in Solids 151. The metal niobium crystallizes in a body-centered cubic unit cell. When x-rays with a
wavelength of 0.8302Å are used, the second-order (n=2) Bragg reflection from a set of parallel planes in a niobium crystal is observed at an angle of If the distance between these planes corresponds to a unit cell length (d = a), calculate the edge length of the niobium unit cell. a. 0.209Å b. 0.915Å c. 1.65Å d. 3.30Å e. 1005Å ANS: D OBJ: Determine the unit cell edge length given the x-ray wavelength and the unit cell. TOP: Structures of Crystals 152. As iron is heated to 1181K, it adopts one type of cubic cell (A); then, as the temperature rises
to 1674K, it changes to another cubic cell (B). The iron is changing from a _______ unit cell to a _______unit cell.
(A) a. b. c. d. e.
(B) Body-centered cubic simple cubic Body-centered cubic face-centered cubic Face-centered cubic simple cubic Face-centered cubic body-centered cubic Simple cubic face-centered cubic
ANS: B OBJ: Identify the unit cells. TOP: Structures of Crystals
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153. Shown below is the unit cell for sodium chloride. The larger spheres represent the chloride
anions. How would you describe the crystal packing structure for the chloride anions?
a. simple cubic
b. body-centered cubic
c. face-centered cubic
ANS: C OBJ: Identify the unit cell. TOP: Structures of Crystals 154. When X-rays with λ = 193.7 pm are used, the second-order Bragg reflection from a set of
parallel planes in a rubidium crystal occurs at an angle θ = 29.37°. Calculate the distance between the planes in the crystal. a. 6.595 pm b. 62.00 pm c. 124.0 pm d. 197.5 pm e. 394.9 pm ANS: E OBJ: Use the x-ray data to determine the distance between crystal planes. TOP: Structures of Crystals 155. Both solid and liquid CCl4 are molecular in nature. Which of the following statements is
true? a. Liquid CCl4 is much more compressible and more highly ordered than solid CCl4. b. The liquid CCl4 molecules are attracted to one another by covalent bonds. c. Liquid CCl4 is a slightly disordered arrangement of molecules with somewhat restricted mobility. d. Liquid CCl4 is a state in which there is little effect contributed by intermolecular forces on the physical properties of CCl4. (The liquid CCl4 does not feel the effects of intermolecular forces). ANS: C OBJ: Identify the best description of a molecular solid. TOP: Bonding in Solids 156. An unknown white solid was found to have a melting point of 150oC. It is soluble in
water, but it is a poor conductor in aqueous solution. Which of the following substances is the most likely? a. C6H12O6 (glucose) b. KCl c. Rb d. C (diamond) e. Si ANS: A OBJ: Identify the substance that best fits the physical properties. TOP: Bonding in Solids
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157. An unknown substance was found to have a melting point of ~300oC and was not soluble
water. It is a good conductor in both the melt and solid states. Which of the following substances is the most likely? a. C6H12O6 (glucose) b. KCl c. Rb d. C (diamond) e. Si ANS: C OBJ: Identify the substance that best fits the physical properties. TOP: Bonding in Solids
Use the phase diagram (not to scale) below for nitrogen to answer the following questions:
158. What is the normal melting point for nitrogen? a. 63.1K b. 63.2K c. 77.4K
d. 126.0K
ANS: B OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 159. What is the densest phase for nitrogen? a. Solid b. Liquid
c. Gas
d. supercritical
fluid ANS: A OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 160. At what temperature and pressure do the three phases coexist in equilibrium? a. 0.127atm and 63.1K b. 0.127atm and 63.2K c. 1.00atm and 77.4K d. 1.00atm and 63.2K e. 33.5atm and 126.0K
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ANS: A OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 161. Which picture below depicts the physical state present at 70K and 1.00atm? a. b. c.
ANS: A OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T)
Refer to the following phase diagram (not to scale!) for fluorine:
162. The densest phase of F2 is a a. solid b. liquid
c. gas
ANS: A OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 163. What is the normal boiling point temperature of F2? a. 53.4 K b. 53.5 K c. 85.0 K
d. 144.1 K
ANS: C OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T) 164. At 0.50 atm and 60K, F2 is a: a. solid b. liquid
c. gas
ANS: B OBJ: Interpret the phase diagram. TOP: Phase Diagrams (P versus T)
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CONCEPTUAL 1. The density of ice is less than that of water, which is rare for a solid. Discuss some situations in life that would be different if this were not true. OBJ: Describe a world where solid water is denser than the liquid. TOP: Structures of Crystals | Density 2. The specific heat of ice is 2.09 J/gC while the specific heat of lead is 0.128 J/gC. Explain why an igloo made of snow would be warmer in Alaska than a shelter with walls of lead. OBJ: Explain the relationship between specific heat and heat transfer. TOP: Heat Transfer Involving Solids 3. Using a phase diagram, explain why the sublimation of ice is not possible at room temperature. OBJ: Explain why the sublimation of ice is not possible at room temperature. TOP: Phase Diagrams (P versus T) 4. A new compound is synthesized and it is determined to be a covalent solid. In general terms, give some of its expected properties. OBJ: List the general properties of a covalent solid. TOP: Bonding in Solids 5. Insulators have large gaps in energy between the filled molecular orbital band and the empty one. Give some reasons why this gap increases left to right and from bottom to top on the periodic table. OBJ: Explain the observed trends in insulator band gaps. TOP: Band Theory of Metals 6. How would daily life be different if most solids exerted vapor pressures as high as most liquids? OBJ: Describe a world in which solids had vapor pressures equivalent to liquids. TOP: Vapor Pressure
Chapter 14: Solutions MULTIPLE CHOICE 1. Which of the following is not considered to occur if metallic sodium is placed in water? a. Sodium would dissolve. b. Sodium would react. c. Hydrogen gas would be produced. d. If evaporated to dryness, solid sodium hydroxide would be obtained. e. An oxidation state change would occur. ANS: A OBJ: Identify an incorrect description of a mixture of sodium and water. TOP: Spontaneity of the Dissolution Process 2. The dissolution process is exothermic if the amount of energy released in bringing about ____ interactions exceeds the sum of the amounts of energy absorbed in overcoming ____ and ____ interactions. Whitten 10e
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a. b. c. d. e.
solute-solute; solvent-solvent; solvent-solute solvent-solvent; solute-solute; solvent-solute solvent-solute; solute-solute; crystal lattice solute-solute; crystal lattice; solvent-solvent solvent-solute; solute-solute; solvent-solvent
ANS: E OBJ: Identify the interactions that occur in the dissolution process. TOP: Spontaneity of The Dissolution Process 3. The change in energy accompanying the process below is the ____ of MX. M+(g) + X(g) MX(s) a. b. c. d. e.
heat of hydration heat of solution crystal lattice energy of MX heat of ionization heat of dissociation
ANS: C OBJ: Define lattice energy. TOP: Dissolution of Solids in Liquids 4. Consider the three statements below. Which numbered response contains all the statements that are true and no false statements? I. Hydration is a special case of solvation in which the solvent is water. II. The oxygen end of water molecules is attracted toward Ca2+ ions. III. The hydrogen end of water molecules is attracted toward Cl ions. a. b. c. d. e.
I II III I and II I, II, and III
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ANS: E OBJ: Identify the correct descriptions of solvent-solute interactions and hydration. TOP: Dissolution of Solids in Liquids 5. Which one of the following solutes is most likely to have low water solubility due to the dissolution process being highly endothermic? a. AlF3 b. RbF c. CaF2 d. AgCl e. FeCl2 ANS: A OBJ: Identify the compound with the lowest solubility. TOP: Dissolution of Solids in Liquids 6. Which one of the following statements is false? a. All ions are hydrated in aqueous solution. b. All cations are hydrated in aqueous solution. c. All anions are hydrated in aqueous solution. d. Hydration is generally highly endothermic for ionic compounds. e. The heats of hydration of cations increases as their charge-to-radius ratios increase. ANS: D OBJ: Identify the incorrect description of hydration. TOP: Dissolution of Solids in Liquids 7. Which of the following solutions would not be expected to exist? a. MgCl2 in CCl4 b. NaCl in water c. Pentane, C5H12, in CCl4 d. methanol, CH3OH, in water e. Vegetable oil in mineral oil ANS: A OBJ: Identify the solute-solvent combination that does not give a solution. TOP: Dissolution of Liquids in Liquids (Miscibility) 8. Which of the following compounds is not miscible with water? a. (CH3CH2)2NH b. CH3COOH c. CCl4 d. CH3CN e. HOCH2CH2OH ANS: C OBJ: Identify the substance not miscible with water. TOP: Dissolution of Liquids in Liquids (Miscibility) 9. Which of the following compounds is not miscible with CCl4, carbon tetrachloride? a. gasoline b. pentane, C5H12 c. H2O d. CH3CH2OCH2CH3 e. freon-12, CCl2F2 Whitten 10e
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ANS: C OBJ: Identify the substance not miscible with water. TOP: Dissolution of Liquids in Liquids (Miscibility) 10. Which of the following pairs are not miscible? a. pentane, C5H12, and hexane, C6H14 b. ethanol, CH3CH2OH, and water c. benzene, C6H6, and hexane, C6H14 d. hexane, C6H14, and water e. methanol, CH3OH, and water ANS: D OBJ: Identify the solute-solvent combination that does not give a solution. TOP: Dissolution of Liquids in Liquids (Miscibility) 11. Consider the following pairs of liquids. Which numbered response contains all the pairs that are miscible and none that are immiscible? I. benzene, C6H6, and hexane, C6H14 II. water, H2O, and methanol, CH3OH III. water, H2O, and hexane, C6H14 a. b. c. d. e.
I I and II II and III II I, II, and III
ANS: B OBJ: Identify the solute-solvent combinations that give a solution. TOP: Dissolution of Liquids in Liquids (Miscibility) 12. Select the most appropriate explanation of the following observation on solubility: "Hydrogen chloride, HCl, is very soluble in water." a. Water is a polar solvent, and it promotes the ionization of many polar molecules. b. Opposites attract, that is, polar solutes dissolve in non-polar solvents and vice-versa. c. Water promotes the dissociation of many ionic solids. d. Gases that interact only slightly with solvents dissolve freely. e. Relatively light molecules are generally more soluble in water than heavier molecules. ANS: A OBJ: Identify the best description of a dissolution process. TOP: Dissolution of Gases in Liquids 13. Which of the following terms is not generally used in describing the dissolution of solids and gases in liquids? a. miscibility b. saturation c. molality d. molarity e. % solute by mass ANS: A OBJ: Identify the term not applied to solids and gases. TOP: Dissolution of Gases in Liquids
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14. At 25C, 100 g of water will be saturated with 35.7 g of NaCl. Which word below describes the solution of 1.55 mol of NaCl dissolved in 250 mL of water? a. saturated b. unsaturated c. supersaturated d. metasaturated e. none of these apply ANS: C OBJ: Identify the saturation level of a solution. TOP: Rates of Dissolution and Saturation 15. All of the following statements apply to supersaturated solutions. Which one is false? a. Supersaturated solutions contain higher-than-saturated concentrations of solute. b. Supersaturated solutions are metastable. c. Supersaturated solutions produce crystals rapidly if disturbed. d. Crystals will precipitate from a supersaturated solution until the solution is saturated. e. Supersaturated solutions are created by reaching saturation, then heating the solution. ANS: E OBJ: Identify an incorrect description of supersaturation. TOP: Rates of Dissolution and Saturation 16. Which one of the following statements is false? a. The effects of lattice energies and hydration energies oppose each other in the dissolution of solids in liquids. b. The solvation process usually absorbs heat. c. Nonpolar solids do not dissolve appreciably in polar solvents. d. The solubility of a gas that does not react with the solvent decreases as temperature increases. e. The separation of solute particles from a crystal requires energy. ANS: B OBJ: Identify an incorrect description of the dissolution process. TOP: Effect of Temperature on Solubility 17. Consider the dissolution of KCl in water, an endothermic process. Which of the following is true? a. The solubility of KCl increases as temperature increases. b. The solubility of KCl does not depend on temperature. c. The solubility of KCl increases as temperature increases, but only if pressure also increases. d. The solubility of KCl increases if pressure increases. e. None of these is true. ANS: A OBJ: Identify the best description of a dissolution process. TOP: Effect of Temperature on Solubility 18. Which numbered response lists all of the following statements that are true, and no false statements? I. Many solids that dissolve in endothermic processes have solubilities that increase as temperature increases. II. The solubility in water of a gas that does not react with water increases as the partial pressure of that gas above the surface of the solution increases. III. Most gases that are reasonably soluble in water are polar or else they react with water or ionize in water. Whitten 10e
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a. b. c. d. e.
I II I and II II and III I, II, and III
ANS: E OBJ: Identify the correct descriptions of solid and gas solubility. TOP: Effect of Pressure on Solubility 19. Which of the following statements about gas solubility in liquids is false? a. Most gases that are soluble in water are polar or react with water. b. Gas, liquid dissolutions are always endothermic. c. Gases are more soluble under high pressure than under low pressure. d. Gas solubility decreases with increasing temperature. e. A carbonated beverage will go flat more slowly in the refrigerator. ANS: B OBJ: Identify the incorrect description of gas solubility. TOP: Effect of Pressure on Solubility 20. If the concentration of CO2 is 2.90 g of CO2 per 1.00 L of soft drink when bottled under 2.0 atm of CO2 pressure, what will be the concentration of the CO2 in the drink after it has been opened and left to come to equilibrium with the atmosphere which has a CO2 partial pressure of 3.0 104 atm? a. 2.2 103 g CO2/L b. 2.0 104 g CO2/L c. 1.0 104 g CO2/L d. 4.4 104 g CO2/L e. 4.6 102 g CO2/L ANS: D OBJ: Determine the concentration of a gas in a solution given partial pressure of the gas above the liquid. TOP: Effect of Pressure on Solubility 21. Which one of the following statements is false? a. Carbon tetrachloride, CCl4, is more miscible with hexane, C6H14, than it is with a polar solvent like methanol, CH3OH. b. Gases are generally more soluble in water under high pressures than under low pressures. c. The solubilities of solids in liquids may either increase or decrease as temperature increases. d. Apparent percentage ionization of a polar covalent solute in water increases as concentration of the solute increases. e. A supersaturated solution can be described as being metastable. ANS: D OBJ: Identify an incorrect description of solubility and solutions. TOP: Effect of Pressure on Solubility
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22. The molality of a solution is a. the mass of solute divided by the kilograms of solvent. b. the moles of solute divided by the liters of solvent. c. the moles of solute divided by the kilograms of solvent. d. the mass of solute divided by the moles of solution. e. the moles of solute divided by the liters of solution. ANS: C OBJ: Define molality. TOP: Molality and Mole Fraction 23. Calculate the molality of a solution that contains 25 g of H2SO4 dissolved in 40. g of H2O. a. 3.2 m b. 4.4 m c. 6.4 m d. 13 m e. 14 m ANS: C OBJ: Calculate the molality of a solution given mass of solute and solvent. TOP: Molality and Mole Fraction 24. Calculate the molality of a solution prepared by dissolving 112. grams of copper (II) sulfate in 450. mL of water at 25C. a. 1.56 m b. 1.97 m c. 0.00197 m d. 3.92 m e. 1.86 m ANS: A OBJ: Calculate the molality of a solution given mass of solute and volume of solvent. TOP: Molality and Mole Fraction 25. What is the molality of an aqueous solution that is 10.0% ethanol, C2H5OH, by mass? a. 1.38 m b. 1.77 m c. 2.17 m d. 2.42 m e. 2.66 m ANS: D OBJ: Convert % mass to molality. TOP: Molality and Mole Fraction 26. Calculate the molality of a 10.0% H3PO4 solution in water. a. 0.380 m b. 0.760 m c. 1.13 m d. 1.51 m e. 1.89 m ANS: C OBJ: Convert % mass to molality. TOP: Molality and Mole Fraction Whitten 10e
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27. How many grams of sucrose, C12H22O11, must be dissolved in 750. mL of water to prepare a 0.250 molal solution? a. 64.1 g b. 114 g c. 85.5 g d. 78.2 g e. 96.4 g ANS: A OBJ: Calculate the mass of solute given solvent volume and molality. TOP: Molality and Mole Fraction 28. What mass of water must be used to dissolve 20.0 grams of ethanol, C2H5OH, to prepare a 0.0500 molal solution of ethanol? a. 3.76 kg b. 4.00 kg c. 8.70 kg d. 6.35 kg e. 7.18 kg ANS: C OBJ: Calculate the mass of solvent given solvent mass and molality. TOP: Molality and Mole Fraction 29. What is the mass % solute of a 2.00 molal H2SO4 solution in water? a. 1.1 % b. 9.8 % c. 19.6 % d. 2.0 % e. 16.4 % ANS: E OBJ: Convert molality to % mass. TOP: Molality and Mole Fraction 30. Calculate the molality of a solution that contains 51.2 g of naphthalene, C10H8, in 500. mL of carbon tetrachloride. The density of CCl4 is 1.60 g/mL. a. 0.250 m b. 0.500 m c. 0.750 m d. 0.840 m e. 1.69 m ANS: B OBJ: Calculate the molality of a solution given mass of solute and volume of solvent. TOP: Molality and Mole Fraction 31. What is the molality of a solution prepared by dissolving 10.0 grams of methylamine, CH3NH2, in 50.0 mL of ethanol, C2H5OH? The specific gravity of ethanol is 0.789. a. 6.30 m b. 8.18 m c. 4.26 m d. 5.16 m e. 3.87 m
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ANS: B OBJ: Calculate the molality of a solution given mass of solute and volume of solvent. TOP: Molality and Mole Fraction 32. A solution contains 10.0 g pentane, C5H12, 10.0 g hexane, C6H14 and 10.0 g benzene, C6H6. What is the mole fraction of hexane? a. 0.303 b. 0.116 c. 0.333 d. 0.362 e. 0.335 ANS: A OBJ: Calculate the mole fraction of a component given the composition of the mixture. TOP: Molality and Mole Fraction 33. If the mole fraction of methanol in a solution (with only water) is 0.28, what is the mole fraction of the water? a. 0.28 b. 1.28 c. 0.62 d. 0.72 e. 0.36 ANS: D OBJ: Calculate the mole fraction of a component given the composition of the mixture. TOP: Molality and Mole Fraction 34. What is the mole fraction of ethanol, C2H5OH, in a solution of 47.5 g of C2H5OH in 850. g of water? a. 0.021 b. 0.18 c. 0.032 d. 0.98 e. 0.028 ANS: A OBJ: Calculate the mole fraction of a component given the composition of the mixture. TOP: Molality and Mole Fraction 35. If 8.32 grams of methanol, CH3OH, are dissolved in 10.3 grams of water, what is the mole fraction of methanol in the solution? a. 0.61 b. 0.31 c. 0.11 d. 0.43 e. 0.36 ANS: B OBJ: Calculate the mole fraction of a component given the composition of the mixture. TOP: Molality and Mole Fraction
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36. If 41.6 g of acetic acid, CH3COOH, are dissolved in 65.0 g of water, what is the mole fraction of acetic acid? a. 0.200 b. 0.275 c. 0.161 d. 0.192 e. 0.840 ANS: C OBJ: Calculate the mole fraction of a component given the composition of the mixture. TOP: Molality and Mole Fraction 37. Calculate the mole fraction of ethanol, C2H5OH, in a solution that contains 230. grams of C2H5OH and 312 grams of benzene, C6H6. a. 0.44 b. 0.56 c. 0.57 d. 1.8 e. 2.3 ANS: B OBJ: Calculate the mole fraction of a component given the composition of the mixture. TOP: Molality and Mole Fraction 38. What is the mole fraction of CH3OH in a 3.50 m aqueous solution of CH3OH? a. 0.0630 b. 0.0679 c. 0.650 d. 0.350 e. 0.0592 ANS: E OBJ: Calculate the mole fraction of solute given molality. TOP: Molality and Mole Fraction 39. If the mole fraction of CH3OH in a solution with only water is 0.0250, what is the molality of the CH3OH? a. 12.4 m b. 3.82 m c. 1.42 m d. 5.76 m e. 0.0256 m ANS: C DIF: Harder Question OBJ: Calculate molality given the mole fraction of solute. TOP: Molality and Mole Fraction 40. What is the mole fraction of ethanol, CH3CH2OH, in an aqueous solution that is 20.0% ethanol by mass? a. 0.150 b. 0.144 c. 0.0980 d. 0.0892 e. 0.208 Whitten 10e
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ANS: D OBJ: Calculate mole fraction of solute given the % mass. TOP: Molality and Mole Fraction 41. Which of the following is not a colligative property? a. osmotic pressure b. vapor pressure raising c. boiling point elevation d. freezing point depression e. All of these are colligative properties ANS: B OBJ: Identify the property that is not colligative. TOP: Colligative Properties of Solutions 42. Physical properties that depend on the ____ but not the ____ of solute particles in a given amount of solvent are called colligative properties. a. number; kind b. polarity; number c. number; polarity d. kind; number e. polarity; concentration ANS: A OBJ: Complete the definition of colligative properties. TOP: Colligative Properties of Solutions 43. Sucrose is a nonvolatile, nonionizing solute in water. Determine the vapor pressure lowering, at 27C, of a solution of 75.0 grams of sucrose, C12H22O11, dissolved in 180. g of water. The vapor pressure of pure water at 27C is 26.7 torr. Assume the solution is ideal. a. 0.585 torr b. 0.058 torr c. 0.571 torr d. 5.62 torr e. 0.548 torr ANS: C OBJ: Calculate the vapor pressure lowering of a solution. TOP: Lowering of Vapor Pressure and Raoult's Law 44. Which aqueous solution would have the lowest vapor pressure at 25C? a. 1 M NaCl b. 1 M K3PO4 c. 1 M sucrose, C12H10O11 d. 1 M MgCl2 e. 1 M glucose, C6H12O6 ANS: B OBJ: Identify the solution with the lowest vapor pressure. TOP: Lowering of Vapor Pressure and Raoult's Law
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45. Calculate the vapor pressure of a solution prepared by dissolving 70.0 g of naphthalene, C10H8 (a nonvolatile nonelectrolyte), in 220.0 g of benzene, C6H6, at 20C. Assume the solution is ideal. The vapor pressure of pure benzene is 74.6 torr at 20C. a. 62.5 torr b. 14.5 torr c. 40.8 torr d. 60.1 torr e. 12.1 torr ANS: A OBJ: Calculate the vapor pressure of a solution given mass of solute and solvent. TOP: Lowering of Vapor Pressure and Raoult's Law 46. A solution consists of 0.450 mole of pentane, C5H12, and 0.250 mole of cyclopentane, C5H10. What is the vapor pressure of pentane in this solution at 25C? The vapor pressure of the pure liquids at 25C are 451 torr for pentane and 321 torr for cyclopentane. Assume that the solution is an ideal solution. a. 80.2 torr b. 188 torr c. 203 torr d. 290 torr e. 306 torr ANS: D OBJ: Calculate the vapor pressure of a solution given moles of solute and solvent. TOP: Lowering of Vapor Pressure and Raoult's Law 47. What is the vapor pressure of a aqueous solution containing 10 %(by weight) ethylene glycol (62 g/mol) at 25C. PH2O = 24.3 torr at 25C. a. 25.1 torr b. 21.9 torr c. 23.5 torr d. 18.9 torr e. 0.761 torr ANS: C OBJ: Calculate the vapor pressure of a solution given percent solute. TOP: Lowering of Vapor Pressure and Raoult's Law 48. A solution is made by mixing 52.1 g of propyl chloride, C3H7Cl, and 38.4 g of propyl bromide, C3H7Br. What is the vapor pressure of propyl chloride in the solution at 25C? The vapor pressure of pure propyl chloride is 347 torr at 25C and that of pure propyl bromide is 133 torr at 25C. Assume that the solution is an ideal solution. a. 236 torr b. 128 torr c. 136 torr d. 147 torr e. 155 torr ANS: A OBJ: Calculate the vapor pressure of solution component given mass of solute and solvent. TOP: Lowering of Vapor Pressure and Raoult's Law
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49. At 25C a solution consists of 0.450 mole of pentane, C5H12, and 0.250 mole of cyclopentane, C5H10. What is the lowering of the vapor pressure of pentane in this solution? The vapor pressure of the pure liquids at 25C are 451 torr for pentane and 321 torr for cyclopentane. Assume that the solution is an ideal solution. a. 115 torr b. 138 torr c. 161 torr d. 187 torr e. 206 torr ANS: C OBJ: Calculate the vapor pressure lowering of a solution given moles of each component. TOP: Lowering of Vapor Pressure and Raoult's Law 50. A solution is made by mixing 52.1 g of propyl chloride, C3H7Cl, and 38.4 g of propyl bromide, C3H7Br. What is the lowering of the vapor pressure of propyl chloride at 25C in this solution? The vapor pressure of pure propyl chloride is 347 torr at 25C and that of pure propyl bromide is 133 torr at 25C. Assume that the solution is an ideal solution. a. 192 torr b. 200 torr c. 111 torr d. 219 torr e. 171 torr ANS: C OBJ: Calculate the vapor pressure lowering of one component given mass of each component. TOP: Lowering of Vapor Pressure and Raoult's Law 51. At 40C, the vapor pressure of heptane is 92 torr. If a solution is made of naphthalene in heptane and has a vapor pressure of 82 torr, what is the mole fraction of naphthalene? Assume ideal solution behavior. a. 0.891 b. 0.435 c. 0.487 d. 0.109 e. 1.109 ANS: D OBJ: Calculate the mole fraction of solute given the vapor pressure of the solution. TOP: Lowering of Vapor Pressure and Raoult's Law 52. At 25C a solution consists of 0.450 mole of pentane, C5H12, and 0.250 mole of cyclopentane, C5H10. What is the mole fraction of cyclopentane in the vapor that is in equilibrium with this solution? The vapor pressure of the pure liquids at 25C are 451 torr for pentane and 321 torr for cyclopentane. Assume that the solution is an ideal solution. a. 0.284 b. 0.551 c. 0.716 d. 0.643 e. 0.357 ANS: A OBJ: Calculate the mole fraction of a component in the equilibrium vapor of a solution. TOP: Lowering of Vapor Pressure and Raoult's Law Whitten 10e
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53. Crude oil is a complex solution of liquids, and some gases and solids. The components are commonly separated from each other by utilizing a technique called fractional distillation. A physical property of the components upon which this technique is not dependent is ____. a. condensation point b. density c. volatility d. boiling point e. vapor pressure ANS: B OBJ: Identify the physical property not important in the process of distillation. TOP: Fractional Distillation 54. Which of the following compounds is not produced by fractional distillation of crude oil? a. heating oil b. diesel c. kerosene d. gasoline e. ethanol ANS: E OBJ: Identify the substance not produced by fractional distillation. TOP: Fractional Distillation 55. Which of these aqueous solutions would be expected to have the highest boiling point? a. 0.100 m KCl b. 0.100 m NaOH c. 0.075 m K2SO4 d. 0.050 m Al2(SO4)3 e. 0.200 m CH3OH ANS: C OBJ: Identify the solution with the highest boiling point. TOP: Boiling Point Elevation 56. If 4.27 grams of sucrose, C12H22O11, are dissolved in 15.2 grams of water, what will be the boiling point of the resulting solution? Kb for water = 0.512C/m. a. 101.64C b. 100.42C c. 99.626C d. 100.73C e. 101.42C ANS: B OBJ: Calculate the boiling point of a solution given mass of solute and solvent. TOP: Boiling Point Elevation
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57. The boiling point of pure water in Winter Park, CO ( elev. 9000 ft), is 94C. What is the boiling point of a solution containing 11.3 g of glucose (180 g/mol) in 55 mL of water in Winter Park? Kb for water = 0.512C/m. a. 94.6C b. 95.1C c. 98.6C d. 100C e. 93.4C ANS: A OBJ: Calculate the boiling point of a solution given mass of solute and volume of solvent. TOP: Boiling Point Elevation 58. Calculate the boiling point of a solution prepared by dissolving 70.0 g of naphthalene, C10H8 (a nonvolatile nonelectrolyte), in 220.0 g of benzene, C6H6. The Kb for benzene = 2.53C/m. The boiling point of pure benzene is 80.1C. a. 87.8C b. 73.8C c. 83.2C d. 86.4C e. 106.3C ANS: D OBJ: Calculate the boiling point of a solution given mass of solute and solvent. TOP: Boiling Point Elevation 59. Calculate the freezing point of a solution that contains 8.0 g of sucrose (C12H22O11) in 100. g of H2O. Kf for H2O = 1.86C/m. a. 0.044C b. 0.22C c. 0.39C d. 0.44C e. 0.04C ANS: D OBJ: Calculate the freezing point of a solution given mass of solute and solvent. TOP: Freezing Point Depression 60. Calculate the freezing point of a solution that contains 68.4 g of sucrose (table sugar) in 300. g of water. One mole of sucrose is 342 g. Kf for H2O = 1.86C/m. a. 0.186C b. 0.372C c. 0.558C d. 0.744C e. 1.24C ANS: E OBJ: Calculate the freezing point of a solution given mass of solute and solvent. TOP: Freezing Point Depression
Whitten 10e
Test Bank
500
61. Calculate the freezing point of a solution that contains 30.0 g of urea, CH4N2O, in 200. g of water. Urea is a nonvolatile nonelectrolyte. Kf for H2O = 1.86C/m. a. 1.86C b. 2.79C c. 3.72C d. 4.23C e. 4.65C ANS: E OBJ: Calculate the freezing point of a solution given mass of solute and solvent. TOP: Freezing Point Depression 62. Which of the following statements regarding a 1 M sucrose solution is not correct? a. The boiling point is greater than 100C. b. The freezing point is lower than that of a 1 M NaCl solution. c. The freezing point is less than 0.0C. d. The boiling point is lower than that of a 1 M NaCl solution. e. The vapor pressure at 100C is less than 760 torr. ANS: B OBJ: Identify the incorrect description of the properties of a solution. TOP: Freezing Point Depression 63. The freezing point of an aqueous solution containing 15 g of a nonelectrolyte in 150 mL water is 5.4C. What is the molecular weight of the compound? Kf = 1.86C/m for water. a. 121 g/mol b. 2.78 g/mol c. 34.4 g/mol d. 41.2 g/mol e. 53.8 g/mol ANS: C OBJ: Calculate the molecular weight of a solute using freezing point depression data. TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation 64. When 1.150 grams of an unknown nonelectrolyte dissolves in 10.0 grams of water, the solution freezes at 2.16C. What is the molecular weight of the unknown compound? Kf for water = 1.86C/m. a. 88.6 g/mol b. 116 g/mol c. 74.2 g/mol d. 99.1 g/mol e. 132 g/mol ANS: D OBJ: Calculate the molecular weight of a solute using freezing point depression data. TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation 65. A 4.305-gram sample of a nonelectrolyte is dissolved in 105 grams of water. The solution freezes at 1.23C. Calculate the molecular weight of the solute. Kf for water = 1.86C/m. a. 39.7 g/mol b. 58.4 g/mol c. 46.2 g/mol d. 62.0 g/mol e. 74.2 g/mol Whitten 10e
Test Bank
501
ANS: D OBJ: Calculate the molecular weight of a solute using freezing point depression data. TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation 66. When 20.0 grams of an unknown compound are dissolved in 500. grams of benzene, the freezing point of the resulting solution is 3.77C. The freezing point of pure benzene is 5.48C, and Kf for benzene is 5.12C/m. What is the molecular weight of the unknown? a. 120 g/mol b. 80.0 g/mol c. 100 g/mol d. 140 g/mol e. 160 g/mol ANS: A OBJ: Calculate the molecular weight of a solute using freezing point depression data. TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation 67. The freezing point of a solution of 1.048 g of an unknown nonelectrolyte dissolved in 36.21 g of benzene is 1.39C. Pure benzene freezes at 5.48C and its Kf value is 5.12C/m. What is the molecular weight of the compound? a. 59.2 g/mol b. 54.0 g/mol c. 61.4 g/mol d. 42.4 g/mol e. 36.3 g/mol ANS: E OBJ: Calculate the molecular weight of a solute using freezing point depression data. TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation 68. When 35.0 g of an unknown nonelectrolyte is dissolved in 220.0 g of benzene, the solution boils at 83.2C. Calculate the molecular weight of the unknown nonelectrolyte. The Kb for benzene = 2.53C/m. The boiling point of pure benzene is 80.1C. a. 130 g/mol b. 20.3 g/mol c. 183 g/mol d. 156 g/mol e. 194 g/mol ANS: A OBJ: Calculate the molecular weight of a solute using freezing point depression data. TOP: Determination of Molecular Weight by Freezing Point Depression or Boiling Point Elevation 69. A 0.1000 m aqueous solution of a weak acid, HA, is 1.5% ionized. At what temperature does it freeze? Kf for water = 1.86C/m. a. 0.0764C b. 0.189C c. 0.372C d. 0.564C e. 0.721C ANS: B OBJ: Calculate the freezing point of a solution given % ionization and molality of the solute. TOP: Colligative Properties and Dissociation of Electrolytes Whitten 10e
Test Bank
502
70. A 0.0490 molal aqueous NaBr solution freezes at 0.173C. What is its apparent percent dissociation in this solution? Kf = 1.86C/m for water. NaBr Na+ + Br a. b. c. d. e.
89.8% 84.2% 96.4% 77.0% 68.9%
ANS: A OBJ: Calculate the percent ionization given the solution molality and freezing point. TOP: Colligative Properties and Dissociation of Electrolytes 71. If the van't Hoff factor for NaCl is 1.88, what is the freezing point of a 0.50 molal NaCl solution in water? Kf = 1.86C/m for water. a. 0.93C b. 1.86C c. 1.75C d. 1.75C e. 1.86C ANS: C OBJ: Calculate the freezing point of a solution given molality. TOP: Colligative Properties and Dissociation of Electrolytes 72. The compound X2Y is only partially dissociated in water solution to form X+ and Y2 ions. A 0.0100 m solution is found to freeze at 0.040C. Calculate the apparent percent dissociation of X2Y. Kf for water = 1.86C/m. a. 42% b. 56% c. 58% d. 79% e. 85% ANS: C DIF: Harder Question OBJ: Calculate the percent ionization given the solution molality and freezing point. TOP: Colligative Properties and Dissociation of Electrolytes 73. Osmotic pressure ____. a. occurs only in ionic solutions. b. is lower with 1 M NaCl than 1 M sucrose. c. is created using detergents. d. is the hydrostatic pressure produced on the surface of a semi-permeable membrane by osmosis. e. is greater in the northern hemisphere than the southern hemisphere. ANS: D OBJ: Complete the definition of osmotic pressure. TOP: Osmotic Pressure
Whitten 10e
Test Bank
503
74. A 1.0 g sample of a molecular compound having a molecular weight of 100,000 g/mol is dissolved in 100. g of water. Calculate the osmotic pressure of the solution in torr at a temperature of 27C. (Assume the volume of the solution is 100. mL.) a. 1.9 torr b. 2.9 torr c. 3.9 torr d. 4.9 torr e. 5.9 torr ANS: A OBJ: Calculate the osmotic pressure of a solution. TOP: Osmotic Pressure 75. Calculate the osmotic pressure of a solution that contains 1.22 g of sucrose (C12H22O11) dissolved in 100. g of water at 25C. (Assume the volume of the solution is 100. mL.) a. 6.32 torr b. 108 torr c. 249 torr d. 497 torr e. 663 torr ANS: E OBJ: Calculate the osmotic pressure of a solution. TOP: Osmotic Pressure 76. Calculate the osmotic pressure associated with 50.0 g of an enzyme of molecular weight 98,000 g/mol dissolved in 2600. mL of benzene at 30.0C. a. 0.484 torr b. 1.68 torr c. 1.96 torr d. 2.48 torr e. 3.71 torr ANS: E OBJ: Calculate the osmotic pressure of a solution. TOP: Osmotic Pressure 77. Estimate the molecular weight of a biological macromolecule if a 0.100-gram sample dissolved in 50.0 mL of benzene has an osmotic pressure of 9.76 torr at 25.0C. a. 3.8 103 g/mol b. 4.2 104 g/mol c. 5.6 104 g/mol d. 6.7 104 g/mol e. 8.3 103 g/mol ANS: A OBJ: Calculate the molecular weight of a solute given the solution osmotic pressure. TOP: Osmotic Pressure
Whitten 10e
Test Bank
504
78. What is the molecular weight of a polymer if 1.55 g of it dissolved in 100 mL of water generates osmotic pressure equal to 15.2 torr at 25C? a. 24,100 g/mol b. 24.3 g/mol c. 624 g/mol d. 19.0 g/mol e. 19,000 g/mol ANS: E OBJ: Calculate the molecular weight of a solute given the solution osmotic pressure. TOP: Osmotic Pressure 79. Estimate the molecular weight of a polymer if a 100.-mL solution of 6.5 g of the polymer in toluene has an osmotic pressure of 0.044 atm at 27C. a. 62,000 b. 45,000 c. 22,000 d. 5500 e. 36,000 ANS: E OBJ: Calculate the molecular weight of a solute given the solution osmotic pressure. TOP: Osmotic Pressure 80. Colloids are described by all of the following except: a. The particles in a colloid are so small that settling is negligible. b. The mixture appears cloudy. c. Only combinations of liquids and gases can form colloids. d. Colloids are not suspensions or homogeneous mixtures. e. Mayonnaise, whipped cream and fog are all examples of colloids. ANS: C OBJ: Identify the statement that is inconsistent with the definition of a colloid. TOP: The Tyndall Effect 81. Which one of the following combinations must be a colloid?
a. b. c. d. e.
dispersed phase / dispersing medium solid / solid liquid / gas gas / gas gas / liquid liquid / liquid
ANS: B OBJ: Identify the colloid. TOP: The Tyndall Effect 82. Which one of the following is an example of an emulsion? a. shaving cream b. fog c. mayonnaise d. styrofoam e. white gold (an alloy)
Whitten 10e
Test Bank
505
ANS: C OBJ: Identify the emulsion. TOP: The Tyndall Effect 83. The Tyndall effect describes ____. a. precipitation of colloidal particles using electrically charged plates b. the adsorption of positive ions onto the surface of a hydrophilic solid c. hydrophobic interactions between nonpolar molecules d. the scattering of light by colloidal particles e. the bending of light by particles dissolved in solution ANS: D OBJ: Complete the definition of the Tyndall effect. TOP: The Tyndall Effect 84. The process of ____ involves adhesion of species onto the surface of colloid particles. a. adsorption b. absorption c. dispersion d. precipitation e. suspension ANS: A OBJ: Complete the definition. TOP: The Adsorption Phenomenon 85. The use of detergents containing ____ is now discouraged because they can cause eutrophication. a. phosphites b. sulfites c. nitrates d. phosphates e. sulfates ANS: D OBJ: Complete the statement about detergents. TOP: The Adsorption Phenomenon 86. All of the following describe detergents except: a. Detergents may contain sulfonate. b. Detergents do precipitate the ions of hard water. c. Detergents contain carboxylate groups. d. Detergents don't leave bathtub ring. e. Detergents can be used as soap substitutes. ANS: C OBJ: Identify the statement inconsistent with the description of detergents. TOP: The Adsorption Phenomenon 87. Which of the following statements about soaps and detergents is false? a. The polar end is attracted to grease and oil. b. They have a polar and a nonpolar end. c. They are emulsifiers for grease and oil. d. Phosphate detergents can produce pollution problems. e. They can be described as surfactants.
Whitten 10e
Test Bank
506
ANS: A OBJ: Identify the statement inconsistent with the definition of soaps and detergents. TOP: Hydrophilic and Hydrophobic Colloids 88. Which response contains only true statements about hydrophobic colloids? I. They cannot exist in water without an emulsifier. II. Milk and Mayonnaise are examples. III. Grease and oil are attracted to the hydrophilic end of soap molecules. a. b. c. d. e.
II, III I, II II III I, II, III
ANS: B OBJ: Identify the correct statements about hydrophobic colloids. TOP: Hydrophilic and Hydrophobic Colloids 89. Which one of the following statements about soaps and soap molecules is false? a. They have a polar end. b. They have a hydrophobic end. c. They are often sodium salts of long chain fatty acids. d. The hydrophilic end of a soap molecule is attracted by grease. e. They precipitate in water that contains Fe3+ ions. ANS: D OBJ: Identify the statement inconsistent with the definition of soaps. TOP: Hydrophilic and Hydrophobic Colloids 90. Which of the following is not a colligative property? a. boiling-point elevation b. osmotic pressure c. lattice energy d. freezing-point lowering e. vapor-pressure lowering ANS: C DIF: easy OBJ: Identify the non-colligative property. TOP: Colligative Properties of Solutions 91. What mass of a(n) 29.3% sucrose solution contains 62.8 g of water? a. 26.0 g b. 74.0 g c. 37.2 g d. 18.4 g e. 62.8 g ANS: A DIF: easy OBJ: Determine the mass of solute given the percent concentration and mass of water. TOP: Concentration units
Whitten 10e
Test Bank
507
92. What is the mass percent of an aqueous sodium hydroxide solution in which the mole fraction of NaOH is 0.231? The density of the solution is 1.4339 g/mL. a. 40.0% b. 6.21% c. 68.9% d. 33.1% e. 6.44% ANS: A DIF: difficult OBJ: Calculate the % mass solute given the mole fraction of solute. TOP: Concentration units 93. What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 25.0 m? The density of the solution is 1.5290 g/mL. a. 0.0612% b. 68.9% c. 1.76% d. 50.0% e. 0.654% ANS: D DIF: difficult OBJ: Calculate the percent mass solute given the molality and density. TOP: Concentration units 94. What is the vapor pressure at 20°C of an ideal solution prepared by the addition of 4.60 g of the nonvolatile solute urea, CO(NH2)2, to 50.2 g of methanol, CH3OH? The vapor pressure of pure methanol at 20°C is 89.0 mmHg. a. 4.15 mmHg b. 76.0 mmHg c. 81.5 mmHg d. 84.9 mmHg e. 13.0 mmHg ANS: D DIF: easy OBJ: Calculate the vapor pressure of a solution given the mass of solute and solvent. TOP: Lowering of Vapor Pressure and Raoult's Law 95. What is the freezing point of a 0.24 m solution of glucose, C6H12O6, in water? (Kf for water is 1.858°C/m.) a. 0.22°C b. 0.45°C c. –0.45°C d. –0.22°C e. –0.89°C ANS: C DIF: easy OBJ: Calculate the freezing point depression of a solution of nonelectrolyte given the molality. TOP: Freezing Point Depression
Whitten 10e
Test Bank
508
96. For a dilute solution of NH4NO3, the van’t Hoff factor (i) would be approximately a. 2. b. 3. c. 4. d. 1. e. 5. ANS: A DIF: easy OBJ: Estimate the van't Hoff factor of a compound. TOP: Colligative Properties and Dissociation of Electrolytes 97. Which of the following solutes in aqueous solution would be expected to exhibit the largest freezingpoint lowering (assuming ideal behavior)? a. 0.1 m MgCl2 b. 0.1 m CH3COH c. 0.05 m Al2(SO4)3 d. 0.1 m KCl e. 0.25 m NH3 ANS: A DIF: easy-moderate OBJ: Identify the solution which will give the lowest or highest freezing point depression. TOP: Colligative Properties and Dissociation of Electrolytes 98. Which of the following solutions has the lowest osmotic pressure? a. 0.10 M Al(NO3)3 b. 0.20 M NH3 c. 0.15 M Ba(NO2)2 d. 0.10 M MgCl2 e. 0.15 M NaCl ANS: B DIF: moderate OBJ: Identify the solution that will exhibit the lowest osmotic pressure. TOP: Colligative Properties and Dissociation of Electrolytes 99. Trimellitic acid is an organic acid that has a composition of 51.44% C, 2.88% H, and 45.68% O by mass. A 8.55-g sample of trimellitic acid dissolved in 20 g of acetone, CH3COCH3, has a boiling point of 59.68°C. What is the molecular formula of trimellitic acid? (Kb for acetone is 1.71°C/m, and pure acetone has a boiling point of 56.20°C.) a. CH2O b. C9H6O6 c. C3HO2 d. C18HO16 e. C6H2O4 ANS: B DIF: difficult OBJ: Determine the molecular formula of a compound given boiling point elevation data and percent composition. TOP: Boiling Point Elevation
Whitten 10e
Test Bank
509
100. Which of the following factors help determine whether or not a solution forms? a. The densities of the solute and solvent b. The polarities of the solute and solvent c. The energy of solvation (Hsolv) d. Two of the above e. All of the above ANS: D OBJ: Identify the factors that play a role in formation of a solution. TOP: Dissolution 101. When acetone is dissolved in water, the resulting solution becomes warm. Is this an endothermic or exothermic process? a. Endothermic b. Exothermic c. Cannot tell from the information provided ANS: B OBJ: Identify an exothermic dissolution process given qualitative observations. TOP: Dissolution 102. Which of the following correctly states the relationship between the solubility of a substance in water and the temperature of the solution? a. The solubility of a substance in water always increases as the temperature rises b. The solubility of a substance in water always decreases as the temperature rises c. The solubility of a solid substance in water cannot be accurately predicted as temperature rises d. The solubility of a gaseous substance in water decreases as the temperature decreases e. Two of the above are correct ANS: C OBJ: Identify the relationship between temperature and solubility. TOP: Effect of Temperature on Solubility 103. Which of the following liquids would you predict to be the most soluble in water? a. CCl4 b. CH3OH c. CH3(CH2)4OH d. CH3(CH2)4NH2 e. CH3(CH2)4CH3 ANS: B OBJ: Identify the most soluble compound given the condensed formula. TOP: Dissolution of Liquids in Liquids (Miscibility) 104. An aqueous solution is 22.0% by mass silver nitrate (AgNO3) and has a density of 1.22g/mL. What is the molality of this solution? a. 0.282m b. 1.06m c. 1.47m d. 1.66m e. 2.05m ANS: D OBJ: Calculate the molality given density and percent concentration. TOP: Molality and Mole Fraction
Whitten 10e
Test Bank
510
For the following questions describe the deviation of the solutions with respect to Raoult’s Law. 105. Hexane (C6H14) and octane (C8H18) a. Negative deviation b. Positive deviation
c. Ideal d. More information is needed
ANS: C OBJ: Describe the behavior of a mixture with respect to Raoult’s Law. TOP: Lowering of Vapor Pressure and Raoult's Law 106. Water (H2O) and chloroform (CHCl3) a. Negative deviation b. Positive deviation
c. Ideal d. More information is needed
ANS: B OBJ: Describe the behavior of a mixture with respect to Raoult’s Law. TOP: Lowering of Vapor Pressure and Raoult's Law 107. Which of the following would have the highest freezing point? a. 0.14m Na2CO3 b. 0.13m MnBr2 c. 0.11m ZnI2 d. 0.36m C6H12O6 e. Pure water ANS: E OBJ: Use molality to determine the solution with the highest freezing point. TOP: Freezing Point Depression 108. Select the one best completion to the statement: Boiling point elevation ______. a. occurs only for molecular solutes. b. occurs only when ionic solids are present. c. is the change in boiling point observed when one goes to a higher elevation. d. results from a reduction in the vapor pressure of the solution. e. occurs only at sea level. ANS: D OBJ: Define boiling point elevation. TOP: Boiling Point Elevation 109. How many grams of nickel(II) sulfate, NiSO4 (molar mass = 154.8g/mol) must be dissolved in
288.0g of water to raise the boiling point by 0.350oC? (Kb = 0.51oC.kg/mol) a. 10.19g b. 15.3 g c. 19.2 g d. 30.6 g e. 36.9 g ANS: B OBJ: Calculate the mass of solute require to achieve certain boiling point. TOP: Boiling Point Elevation
Whitten 10e
Test Bank
511
110. In a laboratory experiment, students synthesized a new compound and found that when 11.75g
of the compound was dissolved to make 256.2mL of an ethanol solution, the osmotic pressure generated was 4.12atm at 25oC. Assuming the compound is nonvolatile and a non-electrolyte, what is the molar mass of the compound? a. 178.7 g/mol b. 272.2 g/mol c. 326.2 g/mol d. 14,570 g/mol e. 27,580 g/mol ANS: B OBJ: Calculate the molar mass given osmotic pressure data. TOP: Osmotic Pressure 111. Calculate the heat of solution, ΔHsoln, if the lattice energy of the ionic solid is –155 kJ/mol and
the heat of hydration is -130. kJ/mol. a. -25 kJ/mol b. +25 kJ/mol c. -130 kJ/mol d. -285 kJ/mol e. +285 kJ/mol ANS: B OBJ: Calculate the heat of solution given the lattice energy and heat of hydration. TOP: Dissolution of Solids in Liquids 112. An aqueous solution is 36.0% by mass potassium bromide, KBr, and has a density of
1.33g/mL. Calculate the molality of the solution: a. 2.27m b. 3.03m c. 3.50m
d. 4.02m
e. 4.73m
ANS: E OBJ: Calculate the molality given the percent concentration and density. TOP: Molality and Mole Fraction
Whitten 10e
Test Bank
512
113. Which of the following would you predict to have the greatest solubility in water? a.
hexanol b.
propanol c.
pentane d.
ethyl methyl ketone e.
cyclobutane ANS: B OBJ: Predict the most soluble compound given the structural formula. TOP: Dissolution of Liquids in Liquids (Miscibility) 114. What would happen to the solubility of a gas in solution if the temperature is increased? a. solubility increases b. solubility decreases c. solubility remains the same d. it is impossible to predict what will happen to the solubility of a particular gas,
since solubility varies from substance to substance ANS: B OBJ: Describe the effect of temperature on gas solubility. TOP: Effect of Temperature on Solubility 115. What would happen to the solubility of a gas in solution if the pressure above the solution is
increased? a. solubility increases b. solubility decreases c. solubility remains the same d. it is impossible to predict what will happen to the solubility of a particular gas, since solubility varies from substance to substance ANS: A OBJ: Describe the effect of pressure on gas solubility. TOP: Effect of Pressure on Solubility
Whitten 10e
Test Bank
513
116. The vapor pressure of diethyl ether is 463.57 mmHg at 25oC. Calculate the vapor pressure of
the solution that forms when 10.33g of aspirin, C9H8O4 (Molar Mass = 180.1g/mol) is dissolved in 242.1 g of diethyl ether, C4H10O (Molar Mass = 74.12 g/mol). a. 80.00 mmHg b. 386.1 mmHg c. 420.0 mmHg d. 444.6 mmHg e. 455.6 mmHg ANS: E OBJ: Calculate the vapor pressure of a solution. TOP: Lowering of Vapor Pressure and Raoult's Law 117. The boiling point of ethanol, CH3CH2OH, is 78.500oC at 1atm. When 14.10g of an unknown,
non-electrolyte compound was dissolved in 282.0g of ethanol, the solution was found to have a boiling point of 78.833oC. What is the molar mass of the unknown compound? (Kb for ethanol = 1.22 oC.kg/mol) a. 68.65 g/mol b. 84.40 g/mol c. 145.68 g/mol d. 174.46 g/mol e. 183.18 g/mol ANS: E 118. Which of the following solutions would have the highest boiling point? a. 0.15m Zn(CH3COO)2 b. 0.16m BaI2 c. 0.10m Cr2(SO4)3 d. 0.35m CH4N2O e. pure water ANS: C OBJ: Use molality to determine the solution with the highest boiling point. TOP: Boiling Point Elevation 119. Which of the following solutions would have the highest freezing point? a. 0.15m Zn(CH3COO)2 b. 0.16m BaI2 c. 0.10m Cr2(SO4)3 d. 0.35m CH4N2O e. pure water ANS: E OBJ: Use molality to determine the solution with the highest freezing point. TOP: Freezing Point Depression
Whitten 10e
Test Bank
514
120. Which of the following solutions would have the highest osmotic pressure? a. 0.15m Zn(CH3COO)2 b. 0.16m BaI2 c. 0.10m Cr2(SO4)3 d. 0.35m CH4N2O e. pure water ANS: C OBJ: Use molality to determine the solution with the highest osmotic pressure. TOP: Osmotic Pressure CONCEPTUAL 1. Can a supersaturated solution exist for long periods of time? What are some factors that cause precipitation to occur in a supersaturated solution? OBJ: Explain supersaturation and list some ways to cause precipitation in a supersaturated solution. TOP: Dissolution of Solids in Liquids 2. Why are density and viscosity of a solution not considered colligative properties? OBJ: Explain why density and viscosity are not colligative properties. TOP: Colligative Properties of Solutions 3. In terms of the definition of boiling point, why can vapor-pressure lowering and boiling point elevation be considered the same phenomena? OBJ: Explain the relationship between vapor pressure and boiling point. TOP: Boiling Point Elevation | Lowering of Vapor Pressure and Raoult's Law 4. Explain why a larger solute particle, on an equal molar basis, will not give a different vapor-pressure lowering. OBJ: Explain the role of solute particle identity in vapor-pressure lowering. TOP: Lowering of Vapor Pressure and Raoult's Law 5. Describe the steps involved in reverse osmosis to produce a relatively pure sample of water. OBJ: Describe the process water purification by reverse osmosis. TOP: Osmotic Pressure 6. Many gases are only minimally soluble in water. Explain the relatively high solubility of each of the following gases in water: H2S (3.5 g/L), SO2 (106.4 g/L), and NH3 (520 g/L). OBJ: Explain the high aqueous solubility of certain gases. TOP: Dissolution of Gases in Liquids TRUE/FALSE 1. True or False? A mole of salt will lower the vapor pressure of water the same as a mole of
sugar. ANS: F Whitten 10e
Test Bank
515
Chapter 15—Chemical Thermodynamics MULTIPLE CHOICE 1. Which statement is incorrect? a. Energy is the capacity to do work or to transfer heat. b. Kinetic energy is the energy of motion. c. Potential energy is the energy that a system possesses by virtue of its position or composition. d. A process that absorbs energy from its surroundings is called exothermic. e. The Law of Conservation of Energy is another statement of the First Law of Thermodynamics. ANS: D OBJ: Identify the incorrect description of energy and the first law. TOP: The First Law of Thermodynamics 2. Which of the following statements about the first law of thermodynamics and energy is false? a. Kinetic energy can be converted to potential energy. b. Kinetic energy = 1/2 mv. c. All the energy in the universe is conserved. d. A system can never decrease its energy. e. Potential energy is the energy of position or composition. ANS: B OBJ: Identify the incorrect description of energy and the first law. TOP: The First Law of Thermodynamics 3. Which of the following statements is a correct interpretation of the First Law of Thermodynamics? a. The combined amount of matter and energy in the universe is a constant. b. Energy is neither created nor destroyed in chemical reactions. c. Energy is neither created nor destroyed in physical changes. d. All of these are correct. e. None of these are correct. ANS: D OBJ: Identify the correct interpretation of the first law. TOP: The First Law of Thermodynamics 4. Which one of the following thermodynamic quantities is not a state function? a. work b. enthalpy c. entropy d. internal energy e. free energy ANS: A DIF: Harder Question OBJ: Identify the quantity that is not a state function. TOP: Some Thermodynamic Terms
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516
5. Which term is not correctly matched? a. endothermic / energy is absorbed b. universe / system plus surroundings c. exothermic / energy is released d. thermodynamic state / conditions specifying the properties of a system e. state function / property dependent on how the process takes place ANS: E OBJ: Identify the incorrectly matched term and definition. TOP: Some Thermodynamic Terms 6. The enthalpy change, H, of a process is defined as: a. The maximum amount of useful work that can be done in a system. b. The increase or decrease in temperature in a system. c. The quantity of heat transferred in or out of a system as it undergoes a change at constant pressure. d. The change in molecular disorder in a system. e. None of these are correct. ANS: C OBJ: Define change in enthalpy. TOP: Enthalpy Changes 7. Which statement regarding enthalpy change is incorrect? a. H = Hfinal Hinitial b. Enthalpy change is a state function. c. H = qp d. The absolute enthalpy of a system can be experimentally measured. e. Hreaction = Hproducts Hreactants ANS: D OBJ: Identify the incorrect description of enthalpy or enthalpy change. TOP: Enthalpy Changes 8. An exothermic reaction liberates 7.58 kJ of heat in a coffee cup calorimeter containing 157 grams of solution. The temperature of the solution in the calorimeter increases by 11.2C. How much heat was absorbed by the calorimeter? Assume the specific heat of the solution is 4.184 J/gC. a. 223 J b. 7.36 kJ c. 657 J d. 5820 J e. 223 J ANS: A OBJ: Determine the amount of heat absorbed by the calorimeter. TOP: Calorimetry
Whitten 10e
Test Bank
517
9. If 4.168 kJ of heat is added to a calorimeter containing 75.40 g of water, the temperature of the water and the calorimeter increases from 24.58C to 35.82C. Calculate the heat capacity of the calorimeter (in J/C). The specific heat of water is 4.184 J/gC. a. 622 J/C b. 55.34 J/C c. 315.5 J/C d. 25.31 J/C e. 17.36 J/C ANS: B OBJ: Calculate the heat capacity of the calorimeter. TOP: Calorimetry 10. A 50.0 mL solution of 1.2 M HCl at 24.1C is mixed with 50.0 mL of 1.3 M NaOH, also at 24.1C, in a coffee-cup calorimeter. After the reaction occurs, the temperature of the resulting mixture is 29.8C. The density of the final solution is 1.05 g/mL. Calculate the molar heat of neutralization. Assume the specific heat of the solution is 4.184 J/gC. The heat capacity of the calorimeter is 32.5 J/C. a. 41.7 kJ/mol b. 58.5 kJ/mol c. 44.8 kJ/mol d. 13.0 kJ/mol e. 33.9 kJ/mol ANS: C OBJ: Calculate the molar heat of neutralization using calorimetry data. TOP: Calorimetry 11. A 51.6-mL dilute solution of acid at 23.85C is mixed with 48.5 mL of a dilute solution of base, also at 23.85C, in a coffee-cup calorimeter. After the reaction occurs, the temperature of the resulting mixture is 27.25C. The density of the final solution is 1.03 g/mL. Calculate the amount of heat evolved. Assume the specific heat of the solution is 4.184 J/gC. The heat capacity of the calorimeter is 23.9 J/C. a. 3.05 kJ b. 1.55 kJ c. 5.49 kJ d. 0.837 kJ e. 14.6 kJ ANS: B OBJ: Calculate the amount of heat evolved given calorimetry data. TOP: Calorimetry 12. How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction below? H0 for the reaction is +624.6 kJ. SiO2(g) + 3C(s) SiC(s) + 2CO(g) a. b. c. d. e.
366 kJ 1.13 105 kJ 5.06 kJ 1.33 104 kJ 31.2 kJ
Whitten 10e
Test Bank
518
ANS: E OBJ: Calculate the heat absorbed using the balanced thermochemical equation and mass of reactant. TOP: Thermochemical Equations 13. How much heat is released when 75 g of octane is burned completely if the enthalpy of combustion is 5,500 kJ/mol C8H18? C8H18 + 25/2 O2 8CO2 + 9H2O a. b. c. d. e.
7200 kJ 8360 kJ 4.1 105 kJ 3600 kJ 5500 kJ
ANS: D OBJ: Calculate the heat released using the balanced thermochemical equation and mass of reactant. TOP: Thermochemical Equations 14. The reaction of 5.5 grams of HCl with excess Ba(OH)2 releases 8300 J of heat. What is the molar heat of neutralization, H, for the reaction? a. 55 kJ/mol b. 55 kJ/mol c. 110 kJ/mol d. 27.5 kJ/mol e. 1500 J/mol ANS: B OBJ: Determine the balanced thermochemical equation given the reactants. | Calculate the molar heat of neutralization using the balanced thermochemical equation and mass of reactant. TOP: Thermochemical Equations 15. The burning of 80.3 g of SiH4 at constant pressure gives off 3790 kJ of heat. Calculate H for this reaction. SiH4(g) + 2O2(g) SiO2(s) + 2H2O a. b. c. d. e.
1520 kJ/mol rxn 47.2 kJ/mol rxn 4340 kJ/mol rxn 2430 kJ/mol rxn +4340 kJ/mol rxn
ANS: A OBJ: Calculate the heat released using the balanced thermochemical equation and mass of reactant. TOP: Thermochemical Equations
Whitten 10e
Test Bank
519
16. The "roasting" of 48.7 g of ZnS at constant pressure gives off 220. kJ of heat. Calculate the H for this reaction. 2ZnS(s) + 3O2(g) 2ZnO(s) + 2SO2(g) a. b. c. d. e.
110 kJ/mol rxn 293 kJ/mol rxn 440. kJ/mol rxn 881 kJ/mol rxn +440. kJ/mol rxn
ANS: D OBJ: Calculate the heat absorbed using the balanced thermochemical equation and mass of reactant. TOP: Thermochemical Equations 17. Which of the following statements is incorrect? a. The thermochemical standard state of a substance is its most stable state under one atmosphere pressure and at some specific temperature (298 K if not specified). b. A superscript zero, such as H0, indicates a specified temperature of 0C. c. For a pure substance in the liquid or solid phase, the standard state is the pure liquid or solid. d. For a pure gas, the standard state is the gas at a pressure of one atmosphere. e. For a substance in solution, the standard state refers to one-molar concentration. ANS: B OBJ: Identify the incorrect description or definition of the standard state of a substance. TOP: Standard States and Standard Enthalpy Changes 18. Which of the following substances is not in its standard state? a. C, graphite b. Br2, c. O3, (g) d. H2, (g) e. Hg, ANS: C OBJ: Identify the substance not in its standard state. TOP: Standard States and Standard Enthalpy Changes 19. For which of the following substances does a. CO2(g) b. H2O(g) c. Na(s) d. Br2(g) e. C(diamond)
?
ANS: C OBJ: Identify the substance with an enthalpy of formation of zero. TOP: Standard Molar Enthalpies of Formation, Delta H°f
Whitten 10e
Test Bank
520
20. Which of the following substances is not correctly matched with its molar heat of formation, a. C6H6 / = 49.03 kJ/mol b. SO2(g) / c. Br2(g) / d. H2O / e. Ca(s) /
?
= 296.8 kJ/mol =0 = 285.8 kJ/mol =0
ANS: C OBJ: Identify the substance with the incorrect enthalpy of formation. TOP: Standard Molar Enthalpies of Formation, Delta H°f 21. Calculate the amount of heat released in the complete combustion of 8.17 grams of Al to form Al2O3(s) at 25C and 1 atm. for Al2O3(s) = 1676 kJ/mol 4Al(s) + 3O2(g) 2Al2O3(s) a. b. c. d. e.
254 kJ 203 kJ 127 kJ 237 kJ 101 kJ
ANS: A OBJ: Calculate the heat released using the balanced chemical equation, product enthalpy of formation, and mass of reactant. TOP: Standard Molar Enthalpies of Formation, Delta H°f 22. How much heat energy is liberated when 11.0 grams of manganese is converted to Mn2O3 at standard state conditions? is 962.3 kJ/mol. a. b. c. d. e.
96.2 kJ 192 kJ 289 kJ 460 kJ 964 kJ
ANS: A OBJ: Calculate the heat released given the product enthalpy of formation and mass of reactant. TOP: Standard Molar Enthalpies of Formation, Delta H°f 23. When 32.1 g of H2 reacts with excess silicon to form SiH4(g) at standard conditions, 270.1 kJ of heat is absorbed. What is the for SiH4? a. 33.7 kJ/mol b. 67.3 kJ/mol c. 33.7 kJ/mol d. 8.41 kJ/mol e. 67.3 kJ/mol ANS: A OBJ: Calculate the product enthalpy of formation given mass of reactant and heat absorbed in the reaction. TOP: Standard Molar Enthalpies of Formation, Delta H°f Whitten 10e
Test Bank
521
24. Which of the following is not a formation reaction? a. 1/2H2(g) + 1/2Br2 HBr(g) b. H2(g) + 1/2O2(g) H2O c. Ca(s) + 1/2O2(g) CaO(s) d. 4Al(s) + 3/2O2(g) Al2O3(s) e. H2O + SO3 H2SO4 ANS: E OBJ: Identify the chemical equation that is not a formation reaction. TOP: Standard Molar Enthalpies of Formation, Delta H°f 25. From the following data at 25C, H2(g) + Cl2(g) 2HCl(g) 2H2(g) + O2(g) 2H2O(g)
H0 = 185 kJ H0 = 483.7 kJ
Calculate H0 at 25C for the reaction below. 4HCl(g) + O2(g) 2Cl2(g) + 2H2O(g) a. b. c. d. e.
+299 kJ 114 kJ 299 kJ +114 kJ 86.8 kJ
ANS: B OBJ: Calculate the enthalpy of a reaction using Hess's law. TOP: Hess's Law 26. Given the following at 25C and 1.00 atm: 1/2N2(g) + O2(g) NO2(g) N2(g) + 2O2(g) N2O4(g)
H0 = 33.2 kJ H0 = 11.1 kJ
Calculate the H0 for the reaction below at 25C. 2NO2(g) N2O4(g) a. b. c. d. e.
+11.0 kJ +44.3 kJ +55.3 kJ 22.1 kJ 55.3 kJ
ANS: E OBJ: Calculate the enthalpy of a reaction using Hess's law. TOP: Hess's Law 27. Given the enthalpy changes for the following reactions, calculate for CO(g). C (graphite) + O2(g) CO2(g) = 393.5 kJ CO(g) + 1/2O2 CO2(g)
Whitten 10e
H0 = 283.0 kJ
Test Bank
522
a. b. c. d. e.
6.78 102 kJ 6.78 102 kJ +110.5 kJ 110.5 kJ 173 kJ
ANS: D OBJ: Calculate the enthalpy of formation of a substance using Hess's law. TOP: Hess's Law 28. Given the standard heats of formation for the following compounds, calculate for the following reaction. CH4(g) + H2O(g) + H2(g) CH3OH 0 75 242 238 (kJ/mol) a. b. c. d. e.
+79 kJ 79 kJ +594 kcal 594 kcal 405 kJ
ANS: A OBJ: Calculate the enthalpy of a reaction given the balanced reaction and enthalpies of formation. TOP: Hess's Law 29. Calculate H0 at 25C for the reaction below. 2ZnS(s) + 3O2(g) 0 205.6 (kJ/mol) a. b. c. d. e.
2ZnO(s) 348.3
+ 2SO2(g) 296.8
257.1 kJ 879.0 kJ +257.1 kJ 582.2 kJ +879.0 kJ
ANS: B OBJ: Calculate the enthalpy of a reaction given the balanced reaction and enthalpies of formation. TOP: Hess's Law 30. Calculate H0 for the following reaction at 25.0C. Fe3O4(s) + CO(g) 1118 110.5 (kJ/mol) a. b. c. d. e.
3FeO(s) 272
+ CO2(g) 393.5
263 kJ 54 kJ 19 kJ 50 kJ 109 kJ
Whitten 10e
Test Bank
523
ANS: C OBJ: Calculate the enthalpy of a reaction given the balanced reaction and enthalpies of formation. TOP: Hess's Law 31. Calculate the standard enthalpy change for the reaction below. C(graphite) + 4HNO3 CO2(g) 0 174.1 393.5 (kJ/mol) a. b. c. d. e.
+ 4NO2(g) 33.2
+ 2H2O 285.8
123.9 kJ 472.1 kJ 201.9 kJ 404.8 kJ 135.9 kJ
ANS: E OBJ: Calculate the enthalpy of a reaction given the balanced reaction and enthalpies of formation. TOP: Hess's Law 32. Calculate the standard enthalpy change for the reaction below. 12NH3(g) + 21O2(g) 8HNO3 0 45.9 133.9 (kJ/mol) a. b. c. d. e.
+ 4NO(g) 91.3
+ 14H2O(g) 241.8
+3,540 kJ 4,650 kJ 2,259 kJ 4270 kJ 3,540 kJ
ANS: E OBJ: Calculate the enthalpy of a reaction given the balanced reaction and enthalpies of formation. TOP: Hess's Law 33. Evaluate H0 for the reaction below at 25C. SiO2(s) + 4HF(aq) 910.9 320.8 (kJ/mol) a. b. c. d. e.
SiF4(g) 1615
+ 2H2O 285.8
+293.3 kJ 954.9 kJ 366.5 kJ 7.5 kJ 1781.1 kJ
ANS: D OBJ: Calculate the enthalpy of a reaction given the balanced reaction and enthalpies of formation. TOP: Hess's Law 34. Use the data below to calculate for benzene, C6H6 , at 25C and 1 atm. 2C6H6 + 15O2(g) 12CO2(g) + 6H2O H0 = 6535 kJ = 393.5 kJ/mol, = 285.8 kJ/mol
Whitten 10e
Test Bank
524
a. b. c. d. e.
49.1 kJ/mol 3.51 104 kJ/mol 103 kJ/mol 1.76 103 kJ/mol 561 kJ/mol
ANS: A OBJ: Calculate the enthalpy of formation of a substance using Hess's law. TOP: Hess's Law 35. Given the following at 25C, calculate for HCN(g) at 25C. 2NH3(g) + 3O2(g) + 2CH4(g) 2HCN(g) + 6H2O(g)
= 870.8 kJ
= 80.3 kJ/mol for NH3(g), 74.6 kJ/mol for CH4, 241.8 kJ/mol for H2O(g). a. b. c. d. e.
135 kJ/mol 147 kJ/mol +270 kJ/mol 870.8 kJ/mol +135 kJ/mol
ANS: E OBJ: Calculate the enthalpy of formation of a substance using Hess's law. TOP: Hess's Law 36. Given that H0 for the oxidation of sucrose, C12H22O11(s), is 5648 kJ per mole of sucrose at 25C, evaluate for sucrose. C12H22O11(s) + 12O2(g) 12CO2(g) + 11H2O ? 0 393.5 285.8 (kJ/mol) a. b. c. d. e.
1676 kJ/mol 2218 kJ/mol 1431 kJ/mol 1067 kJ/mol 2640 kJ/mol
ANS: B OBJ: Calculate the missing enthalpy of formation given the balanced reaction. TOP: Hess's Law at 25C for CO(g), given that H0 at 25C for the reaction below is 809.9 kJ. 2CH4(g) + O2(g) + 4Cl2(g) 8HCl(g) + 2CO(g) 0 0 ? 74.81 92.31 (kJ/mol)
37. Calculate
a. b. c. d. e.
110.5 kJ/mol 177.5 kJ/mol 160.0 kJ/mol 437.7 kJ/mol 486.6 kJ/mol
Whitten 10e
Test Bank
525
ANS: A OBJ: Calculate the missing enthalpy of formation given the balanced reaction. TOP: Hess's Law 38. How much heat is evolved in the formation of 35.0 grams of Fe2O3(s) at 25C and 1.00 atm pressure by the following reaction? 4Fe(s) + 3O2(g) 2Fe2O3(s) 0 0 824.2 (kJ/mol) a. b. c. d. e.
90.4 kJ 180.7 kJ 151 kJ 360.1 kJ 243. 9 kJ
ANS: B OBJ: Calculate the heat released using the balanced reaction, heats of formation, and mass of product. TOP: Hess's Law 39. How much heat is released when 6.38 grams of Ag(s) reacts by the equation shown below at standard state conditions? 4Ag(s) + 2H2S(g) + O2(g) 2Ag2S(s) + 2H2O Substance Ag(s) H2S(g) O2(g) Ag2S(s) H2O a. b. c. d. e.
(kJ/mol) 0 20.6 0 32.6 285.8
8.80 kJ 69.9 kJ 22.1 kJ 90.8 kJ 40.5 kJ
ANS: A OBJ: Calculate the heat released using the balanced reaction, heats of formation, and mass of reactant. TOP: Hess's Law 40. How much heat is released or absorbed in the reaction of 10.0 grams of SiO2 (quartz) with excess hydrofluoric acid? SiO2(s) + 4HF(aq) SiF4(g) + 2H2O 910.9 320.8 1615 285.8 (kJ/mol) a. b. c. d. e.
1.25 kJ absorbed 1.25 kJ released 11.3 kJ absorbed 11.3 kJ released 6.56 kJ released
Whitten 10e
Test Bank
526
ANS: A DIF: Harder Question OBJ: Calculate the heat released or absorbed using the balanced reaction, heats of formation, and mass of reactant. TOP: Hess's Law 41. How much heat would be released or absorbed if 575 g of H2 are produced? CH4(g) + H2O(g) 3H2(g) + CO(g) = 205.9 kJ a. b. c. d. e.
1.97 104 kJ 5.90 104 kJ 3.54 105 kJ 7.08 105 kJ 1.97 105 kJ
ANS: A OBJ: Calculate the heat released or absorbed using the balanced reaction, heats of formation, and mass of product. TOP: Hess's Law 42. How much heat would be released if 12.0 g of methane, CH4, was completely burned in oxygen to form carbon dioxide and water at standard state conditions? for CH4(g) = 74.81 kJ/mol, for CO2(g) = 393.5 kJ/mol and for H2O = 285.8 kJ/mol a. 77.5 kJ b. 453 kJ c. 668 kJ d. 190. kJ e. 890. kJ ANS: C OBJ: Calculate the heat released using heats of formation and mass of reactant. TOP: Hess's Law 43. Calculate the standard heat of vaporization, 511.3 kJ/mol for SnCl4 a. 39.8 b. 16.4 c. 26.4 d. 44.8 e. 53.2
, for tin(IV) chloride, SnCl4, in kJ per mole.
=
and 471.5 kJ/mol for SnCl4(g).
ANS: A DIF: Harder Question OBJ: Calculate a heat of vaporization given heats of formation. TOP: Hess's Law 44. Which of the following techniques cannot be used to calculate Hrxn? a. Calorimetry b. Using melting points of reactants and products c. Hess's Law d. Using of Heats of Formation of reactants and products e. Using bond energies of reactants and products Whitten 10e
Test Bank
527
ANS: B OBJ: Identify the method that cannot be used to determine heats of reaction. TOP: Bond Energies 45. The heat of reaction of one of the following reactions is the average bond energy for the N-H bond in NH3. Which one? a. 2NH3(g) N2(g) + 3H2(g) b. NH3(g) 1/2N2(g) + 3/2H2(g) c. 1/3NH3(g) 1/3N(g) + H(g) d. 2/3NH3(g) 1/3N2(g) + H2(g) e. 1/3N(g) + H(g) 1/3NH3(g) ANS: C OBJ: Identify the chemical equation in which the heat of reaction equals the average bond energy of a compound. TOP: Bond Energies 46. Evaluate H0 for the following reaction from the given bond energies. 2HBr(g) H2(g) + Br2(g) HHH = 436 kJ/mol, HBrBr = 193 kJ/mol, HHBr = 366 kJ/mol a. b. c. d. e.
103 kJ 143 kJ +103 kJ +142 kJ 259 kJ
ANS: C DIF: Harder Question OBJ: Calculate the heat released or absorbed using the balanced reaction and bond energies. TOP: Bond Energies 47. Estimate the enthalpy change for the reaction below from the average bond energies given. There are two ClCl and two CH bonds in CH2Cl2. Remember that energy is absorbed when bonds are broken and released when they are formed. CH4(g) + 2Cl2(g) CH2Cl2(g) + 2HCl(g)
CH HCl a. b. c. d. e.
Average Bond Energies 413 kJ/mol ClCl 432 kJ/mol CCl
242 kJ/mol 339 kJ/mol
232 kJ/mol +578 kJ/mol +232 kJ/mol 578 kJ/mol +541 kJ/mol
ANS: A OBJ: Calculate the heat released or absorbed using the balanced reaction and bond energies. TOP: Bond Energies
Whitten 10e
Test Bank
528
48. Estimate the heat of reaction at 298 K for the reaction shown, given the average bond energies below. Br2(g) + 3F2(g) 2BrF3(g) Bond BrBr FF BrF a. b. c. d. e.
Bond Energy 193 kJ/mol 155 kJ/mol 249 kJ/mol
836 kJ 150 kJ 89 kJ 665 kJ 1222 kJ
ANS: A OBJ: Calculate the heat released or absorbed using the balanced reaction and bond energies. TOP: Bond Energies 49. Calculate the average NH bond energy in NH3(g). 472.7 kJ/mol, a. 46.11 kJ b. 15.4 kJ c. 390.9 kJ d. 264.5 kJ e. 1173 kJ
for H(g) = 218.0 kJ/mol,
for NH3(g) = 46.11 kJ/mol,
for N2(g) = 0 kJ/mol,
for N(g) =
for H2(g) = 0 kJ/mol.
ANS: C OBJ: Calculate an average bond energy given enthalpies of formation. TOP: Bond Energies 50. Calculate the average SF bond energy in SF6. kJ/mol, and for F(g) = 78.99 kJ/mol. a. 1962 kJ b. 1209 kJ c. 200.8 kJ d. 327.0 kJ e. 1565 kJ
for SF6(g) = 1209 kJ/mol, for S(g) = 278.8
ANS: D OBJ: Calculate an average bond energy given enthalpies of formation. TOP: Bond Energies 51. Given: HH bond energy = 435 kJ, ClCl bond energy = 243 kJ, and the standard heat of formation of HCl(g) is 92 kJ/mol, calculate the HCl bond energy. a. 431 kJ b. 247 kJ c. 180 kJ d. 4.6 kJ e. 326 kJ
Whitten 10e
Test Bank
529
ANS: A OBJ: Calculate the bond energy of a compound given reactant bond energies and the product heat of formation.. TOP: Bond Energies 52. Calculate the average bond energy in kJ per mol of bonds for the CH bond from the following data: C(graphite) + 2H2(g) CH4(g) = 74.81 kJ for H(g) = 218.0 kJ a. b. c. d. e.
for C(g) = 716.7 kJ
590.4 kJ/mol 1011 kJ/mol 415.9 kJ/mol 1665 kJ/mol 1229 kJ/mol
ANS: C OBJ: Calculate an average bond energy of a compound given the balanced thermochemical equation and enthalpies of formation TOP: Bond Energies 53. The for gaseous acetylene, HCCH, is 227 kJ/mol. What is the CC bond energy? The bond energies are 423 kJ/mol for CH and 436 kJ/mol for HH. The heat of sublimation for carbon is 717 kJ/mol. a. 98 kJ/mol b. 348 kJ/mol c. 986 kJ/mol d. 817 kJ/mol e. 1251 kJ/mol ANS: D OBJ: Calculate a bond energy of a compound given an enthalpy of formation and other bond energies. TOP: Bond Energies 54. Which of the following statements about internal energy, E, is false? a. It represents all the energy within a certain amount of matter. b. In some processes E = q c. In some processes E = q + w d. E is positive in exothermic reactions. e. Its absolute value cannot be determined. ANS: D OBJ: Identify the incorrect description of internal energy. TOP: Changes in Internal Energy, Delta E
Whitten 10e
Test Bank
530
55. Consider the following reaction at constant pressure. Which response is true? N2(g) + O2(g) 2NO(g) a. b. c. d.
Work is done on the system as it occurs. Work is done by the system as it occurs. No work is done as the reaction occurs. Work may be done on or by the system as the reaction occurs, depending upon the temperature. e. The amount of work depends on the pressure. ANS: C OBJ: Identify the correct description of a balanced reaction. TOP: Changes in Internal Energy, Delta E 56. Which statement concerning sign conventions for E = q + w is false? a. For heat absorbed by the system, q is positive. b. For work done by the system, w is negative. c. When energy is released by the reacting system, E is negative. d. If E is positive, energy can be written as a product in the equation for the reaction. e. For an expansion, w is negative. ANS: D OBJ: Identify the correct incorrect description of sign conventions. TOP: Changes in Internal Energy, Delta E 57. Consider the following reaction occurring at constant pressure and temperature, for which the value of E is negative. Which response is false? CH4(g) + 2O2(g) CO2(g) + 2H2O a. b. c. d. e.
Work is done by the surroundings on the system. Work is positive. Heat is released by the system. The volume must increase at constant pressure. All of these statements are true.
ANS: D OBJ: Identify the correct description of a chemical reaction given the sign of delta E. TOP: Changes in Internal Energy, Delta E 58. A 1.00-g sample of hexane, C6H14, undergoes complete combustion with excess O2 in a bomb calorimeter. The temperature of the 1500. g of water surrounding the bomb rises from 22.64C to 29.30C. The heat capacity of the calorimeter is 4.04 kJ/C. What is E for the reaction in kJ/mol of C6H14. The specific heat of water is 4.184 J/gC. a. 9.96 103 kJ/mol b. 4.52 103 kJ/mol c. 1.15 104 kJ/mol d. 7.40 104 kJ/mol e. 5.91 103 kJ/mol ANS: E OBJ: Calculate delta E for a reaction given bomb calorimetry data. TOP: Changes in Internal Energy, Delta E
Whitten 10e
Test Bank
531
59. A 0.900-g sample of toluene, C7H8, was completely burned in a bomb calorimeter containing 4560. g of water which increased in temperature from 23.800C to 25.718C. What is E for the reaction in kJ/mol C7H8? The heat capacity of the calorimeter was 780. J/C. The specific heat of water is 4.184 J/gC. a. 4520 kJ/mol b. +3500 kJ/mol c. 38.1 kJ/mol d. 2220 kJ/mol e. 3900 kJ/mol ANS: E OBJ: Calculate delta E for a reaction given bomb calorimetry data. TOP: Changes in Internal Energy, Delta E 60. A system is compressed from 50.0 L to 5.0 L at a constant pressure of 10.0 atm. What is the amount of work done? a. 2.5 105 J b. 450 J c. 4.6 104 J d. 450 J e. 4.6 104 J ANS: C OBJ: Calculate the work done under constant pressure. TOP: Changes in Internal Energy, Delta E 61. Assuming the gases are ideal, calculate the amount of work done, in joules, for the conversion of 1.00 mole of Ni to Ni(CO)4 at 75C in the reaction below. The value of R is 8.314 J/molK. Ni(s) + 4CO(g) Ni(CO)4(g) a. b. c. d. e.
1.80 103 J 8.68 103 J 1.80 103 J 8.68 103 J 494 J
ANS: B OBJ: Calculate the work done given moles of reactant and the balanced gaseous reaction. TOP: Changes in Internal Energy, Delta E 62. Assuming the gases are ideal, calculate the amount of work done, in joules, for the conversion of 2.00 mole of NO2 to N2O4 at 125C in the reaction below. The value of R is 8.314 J/molK. 2NO2(g) N2O4(g) a. b. c. d. e.
1,040 J 3,300 J 3,300 J 6,600 J 1,040 J
ANS: B OBJ: Calculate the work done given moles of reactant and the balanced gaseous reaction. TOP: Changes in Internal Energy, Delta E Whitten 10e
Test Bank
532
63. Which one of the following statements is false? a. The change in internal energy, E, for a process is equal to the amount of heat absorbed at constant volume, qv. b. The change in enthalpy, H, for a process is equal to the amount of heat absorbed at constant pressure, qp. c. A bomb calorimeter measures H directly. d. If qp for a process is negative, the process must be exothermic. e. The work done in a process occurring at constant pressure is zero if ngases is zero. ANS: C OBJ: Identify the incorrect description of delta E, delta H, q, and work. TOP: Relationship Between Delta H and Delta E 64. Which one of the following statements is false? a. The amount of heat absorbed by a system at constant volume, qv, is E for the process. b. The amount of heat absorbed by a system at constant pressure, qp, is H for the process. c. In the relationship E = q + w, as applied to a typical chemical reaction, w is usually much larger than q. d. At constant temperature and pressure, the work done by a system involving gases is ngases(RT) where ngas = nproduct gases nreactant gases for the process of interest. e. At constant pressure, the work done in a process by a system involving gases can be expressed as PV. ANS: C OBJ: Identify the incorrect description of delta E, delta H, and work. TOP: Relationship Between Delta H and Delta E 65. Which one of the following statements is false? For a reaction carried out at constant temperature and constant pressure in an open container, ____. a. the work done by the system can be set equal to PV b. the work done by the system can be set equal to VP c. the work done by the system can be set equal to nRT where n is the number of moles of gaseous products minus the number of moles of gaseous reactants d. the heat absorbed by the system can be called qp e. the heat absorbed by the system can be called H ANS: B OBJ: Identify the incorrect description a reaction done at constant temperature and pressure. TOP: Relationship Between Delta H and Delta E 66. Which statement is false? a. The thermodynamic quantity most easily measured in a "coffee cup" calorimeter is H. b. No work is done in a reaction occurring in a bomb calorimeter. c. H is sometimes exactly equal to E. d. H is often nearly equal to E. e. H is equal to E for the process: 2H2(g) + O2(g) 2H2O(g). ANS: E OBJ: Identify the incorrect description of delta E, delta H, and work. TOP: Relationship Between Delta H and Delta E
Whitten 10e
Test Bank
533
67. The reaction of 1.00 mole of H2(g) with 0.500 mole of O2(g) to produce 1.00 mole of steam, H2O(g), at 100C and 1.00 atm pressure evolves 242 kJ of heat. Calculate E per mole of H2O(g) produced. The universal gas constant is 8.314 J/molK. a. +240 kJ b. 240 kJ c. +242 kJ d. 242 kJ e. 238 kJ ANS: B OBJ: Calculate delta E given the thermochemical reaction data. TOP: Relationship Between Delta H and Delta E 68. Calculate E0 for the reaction below at 25C. SiO2(s) + 4HF(aq) 910.9 320.8 (kJ/mol) a. b. c. d. e.
SiF4(g) 1615
+ 2H2O 285.8
7.5 kJ/mol 5.02 kJ/mol 5.02 kJ/mol 5.23 kJ/mol 12.5 kJ/mol
ANS: B OBJ: Calculate delta E given the balanced reaction and enthalpies of formation. TOP: Relationship Between Delta H and Delta E 69. Calculate the standard energy change, E0, for the reaction below. 12NH3(g) + 21O2(g) 8HNO3 0 45.9 133.9 (kJ/mol) a. b. c. d. e.
+ 4NO(g) 91.3
+ 14H2O(g) 241.8
3,540 kJ/mol 201.3 kJ/mol 2,259 kJ/mol 4270 kJ/mol 3,503 kJ/mol
ANS: E OBJ: calculate delta E given the balanced reaction and enthalpies of formation. TOP: Relationship Between Delta H and Delta E 70. Which of the following statements regarding spontaneous changes is false? a. Spontaneity is favored when heat is released. b. Spontaneity is favored when the dispersal of matter is increased. c. Spontaneous changes occur at a given state without any outside influence. d. Ice melting at 25C is spontaneous primarily due to the increase in molecular disorder (dispersal of matter). e. All exothermic reactions are spontaneous. ANS: E OBJ: Identify the statement that is not a correct description of spontaneity. TOP: The Two Aspects of Spontaneity
Whitten 10e
Test Bank
534
71. Which situation does not represent a dispersal of matter? a. A gas expands into a vacuum. b. A sugar cube dissolves in a cup of coffee. c. Water freezes to form ice. d. Soap and water are mixed in a sink. e. Dye is dropped into a glass of water. ANS: C OBJ: Identify the process which does not involve a dispersal of energy. TOP: Dispersal of Energy and Matter 72. Which statement about the dispersal of matter and energy is false? a. Dispersal of energy in a system results in energy being spread over many particles. b. Dispersal of matter results in a more ordered system. c. The greater the number of molecules and the higher the total energy of the system are, the less likely the energy will be concentrated in a few molecules. d. Matter being dispersed is statistically a more probable outcome. e. There are two ways that the final state can be more probable than its initial state. ANS: B OBJ: Identify the correct description of dispersal of matter and energy. TOP: Dispersal of Energy and Matter 73. A positive change in entropy represents: a. an increase in dispersal of matter (molecular disorder) b. release of thermal energy c. a decrease in thermal energy d. a process that is always spontaneous e. a process that cannot occur spontaneously ANS: A OBJ: Define change in entropy. TOP: Entropy, S, and Entropy Change, Delta S 74. What is the entropy change of the reaction below at 298 K and 1 atm pressure? N2(g) + 3H2(g) 2NH3(g) 191.5 130.6 192.3 (J/molK) a. b. c. d. e.
198.7 J/K 76.32 J/K 129.7 J/K 303.2 J/K 384.7 J/K
ANS: A OBJ: Calculate the change in entropy given the balanced equation and absolute entropies. TOP: Entropy, S, and Entropy Change, Delta S
Whitten 10e
Test Bank
535
75. Evaluate S0 for the reaction below at 25C and 1 atm. 3NO2(g) + H2O 0 240 69.91 S (J/molK) a. b. c. d. e.
2HNO3(aq) 146
+ NO(g) 210.7
+1.37 103 J/K +287.2 J/K 287.2 J/K +1.37 103 J/K 531.4 J/K
ANS: C OBJ: Calculate the change in entropy given the balanced equation and absolute entropies. TOP: Entropy, S, and Entropy Change, Delta S 76. Calculate S0 for the reaction below at 25C. S0 for SiH4 = 204.5 J/molK, for O2(g) = 205.0 J/molK, for SiO2(s) = 41.84 J/molK, for H2O = 69.91 J/molK. SiH4(g) + 2O2(g) SiO2(s) + 2H2O a. b. c. d. e.
353.5 J/K 432.8 J/K 595.0 J/K 677.0 J/K 880.3 J/K
ANS: B OBJ: Calculate the change in entropy given the balanced equation and absolute entropies. TOP: Entropy, S, and Entropy Change, Delta S 77. If the entropy change for the reaction below at 298 K and 1 atm pressure is 137 J/K and S0 = 205 J/molK for O2(g), what is S0 for O3(g)? 2O3(g) 3O2(g) a. b. c. d. e.
364 J/molK 478 J/molK 239 J/molK 117 J/molK 59 J/molK
ANS: C OBJ: Calculate the missing absolute entropy. TOP: Entropy, S, and Entropy Change, Delta S 78. The heat of vaporization of methanol, CH3OH, is 35.20 kJ/mol. Its boiling point is 64.6C. What is the change in entropy for the vaporization of methanol? a. 17.0 J/molK b. 3.25 J/molK c. 17.0 J/molK d. 104 J/molK e. 543 J/molK
Whitten 10e
Test Bank
536
ANS: D OBJ: Calculate the entropy change of the formation of a vapor given heat of vaporization and boiling point. TOP: Entropy, S, and Entropy Change, Delta S 79. Which of the following statements regarding the third law of thermodynamics is incorrect? a. The absolute S is zero at 0 Kelvin. b. The absolute S at 298 K can be positive or negative. c. Pure substances have positive absolute S at T > 0 Kelvin. d. Absolute zero gives a reference point for determining absolute S. e. The absolute S is greater at 300 K than 100 K for a given substance. ANS: B OBJ: Identify the incorrect description of the third law. TOP: Entropy, S, and Entropy Change, Delta S 80. Which of following would have the highest value of absolute entropy per mole? a. water at 50C b. water at 10C c. ice at 10C d. 1 M NaCl at 50C e. 1 M NaCl at 10C ANS: D OBJ: Identify the substance with the highest absolute entropy per mole. TOP: Entropy, S, and Entropy Change, Delta S 81. Which one of the following reactions has a positive entropy change? a. H2O(g) H2O b. BF3(g) + NH3(g) F3BNH3(s) c. 2SO2(g) + O2(g) 2SO3(g) d. N2(g) + 3H2(g) 2NH3(g) e. 2NH4NO3(s) 2N2(g) + 4H2O(g) + O2(g) ANS: E OBJ: Identify the chemical reaction with a positive change in entropy. TOP: Entropy, S, and Entropy Change, Delta S 82. Which chemical change listed below represents a decrease in entropy? a. N2(g) + 3H2(g) NH3(g) b. CaCO3(s) CaO(s) + CO2(g) c. 2NO2(g) N2(g) + 2O2(g) d. 2C6H6 + 15O2(g) 12CO2(g) + 6H2O(g) e. 2NaCl 2Na + Cl2(g) ANS: A OBJ: Identify the chemical reaction with a decrease in entropy. TOP: Entropy, S, and Entropy Change, Delta S
Whitten 10e
Test Bank
537
83. Which physical change listed below would have a negative value of S? a. The sublimation (vaporization) of dry ice (solid CO2). b. Boiling water. c. Evaporation of water from a lake. d. Sugar dissolving in coffee. e. Rain drops forming in a cloud. ANS: E OBJ: Identify the physical change consistent with a negative change in entropy. TOP: Entropy, S, and Entropy Change, Delta S 84. Which of the following changes represent a decrease in entropy? a. Condensation of steam on glass b. Evaporation of gasoline c. Decomposition of fallen leaves d. Melting snow e. Diffusion of perfume throughout a room ANS: A OBJ: Identify the physical consistent with a decrease in entropy. TOP: Entropy, S, and Entropy Change, Delta S 85. The second law of thermodynamics states: a. All exothermic processes also increase entropy. b. The enthalpy of the universe always increases in spontaneous processes. c. A spontaneous process always increases entropy. d. H < 0 and S > 0 for all spontaneous processes e. The entropy of the universe always increases in spontaneous processes. ANS: E OBJ: Define the second law. TOP: The Second Law of Thermodynamics 86. A flask containing helium gas is released into a closed room. Which of the following ideas regarding entropy is false? a. Ssystem > 0 b. Matter is dispersed. c. Suniverse > 0 d. This process is spontaneous. e. All of these statements are true. ANS: E OBJ: Identify the incorrect description of entropy. TOP: The Second Law of Thermodynamics 87. A process occurs spontaneously and Ssystem < 0. Which statement below must be true? a. Ssurroundings > 0 b. Suniverse > 0 c. The pressure is constant. d. Both (a) and (b) are correct. e. All of these answers are correct.
Whitten 10e
Test Bank
538
ANS: D OBJ: Identify the statements consistent with the given conditions of spontaneity and change in entropy of the system. TOP: The Second Law of Thermodynamics 88. Consider the conversion of a substance from solid to liquid. Solid Liquid At one atmosphere pressure and at the melting point of the substance, ____. a. H = 0 for the process b. S = 0 for the process c. E = 0 for the process d. G = 0 for the process e. both H = 0 and E = 0 for the process ANS: D OBJ: Identify the correct description of the physical change. TOP: Free Energy Change, Delta G, and Spontaneity 89. Which of the following statements about free energy is false? a. If S is negative then H must be negative for a spontaneous process. b. S is positive for many spontaneous processes. c. G is always negative for spontaneous processes. d. G is always positive for nonspontaneous processes. e. S must be positive for a process to be spontaneous. ANS: E OBJ: Identify the incorrect description of free energy. TOP: Free Energy Change, Delta G, and Spontaneity 90. Calculate G0 for the reaction below. The standard molar entropy change for the reaction at 298 K is 287.5 J/molK. 3NO2(g) + H2O 2HNO3(aq) + NO(g) + 136.8 kJ a. b. c. d. e.
51.2 kJ/mol 85,500 kJ/mol 68.4 kJ/mol 236 kJ/mol 222 kJ/mol
ANS: A OBJ: Calculate delta G for the balanced thermochemical reaction given the entropy change. TOP: Free Energy Change, Delta G, and Spontaneity 91. Evaluate G0 for the reaction below at 25C. 2C2H2(g) + 5O2(g) 209.2 0 (kJ/mol) a. b. c. d. e.
4CO2(g) 394.4
+ 2H2O 237.2
1409 kJ 2599 kJ 1643 kJ 2470 kJ 766 kJ
Whitten 10e
Test Bank
539
ANS: D OBJ: Calculate delta G given delta G's of formation for the balanced chemical reaction. TOP: Free Energy Change, Delta G, and Spontaneity 92. Calculate the standard Gibbs free energy change for the following reaction at 25C. CaCO3(s) + 2HCl(g) CaCl2(s) + CO2(g) + H2O 1129 95.3 750.2 394.4 237.2 (kJ/mol) a. b. c. d. e.
41 kJ 158 kJ 62 kJ 87 kJ 104 kJ
ANS: C OBJ: Calculate delta G given delta G's of formation for the balanced chemical reaction. TOP: Free Energy Change, Delta G, and Spontaneity 93. Calculate the at 298 K for PbCl2(s) from the following information. G0 for the reaction below is 58.4 kJ at 298 K. PbS(s) + 2HCl(g) PbCl2(s) + H2S(g) ? 98.7 95.30 33.6 (kJ/mol) a. b. c. d. e.
16.0 kJ/mol 47.6 kJ/mol 314.1 kJ/mol 36.2 kJ/mol 52.3 kJ/mol
ANS: C OBJ: Calculate the missing delta G of formation. TOP: Free Energy Change, Delta G, and Spontaneity 94. Calculate G0 at 298 K for the reaction below. N2O4(g) + 2N2H4 97.82 149.0 (kJ/mol) a. b. c. d. e.
3N2(g) 0
+ 4H2O(g) 228.6
518.1 kJ/mol 475.6 kJ/mol 1311 kJ/mol 1311 kJ/mol 667.1 kJ/mol
ANS: C OBJ: Calculate delta G given delta G's of formation for the balanced chemical reaction. TOP: Free Energy Change, Delta G, and Spontaneity
Whitten 10e
Test Bank
540
95. Calculate G0 at 298 K for the reaction below. Fe2O3(s) + 13CO(g) 824.2 110.5 (kJ/mol) S0 (J/molK) a. b. c. d. e.
87.4
2Fe(CO)5(g) 733.8
+ 3CO2(g) 393.5
445.2
213.6
197.6
+63.6 kJ +26.8 kJ 243.1 kJ 52.2 kJ 193.3 kJ
ANS: D OBJ: Calculate delta G given enthalpies of formation and absolute entropies for the reactants and products of the balanced reaction. TOP: Free Energy Change, Delta G, and Spontaneity 96. Determine G0 for the reaction: 2CO(g) + 2H2(g) CO2(g) + CH4(g) H0 = 247.3 kJ/mol a. b. c. d. e.
S0 = 256.5 J/mol K
182.8 kJ/mol 253.7 kJ/mol 170.9 kJ/mol 76,200 J/mol 323.9 kJ/mol
ANS: C OBJ: Calculate delta G using the change in enthalpy and entropy of the reaction. TOP: Free Energy Change, Delta G, and Spontaneity 97. Evaluate (kJ/mol) S (J/molK) 0
a. b. c. d. e.
for the following reaction at 25C. 2ZnS(s) + 3O2(g) 0 205.6 57.7
205.0
2ZnO(s) 348.3
+ 2SO2(g) 296.8
43.64
248.1
951.1 kJ 922.6 kJ 704.2 kJ 835.2 kJ 1902 kJ
ANS: D OBJ: Calculate delta G given enthalpies of formation and absolute entropies for the reactants and products of the balanced reaction. TOP: Free Energy Change, Delta G, and Spontaneity 98. For the following reaction at 25C, H0 = 26.88 kJ and S0 = 11.2 J/K. Calculate G0 for the reaction at 25C in kilojoules. I2(g) + Cl2(g) 2ICl(g)
Whitten 10e
Test Bank
541
a. b. c. d. e.
102 kJ +50.6 kJ 30.2 kJ 50.6 kJ +77.0 kJ
ANS: C OBJ: Calculate delta G using the change in enthalpy and entropy of the reaction. TOP: Free Energy Change, Delta G, and Spontaneity 99. Evaluate G0 for the reaction below at 25C. P4O10(s) + 6H2O 2984 285.8 (kJ/mol) 228.9 69.91 S0 (J/molK) a. b. c. d. e.
4H3PO4(s) 1281 110.5
50.33 kJ 172.0 kJ 282.5 kJ 304.8 kJ 363.7 kJ
ANS: E OBJ: Calculate delta G given enthalpies of formation and absolute entropies for the reactants and products of the balanced reaction. TOP: Free Energy Change, Delta G, and Spontaneity 100. Evaluate
for the following reaction at 25C. 2N2(g) + 3O2(g) 2N2O3(g) S0
N2(g) O2(g) N2O3(g) a. b. c. d. e.
83.72 kJ/mol
191.5 J/molK 205.0 J/molK 312.2 J/molK
+540.0 kJ +278.8 kJ 540.0 kJ 56.1 kJ +56.1 kJ
ANS: B OBJ: Calculate delta G given enthalpies of formation and absolute entropies for the reactants and products of the balanced reaction. TOP: Free Energy Change, Delta G, and Spontaneity 101. Estimate the temperature at which G = 0 for the following reaction. NH3(g) + HCl(g) NH4Cl(s) H = 176 kJ; S = 284.5 J/K
Whitten 10e
Test Bank
542
a. b. c. d. e.
467 K 582 K 619 K 634 K 680 K
ANS: C OBJ: Calculate the temperature at which delta G is zero given delta H and S of a reaction. TOP: The Temperature Dependence of Spontaneity 102. Estimate the boiling point of water if for H2O for H2O(g), a. 101 K b. 387 K c. 398 K d. 370 K e. 274 K
,
= 285.8 kJ/mol and S0 = 69.91 J/molK and
= 241.8 kJ/mol and S0 = 188.7 J/molK.
ANS: D OBJ: Calculate the boiling point of water given enthalpies of formation and absolute entropies. TOP: The Temperature Dependence of Spontaneity 103. A process cannot be spontaneous (product-favored) if ____. a. it is exothermic, and there is an increase in disorder b. it is endothermic, and there is an increase in disorder c. it is exothermic, and there is a decrease in disorder d. it is endothermic, and there is a decrease in disorder e. the entropy of the universe increases ANS: D OBJ: Identify the parameters that are consistent with a nonspontaneous process. TOP: The Temperature Dependence of Spontaneity 104. Which one of the following statements is not correct? a. When G for a reaction is negative, the reaction is spontaneous. b. When G for a reaction is positive, the reaction is nonspontaneous. c. When G for a reaction is zero, the system is at equilibrium. d. When H for a reaction is negative, the reaction is never spontaneous. e. When H for a reaction is very positive, the reaction is not expected to be spontaneous. ANS: D OBJ: Identify the description of delta G or delta H that is not correct. TOP: The Temperature Dependence of Spontaneity 105. For the reaction given below, H0 = 1516 kJ at 25C and S0 = 432.8 J/K at 25C. This reaction is spontaneous ____. SiH4(g) + 2O2(g) SiO2(s) + 2H2O
Whitten 10e
Test Bank
543
a. b. c. d. e.
only below a certain temperature only above a certain temperature at all temperatures at no temperatures cannot tell from the information available
ANS: A OBJ: Determine if a reaction is spontaneous given delta H and S. TOP: The Temperature Dependence of Spontaneity 106. Which statement below is false? a. For reactions that release heat to the surroundings, H is negative. b. For reactions in which the reacting system becomes more disordered, S is positive. c. If the free energy change of reaction is positive, the reaction cannot occur to give predominantly products under the given conditions. d. The entropy of a system increases when order increases. e. Endothermic reactions may be spontaneous. ANS: D OBJ: Identify the incorrect description of enthalpy, entropy, and spontaneity. TOP: The Temperature Dependence of Spontaneity 107. Which of the following reactions is spontaneous at relatively low temperatures? a. NH4Br(s) + 188 kJ NH3(g) + Br2 b. NH3(g) + HCl(g) NH4Cl(s) + 176 kJ c. 2H2O2 2H2O + O2(g) + 196 kJ d. both (a) and (b) e. both (a) and (c) ANS: B OBJ: Identify the chemical reaction that is spontaneous at low temperatures. TOP: The Temperature Dependence of Spontaneity 108. Consider the reaction below at 25C for which S0 = 16.1 J/K. CH4(g) + N2(g) + 163.8 kJ HCN(g) + NH3(g) Which one of the following statements describes the reaction? a. Spontaneous at all temperatures b. Spontaneous at relatively low temperatures only c. Spontaneous at relatively high temperatures only d. Nonspontaneous at all temperatures e. Insufficient information to estimate temperature range of spontaneity ANS: C OBJ: Identify the conditions at which a balanced thermochemical reaction is spontaneous, given also delta S. TOP: The Temperature Dependence of Spontaneity
Whitten 10e
Test Bank
544
109. Consider the following equation carefully, and determine the sign of S0 for the reaction it describes. NH4Br(s) NH3(g) + HBr(g) = +188.3 kJ Which response describes the thermodynamic spontaneity of the reaction? a. The reaction is spontaneous at all temperatures. b. The reaction is spontaneous only at relatively high temperatures. c. The reaction is spontaneous only at relatively low temperatures. d. The reaction is not spontaneous at any temperatures. e. We cannot tell from information given. ANS: B OBJ: Determine the sign of delta S given the balanced thermochemical equation. TOP: The Temperature Dependence of Spontaneity 110. For which set of values of H and S will a reaction be spontaneous (product-favored) at all temperatures? a. H = +10 kJ, S = 5 J/K b. H = 10 kJ, S = 5 J/K c. H = 10 kJ, S = +5 J/K d. H = +10 kJ, S = +5 J/K e. no such values exist ANS: C OBJ: Identify the combination of delta H and S that gives a spontaneous reaction at all temperatures. TOP: The Temperature Dependence of Spontaneity 111. Joseph Priestley prepared oxygen by heating mercury(II) oxide. The compound HgO is stable at room temperature but decomposes into its elements (Hg and O2) at high temperatures. What conclusions can be drawn concerning H and S for this decomposition reaction? a. H is negative and S is positive. b. H is negative and S is negative. c. H is positive and S is positive. d. H is positive and S is negative. e. H becomes negative at high temperatures. ANS: C OBJ: Identify the sign of delta H and S given a description of a reaction. TOP: The Temperature Dependence of Spontaneity 112. The following reaction is spontaneous only below 3000 K. What conclusions can be drawn regarding this reaction? A + B AB a. b. c. d. e.
H is negative and S is positive. H is negative and S is negative. H is positive and S is positive. H is positive and S is negative. Cannot conclude anything.
ANS: B OBJ: Identify the sign of delta H and S given the temperature limits of spontaneity. TOP: The Temperature Dependence of Spontaneity
Whitten 10e
Test Bank
545
113. For a certain process at 127C, G = 16.20 kJ and H = 17.0 kJ. What is the entropy change for this process at this temperature? Express your answer in the form, S = ____ J/K. a. 6.3 J/K b. +6.3 J/K c. 2.0 J/K d. +2.0 J/K e. 8.1 J/K ANS: C OBJ: Calculate delta S given delta G and delta H. TOP: The Temperature Dependence of Spontaneity 114. For a certain process at 27C, G = +210.6 kJ and H = 168.2 kJ. What is the entropy change for this process at this temperature? Express your answer in the form, S = ____ J/K. a. 1.26 103 J/K b. 1.26 103 J/K c. 141.3 J/K d. +141.3 J/K e. +628.3 J/K ANS: B OBJ: Calculate delta S given delta G and delta H. TOP: The Temperature Dependence of Spontaneity 115. The following reaction has G = 0 at 9900C. What is the value of S0 for the reaction? At 298 K: CH4(g) + N2(g) + 163.8 kJ HCN(g) + NH3(g) a. b. c. d. e.
16.5 J/molK 16.1 J/molK 62.1 J/molK 60.4 J/molK 16.1 J/molK
ANS: B OBJ: Calculate delta S given the balanced thermochemical reaction and the temperature at which delta G equals zero. TOP: The Temperature Dependence of Spontaneity 116. Consider the following reaction and its and 2C2H2(g) + 5O2(g) 4CO2(g) + 2H2O = 2599 kJ, = 2470 kJ a. b. c. d. e.
values at 25C. Evaluate
at 25C.
+340 J/K 340 J/K +386 J/K 433 J/K 386 J/K
ANS: D OBJ: Calculate delta S given delta G and delta H. TOP: The Temperature Dependence of Spontaneity
Whitten 10e
Test Bank
546
117. Evaluate S0 for the reaction below at 25C. CH4(g) + 2Cl2(g) 0 74.81 (kJ/mol) (kJ/mol) a. b. c. d. e.
50.75
0
CCl4 135.4
+ 2H2(g) 0
65.27
0
360 J/K 66.9 J/K 155 J/K 487 J/K 387 J/K
ANS: C OBJ: Calculate delta S given enthalpies of formation and free energies of formation for the reactants and products of the balanced reaction. TOP: The Temperature Dependence of Spontaneity 118. Calculate S0 at 25C for the reaction below. PbS(s) + 2HCl(g) 100.4 92.31 (kJ/mol) (kJ/mol) a. b. c. d. e.
98.7
95.30
PbCl2(s) 359.4
+ H2S(g) 20.6
314.1
33.6
686 J/K 741 J/K 123 J/K 1.33 103 J/K 515 J/K
ANS: C OBJ: Calculate delta S given enthalpies of formation and free energies of formation for the reactants and products of the balanced reaction. TOP: The Temperature Dependence of Spontaneity 119. For the following reaction, H0 = 104.9 kJ/mol. If this reaction is spontaneous at all temperatures below 361 K, what is the value of S0? a. 165 J/molK b. 0.291 J/molK c. 3.44 J/molK d. 291 J/molK e. 3.44 kJ ANS: D OBJ: Calculate delta S given the change in enthalpy of reaction and the temperature limits of spontaneity. TOP: The Temperature Dependence of Spontaneity
Whitten 10e
Test Bank
547
120. Estimate the temperature above which this reaction is spontaneous. S0 = 16.1 J/K. CH4(g) + N2(g) + 163.8 kJ HCN(g) + NH3(g) a. b. c. d. e.
9.91C 1045 K 9.90 103C 10.7 K 10.1C
ANS: C OBJ: Calculate the minimum reaction temperature required for spontaneity, given the balanced thermochemical reaction and delta S. TOP: The Temperature Dependence of Spontaneity 121. For a particular reaction at 25C, H0 = 297 kJ/mol, and S0 = 113.3 J/molK. At which of the following temperatures would the reaction become spontaneous? a. 2750 K b. 3250 K c. 2450 K d. 10500 K e. 3750 K ANS: C OBJ: Calculate the temperature required for spontaneity given delta H and delta S. TOP: The Temperature Dependence of Spontaneity 122. Priestley prepared oxygen by heating mercury(II) oxide. From the data given below estimate the temperature above which this reaction will become spontaneous. H0 = 90.83 kJ HgO(s) Hg + O2(g) S0(Hg) = 76.02 J/molK a. b. c. d. e.
S0(HgO) = 70.29 J/molK
S0(O2) = 205.0 J/molK
108 K 566 K 430 K 840 K 739 K
ANS: D OBJ: Calculate the temperature required for spontaneity given the balanced thermochemical reaction and absolute entropies. TOP: The Temperature Dependence of Spontaneity 123. At 25C H = 128.9 kJ and G = 33.5 kJ for a reaction. Above what minimum temperature will this reaction become spontaneous? a. 298 K b. 332 K c. 403 K d. 530 K e. 1150 K
Whitten 10e
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ANS: C DIF: Harder Question OBJ: Calculate the temperature required for spontaneity given delta H and delta G. TOP: The Temperature Dependence of Spontaneity 124. Estimate the temperature above which this reaction is nonspontaneous. PbS(s) + 2HCl(g) PbCl2(s) 100.4 92.31 359.4 (kJ/mol) (kJ/mol) a. b. c. d. e.
98.7
95.30
314.1
+ H2S(g) 20.6 33.6
144C 88C 16C 42C 499C
ANS: E DIF: Harder Question OBJ: Calculate the temperature above which the reaction is nonspontaneous given the balanced reaction, enthalpies of formation, and free energies of formation. TOP: The Temperature Dependence of Spontaneity 125. The energy associated with a motionless rock sitting atop a mountain is called _____. a. heat b. internal energy c. temperature d. kinetic energy e. potential energy ANS: E DIF: easy OBJ: Identify an example of potential energy. TOP: The First Law of Thermodynamics 126. If q = 84 kJ for a certain process, that process a. requires a catalyst. b. is endothermic. c. occurs slowly. d. is exothermic. e. cannot occur. ANS: B DIF: easy OBJ: Identify an exothermic or endothermic process given q (heat). TOP: Changes in Internal Energy, Delta E . 127. What is the change in internal energy of the system (E) if 18 kJ of heat energy is evolved by the system and 21 kJ of work is done on the system for a certain process? a. 3 kJ b. –39 kJ c. –18 kJ d. –3 kJ e. 39 kJ Whitten 10e
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ANS: A DIF: moderate OBJ: Calculate delta E given q (heat) and w (work). TOP: Changes in Internal Energy, Delta E 128. What is the change in enthalpy when 9.00 mol of sulfur trioxide decomposes to sulfur dioxide and oxygen gas? 2SO2(g) + O2(g) 2SO3(g); H° = 198 kJ/mol rxn a. b. c. d. e.
891 kJ –198 kJ –891 kJ 198 kJ 1782 kJ
ANS: C DIF: easy OBJ: Calculate the change in enthalpy given the moles of reactant consumed and the balanced thermochemical equation. TOP: Enthalpy Changes 129. A 8.56-g sample of solid silver reacted in excess chlorine gas to give a 11.4-g sample of pure solid AgCl. The heat given off in this reaction was 10.1 kJ at constant pressure. Given this information, what is the enthalpy of formation of AgCl(s)? a. –127 kJ/mol rxn b. –63.6 kJ/mol rxn c. 127 kJ/mol rxn d. –10.1 kJ/mol rxn e. 10.1 kJ/mol rxn ANS: A DIF: difficult OBJ: Calculate the enthalpy of formation of a substance given the change in enthalpy of a reaction. TOP: Standard Molar Enthalpies of Formation, Delta H°f 130. A 100 g sample of each of the following metals is heated from 35C to 45C. Which metal absorbs the greatest amount of heat energy? Metal copper magnesium mercury silver lead a. b. c. d. e.
Specific Heat 0.385 J/(g · °C) 1.02 J/(g · °C) 0.138 J/(g · °C) 0.237 J/(g · °C) 0.129 J/(g · °C)
magnesium lead copper mercury silver
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ANS: A DIF: easy OBJ: Identify the metal which absorbs the smallest or largest amount of heat given the specific heat capacities and change in temperature. TOP: Calorimetry 131. How much heat is gained by cobalt when 23.4 g of cobalt is warmed from 26.2°C to 63.2°C? The specific heat of cobalt is 0.421 J/(g · °C). a. 2.58 102 J b. 26.61 J c. 15.58 J d. 3.65 102 J e. 6.23 102 J ANS: D DIF: moderate OBJ: Calculate delta H of a substance given the specific heat capacity and change in temperature. TOP: Calorimetry 132. A 120.0-g sample of metal at 89.0°C is added to 120.0 g of H2O(l) at 17.0°C in an insulated container. The temperature rises to 23.2°C. Neglecting the heat capacity of the container, what is the specific heat of the metal? The specific heat of H2O(l) is 4.18 J/(g · °C). a. 4.18 J/(g · °C) b. 44.7 J/(g · °C) c. 0.391 J/(g · °C) d. –0.391 J/(g · °C) e. 10.7 J/(g · °C) ANS: C DIF: difficult OBJ: Calculate the specific heat capacity of a substance given calorimetry data. TOP: Calorimetry 133. Which of the following reactions corresponds to the thermochemical equation for the standard enthalpy of formation of solid calcium nitrate? a. Ca2+(aq) + 2NO3–(aq) Ca(NO3)2(s) b. Ca(OH)2(s) + 2HNO3(aq) Ca(NO3)2(s) + 2H2O(l) c. Ca(s) + N2(g) + 3O2(g) Ca(NO3)2(s) d. Ca(s) + 2HNO3(aq) Ca(NO3)2(s) + H2(g) e. Ca(s) + 2N(g) + 6O(g) Ca(NO3)2(s) ANS: C DIF: easy OBJ: Identify the chemical equation that represents an enthalpy of formation. TOP: Standard Molar Enthalpies of Formation, Delta H°f 134. Based on the following data, what is the Br-Br bond energy? H2(g) + Br2(g) HBr(g); H = –36.44 kJ/mol rxn Bond H-H H-Br
Bond Energy (kJ/mol) 435 362
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a. b. c. d. e.
399 kJ/mol 216 kJ/mol –216 kJ/mol –289 kJ/mol 289 kJ/mol
ANS: B DIF: moderate OBJ: Calculate the missing bond energy. TOP: Bond Energies
Are the following processes endothermic or exothermic? 135. Melting chocolate a. endothermic
b. exothermic
ANS: A OBJ: Determine if the process is endothermic or exothermic. TOP: Enthalpy Changes 136. Na Na + 1e a. endothermic +
-
b. exothermic
ANS: A OBJ: Determine if the process is endothermic or exothermic. TOP: Enthalpy Changes 137. Co(g) + Cl2(g) COCl2(g) a. endothermic
ΔH = -108kJ b. exothermic
ANS: B OBJ: Determine if the process is endothermic or exothermic. TOP: Enthalpy Changes 138. An automobile engine provides 551J of work to push the pistons and generates 2250J of heat
that must be carried away by the cooling system. Calculate the change in internal energy of the engine. a. 551J b. 1102J c. 1699J d. 2250J e. 2801J ANS: E OBJ: Calculate the change in internal energy. TOP: Changes in Internal Energy, Delta E 139. Using the following thermochemical equation:
2NH3(g) + 3N2O(g) 4N2(g) + 3H2O(g) ΔH = -880 kJ How much energy is released when 6.22g of ammonia, NH3, reacts with excess dinitrogen monoxide, N2O? a. -161 kJ b. -321 kJ c. -623 kJ d. -2740 kJ e. -5474 kJ ANS: A OBJ: Use stoichiometry to determine the change in enthalpy. TOP: Thermochemical Equations
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140. How much energy is required to raise the temperature of 10.9g of water from 22.9oC to
38.2oC? a. 38.5 J
b. 298 J
c. 698 J
d. 1040 J
e. 1740 J
ANS: C OBJ: Calculate the energy required to heat the given amount of water. TOP: Calorimetry 141. A sample of solid tin is heated with an electrical coil. If 39.6 J of energy are added to a 14.3g
sample initially at 24.2oC, what is the final temperature of the tin? cSn = 0.21J/g.oC a. 35.2oC b. 37.4oC c. 43.1oC d. 67.4oC e. 94.7oC ANS: B OBJ: Calculate the final temperature of a sample of metal. TOP: Calorimetry 142. The specific heat capacity of graphite, C(s), is 0.71J/g.oC. Calculate the molar heat capacity
of graphite. a. 0.059 J/mol.oC b. 0.12 J/moloC c. 1.4 J/moloC d. 8.5 J/moloC e. 17 J/moloC ANS: D OBJ: Convert a specific heat capacity to a molar enthalpy. TOP: Standard Molar Enthalpies of Formation, Delta H°f 143. What is the enthalpy change for the following reaction when 3.30 moles of oxygen react with
excess methane? CH4(g) + 2O2(g) CO2(g) + 2H2O(g) ΔH = -802 kJ a. -486.1 kJ b. -1203.0 kJ c. -1323.3 kJ d. -1604.0 kJ
e. -2646.6 kJ
ANS: C OBJ: Use stoichiometry to calculate the change in enthalpy. TOP: Thermochemical Equations 144. How much energy is required to decompose 765 g of PCl3, according to the following
reaction: a. 1680 kJ
4PCl3(g) P4(s) + 6Cl2(g) b. 2310 kJ c. 4330 kJ
ΔH = 1207 kJ d. 5950 kJ
e. 6720 kJ
ANS: A OBJ: Use stoichiometry to calculate the change in enthalpy. TOP: Thermochemical Equations 145. In the laboratory, a student burns a 0.415g sample of phenanthrene (C14H10) in a bomb
calorimeter. The temperature increased from 25.90oC to 28.90oC. Calculate the heat capacity of the calorimeter, if the heat of combustion of phenanthrene is 7054 kJ/mol. a. 5.47 kJ/oC b. 49.3 kJ/oC c. 656 kJ/oC d. 976 kJ/oC e. 2350 kJ/oC ANS: A OBJ: Calculate the heat capacity of the bomb calorimeter. TOP: Calorimetry Whitten 10e
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2 NiCl2(s) + O2(g) 2NiO(s) + 2Cl2(g) Given the enthalpy changes for the following two reactions: 2Ni(s) + O2(g) 2NiO(s) ΔHo = -479.4 kJ Ni(s) + Cl2(g) NiCl2(s) ΔHo = -305.3 kJ a. 131.2 kJ b. -174.1 kJ c. 610.6 kJ d. -784.7 kJ e. 1090.0 kJ
146. Calculate the enthalpy change for the reaction:
ANS: A OBJ: Sum the given balanced thermochemical equations to determine the enthalpy change. TOP: Hess's Law 147. A list of the calorie content of foods indicates that a 10 oz chocolate shake contains 353
Calories. Express this value in Joules. (1 Calorie = 1000 calories; 1 calorie = 4.18 Joules) a. 84.4 J b. 84,400 J c. 148 J d. 1480 J e. 1480,000 J ANS: E OBJ: Convert Calories to Joules. TOP: Energy 148. An automobile engine provides 637 Joules of work to push the pistons. In this process the
internal energy changes by -2767 Joules. Calculate the amount of heat that must be carried away by the cooling system. a. -2130 J b. 2130 J c. -3404 J d. 3404 J e. -2767 J ANS: A OBJ: Calculate the heat released given the work and internal energy changes. TOP: Changes in Internal Energy, Delta E 149. When HCl(g) reacts with NH3(g) to form NH4Cl(s) according to the following equation,
energy is released into the surroundings. HCl(g) + NH3(g) NH4Cl(s) Is this reaction endothermic or exothermic, and what is the sign of ΔH for this reaction? a. endothermic, + b. endothermic, c. exothermic, + d. exothermic, e. energy change is balanced by the surroundings, neutral ANS: D OBJ: Classify a reaction as endothermic or exothermic and indicate the sign of the change in enthalpy. TOP: Thermochemical Equations 150. When 1 mole of Fe2O3(s) reacts with H2(g) to form Fe(s) and H2O(g) according to the
following equation, 98.8 kJ of energy are absorbed. Fe2O3(s) + 3 H2(g) 2 Fe(s) + 3 H2O(g)
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Is the reaction endothermic or exothermic, and which of the enthalpy diagrams above represents this reaction? a. endothermic, A c. exothermic, A b. endothermic, B d. exothermic, B ANS: B OBJ: Classify the reaction as endothermic or exothermic. TOP: Thermochemical Equations 151. In the laboratory a student finds that it takes 49.3 Joules to increase the temperature of 10.2
grams of solid nickel from 24.7 to 36.3 degrees Celsius. The specific heat of nickel she has measured is: a. 0.0178 J/g.oC b. 0.417 J/g.oC c. 0.240 J/g.oC d. 0.561 J/g.oC e. 0.603 J/g.oC ANS: B OBJ: Calculate the specific heat capacity of a metal. TOP: Enthalpy Changes 152. The following information is given for water, H2O, at 1 atm:
boiling point = 100oC ΔHvap = 40.7 kJ/mol melting point = 0.000oC ΔHfus = 6.01 kJ/mol specific heat liquid = 4.18 J/goC At a pressure of 1 atm, how many kJ of heat are needed to vaporize a 39.6g sample of liquid water at its normal boiling point of 100oC? a. 13.2 kJ b. 16.6 kJ c. 89.4 kJ d. 238 kJ e. 1610 kJ ANS: C OBJ: Calculate the amount of energy required to change the phase of a substance. TOP: Enthalpy Changes
153. The following information is given for chromium at 1 atm:
boiling point = 2672oC ΔHvap = 305 kJ/mol melting point = 1857oC ΔHfus = 14.6 kJ/mol specific heat solid = 0.460 J/goC specific heat liquid = 0.937 J/goC What is ΔH in kJ for the process of freezing a 24.7 g sample of liquid chromium at its normal melting point of 1857oC? a. 6.94 kJ b. 9.26 kJ c. 18.9 kJ d. 145 kJ e. 361 kJ ANS: A OBJ: Calculate the amount of energy required to change the phase of a substance. TOP: Enthalpy Changes 154. The following thermochemical equation is for the reaction of ammonia(g) with oxygen(g) to
form nitrogen monoxide(g) and water(g): 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) ΔH = -905 kJ How many grams of NH3(g) would have to react with excess O2(g) to produce 58.6 kJ of energy? Whitten 10e
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a. 15.4 g
b. 3.86 g
c. 61.6 g
d. 0.259 g
e. 4.41 g
ANS: E OBJ: Use stoichiometry to determine the mass of substance required to produce the given energy. TOP: Thermochemical Equations 155. Given the standard enthalpy changes for the following two reactions:
4 C(s) + 5 H2(g) C4H10(g) ΔHo = -125.6 kJ C2H2(g) 2 C(s) + H2(g) ΔHo = 226.7 kJ What is the standard enthalpy change for the reaction: 2 C2H2(g) + 3 H2(g) C4H10(g) ΔHo = ? a. 327.8 kJ b. 101.1 kJ c. 579.0 kJ d. 526.9 kJ
e. -352.3 kJ
ANS: A OBJ: Use Hess's Law to calculate the change in enthalpy. TOP: Hess's Law 156. Using the standard heats of formation given in the table below, calculate the standard enthalpy
change for the following reaction: 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) Compound ΔfHo (kJ/mol) NH3(g) -46.1 NO(g) 90.3 H2O(g) -241.8 a. -905.2 kJ
b. -105.4 kJ
c. -1033.6 kJ
d. -1169.2 kJ
e. -769.6 kJ
ANS: A OBJ: Use the enthalpies of formation to determine the reaction enthalpy. TOP: Standard Molar Enthalpies of Formation, Delta H°f 157. A scientist measures the standard enthalpy change for the following reaction to be -389.6 kJ:
P4O10(s) + 6 H2O(l) 4 H3PO4(aq) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(l) would be: Compound ΔfHo (kJ/mol) P4O10(s) -2984.0 H3PO4(aq) -1288.0 a. b. c. d. e.
-129.1 kJ/mol -296.4 kJ/mol -290.4 kJ/mol -285.8 kJ/mol -241.8 kJ/mol
ANS: B OBJ: Use the balanced thermochemical reaction and enthalpies of formation to calculate the missing enthalpy of formation. TOP: Standard Molar Enthalpies of Formation, Delta H°f
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158. Is the process depicted below endothermic or exothermic?
a. endothermic
b. exothermic
ANS: B OBJ: Classify the pictured change as endothermic or exothermic. TOP: Calorimetry 159. Use average bond enthalpies (given in the table below) to calculate the enthalpy change for
the following gas-phase reaction: CH3OH(g) + HI(g) CH3I(g) + H2O(g) Bond kJ/mol Bond kJ/mol C-H 413 C-O 351 C-C 348 C=O 728 C=C 615 O-H 463 C-I 213 H-I 299 a. 26 kJ
b. -26 kJ
c. 200 kJ
d. 601 kJ
ANS: B OBJ: Calculate the reaction enthalpy using bond enthalpies.
e. -601 kJ
TOP: Bond Energies
160. Use average bond enthalpies (given in the table below) to calculate the enthalpy change for
the following gas-phase reaction: Br2(g) + Cl2(g) 2BrCl(g) Bond kJ/mol Br-Br 193 Cl-Cl 242 Br-Cl 216 a. 3 kJ
b. -3 kJ
c. 219 kJ
d. -219 kJ
e. 652 kJ
ANS: A OBJ: Calculate the reaction enthalpy using bond enthalpies. TOP: Bond Energies CONCEPTUAL 1. Using the First Law of Thermodynamics, describe the energy transformations as a brick is dropped from a ten-story building to the ground below. Show how energy is conserved. OBJ: Describe the energy transformations of a falling brick. TOP: The First Law of Thermodynamics
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2. Gasoline burned in an automobile engine produces work and heat. Gasoline burned in a cooking stove produces only heat. On an equal mass basis, the Es are the same in both cases. Explain. OBJ: Compare the energetics of combustion in an engine to that in a cooking stove. TOP: Changes in Internal Energy, Delta E 3. A growing tree organizes random molecules into complicated ones, creating order. How is this still a spontaneous process? OBJ: Explain spontaneity in terms of a growing tree. TOP: The Two Aspects of Spontaneity 4. Explain how water freezing at 10C can be thermodynamically spontaneous, even though entropy decreases. OBJ: Explain the relationship between temperature and spontaneity TOP: The Temperature Dependence of Spontaneity 5. Thermodynamically, what can be done to make a non-spontaneous reaction spontaneous? How can an endothermic reaction that increases molecular order be made spontaneous? OBJ: Explain how to make a nonspontaneous reaction spontaneous. TOP: The Two Aspects of Spontaneity 6. According to the Second Law of Thermodynamics what would be the ultimate state or condition of the universe? OBJ: Apply the second Law to determine the ultimate state or condition of the universe. TOP: The Second Law of Thermodynamics
Chapter 16—Chemical Kinetics MULTIPLE CHOICE 1. Which of the following is a kinetic quantity? a. enthalpy b. internal energy c. free energy d. rate of reaction e. entropy ANS: D OBJ: Identify the kinetic quantity. TOP: The Rate of a Reaction 2. Of the following questions, which ones are thermodynamic rather than kinetic concepts? I. Can substances react when they are put together? II. If a reaction occurs, how fast will it occur? III. What is the mechanism by which the reaction occurs? IV. If substances react, what energy changes are associated with the reaction? a. I and III b. II and IV Whitten 10e
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c. I and IV d. II and III e. I, III, and IV ANS: C OBJ: Identify the thermodynamic concepts. TOP: The Rate of a Reaction 3. Which of the following expressions does not represent a proper expression for the rate of this reaction? 2A + 3B F + 2G a. b. c. d. e. ANS: A OBJ: Identify the incorrect representation of reaction rate. TOP: The Rate of a Reaction
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4. One of the reactions that is used to produce gaseous hydrogen commercially follows. A proper expression for the rate of this reaction could be ____. H2O(g) + CO(g) H2(g) + CO2(g) a. b. c. k d. e.
ANS: E OBJ: Identify the correct representation of reaction rate. TOP: The Rate of a Reaction 5. In the following reaction, the rate of formation of NH3 is 0.15 mol/Lmin. What is the rate of reaction? N2 + 3H2 2NH3 a. b. c. d. e.
0.15 mol/Lmin 0.075 mol/Lmin 0.075 mol/Lmin 0.20 mol/Lmin 0.30 mol/Lmin
ANS: B OBJ: Calculate the rate of reaction using the balanced equation. TOP: The Rate of a Reaction 6. In the following reaction, time?
a. b. c. d. e.
= 0.89 mol/Ls. What is the value of the rate of the reaction at this
A + 3B AB3
0.30 mol/Ls 0.89 mol/Ls 0.30 mol/Ls 2.67 mol/Ls 0.22 mol/Ls
ANS: A OBJ: Calculate the rate of reaction using the balanced equation. TOP: The Rate of a Reaction
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7. Consider the exothermic combustion of coal. Which of the following could increase the rate of reaction? a. using smaller pieces of coal b. increasing the concentration of oxygen c. lowering the temperature d. both (a) and (b) are correct e. choices (a), (b) and (c) are all correct ANS: D OBJ: Identify the factors that would increase the rate of reaction. TOP: Nature of the Reactants 8. Suppose a reaction A + B C occurs at some initial rate at 25C. Which response includes all of the changes below that could increase the rate of this reaction? I. lowering the temperature II. adding a catalyst III. increasing the initial concentration of B a. b. c. d. e.
I II III I and II II and III
ANS: E OBJ: Identify the factors that would increase the rate of reaction. TOP: Nature of the Reactants 9. Which response below is not an example of how the nature of reactants affects the rate of reaction? a. Graphite burns faster than diamond under equal conditions. b. Coal dust burns faster than large chunks of coal. c. Magnesium reacts faster in higher concentrations of HCl(aq). d. Calcium reacts faster in water than magnesium. e. White phosphorus reacts explosively on contact with air; red phosphorus does not. ANS: C OBJ: Identify the reaction that increases in rate due to a factor other than the nature of the reactants. TOP: Nature of the Reactants 10. Which of the following reactions would be expected to be the slowest? a. Ag+(aq) + Cl(aq) AgCl(s) b. H+(aq) + OH(aq) H2O c. CH4(g) + 2O2(g) CO2(g) + 2H2O(g) d. Pb2+(aq) + CrO42(aq) PbCrO4(s) e. H+(aq) + CN(aq) HCN(aq) ANS: C OBJ: Identify the chemical equation consistent with the slowest reaction. TOP: Nature of the Reactants
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11. Which is not an example of the effect of subdivision of the reactant on the rate of chemical reaction? a. Violent explosions that occur in grain elevators. b. A container of flammable liquid will burn on the surface but allowed to vaporize will burn explosively. c. A chunk of iron takes months to rust completely while iron wool will rust in days. d. Some metals may be fused (welded) with minimal loss while their powders will burn in a flame. e. The Grand Canyon was created by dissolution by water over millions of years. ANS: E OBJ: Identify the reaction that is not an example of the effects of changes in surface area. TOP: Nature of the Reactants 12. For a given reaction, the rate-law expression is ____. a. a constant of proportionality between reaction rate and the concentrations of reactants b. the sum of the powers to which reactant concentrations appear c. an equation in which reaction rate is equal to a mathematical expression involving, or related to, concentrations of reactants involved in the rate-determining step d. an equation that gives the additional energy that reactants must obtain in order to react e. 55 miles per hour ANS: C OBJ: Define rate law expression. TOP: Concentrations of Reactants: The Rate-Law Expression 13. Which of the following statements about reaction orders in the rate law expression is incorrect? a. Their values may equal the stoichiometric coefficients in the balanced equation. b. Their values may or may not equal the stoichiometric coefficients in the balanced equation. c. Their values must be experimentally determined. d. Their values get larger as the temperature is increased. e. An order equal to zero means there is no concentration dependence with rate. ANS: D OBJ: Identify an incorrect description of reaction order. TOP: Concentrations of Reactants: The Rate-Law Expression 14. The gas phase reaction A + B C has a reaction rate which is experimentally observed to follow the relationship rate = k[A][B]2. The overall order of the reaction a. is first. b. is second. c. is third. d. is zero. e. cannot be determined. ANS: C OBJ: Determine the reaction order given the experimental rate law. TOP: Concentrations of Reactants: The Rate-Law Expression
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15. The gas phase reaction A + B + C D has a reaction rate which is experimentally observed to follow the relationship rate = k[A]2[C]. The reaction is ____ order in A, ____ order in B, and ____ order in C. a. first; second; third b. first; second; zero c. second; zero; first d. second; first; zero e. second; zero; zero ANS: C OBJ: Determine the reaction order given the experimental rate law. TOP: Concentrations of Reactants: The Rate-Law Expression 16. The gas phase reaction A + B C has a reaction rate which is experimentally observed to follow the relationship rate = k[A]2[B]. Which one of the following would affect the value of the specific rate constant, k? a. increasing the temperature b. changing the concentration of A c. changing the concentration of B d. changing the concentration of C e. all of these ANS: A OBJ: Identify the factor that affects the rate constant. TOP: Concentrations of Reactants: The Rate-Law Expression 17. A hypothetical reaction X + 2Y Products is found to be first order in X and second order in Y. What are the units of k, the specific rate constant, if reaction rate is expressed in units of moles per liter per second? a. Ms1 b. M2s1 c. M3s d. M2s1 e. M1s ANS: B OBJ: Determine the units of the rate constant. TOP: Concentrations of Reactants: The Rate-Law Expression 18. Which of the following statements regarding the rate constant in the rate law expression is incorrect? a. Its value increases with temperature. b. Its value is independent of initial concentration at a given temperature. c. Its units depend on the overall order of reaction. d. Its value is experimentally determined. e. The larger its value, the slower the reaction rate. ANS: E OBJ: Identify the incorrect description of the rate constant. TOP: Concentrations of Reactants: The Rate-Law Expression
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19. A reaction A + 2B C is found to be first order in A and first order in B. What are the units of the rate constant, k, if the rate is expressed in units of moles per liter per minute? a. M1min1 b. M c. Mmin1 d. min1 e. M2min1 ANS: A OBJ: Determine the units of the rate constant. TOP: Concentrations of Reactants: The Rate-Law Expression 20. Consider the following rate law expression: rate = k[A]2[B]. Which of the following is not true about the reaction having this expression? a. The reaction is first order in B. b. The reaction is overall third order. c. The reaction is second order in A. d. A and B must both be reactants. e. Doubling the concentration of A doubles the rate. ANS: E OBJ: Identify the statement inconsistent with the rate law. TOP: Concentrations of Reactants: The Rate-Law Expression 21. Consider the following rate law expression: rate = k[A][B]2. If the concentration of A is tripled and the concentration of B is reduced by half, what is the resulting change in the reaction rate? a. The rate is increased by 3/2. b. The rate is reduced by 3/4. c. The rate stays the same. d. The rate is doubled. e. The rate is reduced by 1/2. ANS: B OBJ: Determine the factor by which the reaction rate changes. TOP: Concentrations of Reactants: The Rate-Law Expression 22. The gas phase reaction A + B C has a reaction rate which is experimentally observed to follow the relationship rate = k[A]2[B]. If the concentration of A is tripled and the concentration of B is doubled, the reaction rate would be increased by a factor of ____. a. 6 b. 9 c. 12 d. 18 e. 36 ANS: D OBJ: Determine the factor by which the concentration changes. TOP: Concentrations of Reactants: The Rate-Law Expression
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23. The gas-phase reaction 2NO + 2H2 N2 + 2H2O has the following rate law expression, rate = k[NO]2[H2]. If the [NO] is halved and the [H2] is tripled, what change in rate is expected? a. decrease by 3/4 b. increase by 3/4 c. increase by 3/2 d. decrease by 3/2 e. stays same ANS: A OBJ: Determine the factor by which the reaction rate changes. TOP: Concentrations of Reactants: The Rate-Law Expression 24. The gas-phase reaction 2NO + 2H2 N2 + 2H2O has the following rate law expression, rate = 0.14 L2/mol2s[NO]2[H2]. If the [NO] is 0.95 M and the [H2] is 0.45 M, what rate is expected? a. 0.060 mol/Ls b. 0.43 mol/Ls c. 0.027 mol/Ls d. 1.54 mol/Ls e. 0.057 mol/Ls ANS: E OBJ: Determine the rate using the rate expression and reactant concentrations. TOP: Concentrations of Reactants: The Rate-Law Expression 25. A reaction is second order in X and zero order in Y. Doubling the initial concentration of X and halving the initial concentration of Y at constant temperature causes the initial rate to a. increase by a factor of 4. b. decrease by a factor of 2. c. remain unchanged. d. increase by a factor of 2. e. be undeterminable without the balanced equation. ANS: A OBJ: Determine the factor by which the reaction rate changes. TOP: Concentrations of Reactants: The Rate-Law Expression 26. Consider the following rate data for the reaction below at a particular temperature. 2A + 3B Products Experiment 1 2 3
Initial [A] 0.10 M 0.10 M 0.20 M
Initial [B] 0.30 M 0.60 M 0.90 M
Initial Rate of Loss of A 7.20 105 Ms1 1.44 104 Ms1 8.64 104 Ms1
The reaction is ____ order in A and ____ order in B. a. first; first b. second; first c. first; second d. second; second e. third; first Whitten 10e
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ANS: B OBJ: Determine the reaction orders using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 27. Given the following data for the reaction below. NH4+ + NO2 N2 + 2H2O Trial 1 2 3
[NO2] 0.030 M 0.030 0.015
[NH4+] 0.010 M 0.015 0.010
Rate 0.020 M/s 0.030 0.005
The rate law for the reaction is a. rate = k[NH4+][NO2] b. rate = k[NH4+]2[NO2] c. rate = k[NH4+][NO2]2 d. rate = k[NH4+]2[NO2]2 e. None of these ANS: C OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 28. Determine the rate-law expression for the reaction below: 2A + B2 + C B + BC Trial 1 2 3 4 a. b. c. d. e.
Initial [A] 0.20 M 0.40 M 0.20 M 0.20 M
Initial [B2] 0.20 M 0.30 M 0.30 M 0.40 M
Initial [C] 0.20 M 0.20 M 0.20 M 0.40 M
Initial Rate of Formation of BC 2.4 106 Mmin1 9.6 106 Mmin1 2.4 106 Mmin1 4.8 106 Mmin1
rate = k[A]2[B2][C] rate = k[B2]2[C]2 rate = k[A][C]2 rate = k[A]2[C] rate = k[A][B2][C]
ANS: D OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 29. Rate data have been determined at a particular temperature for the overall reaction 2NO + 2H2 N2 + 2H2O in which all reactants and products are gases. Trial Run 1 2 3
Initial [NO] 0.10 M 0.10 M 0.20 M
Initial Rate (Ms1) 0.0150 0.0225 0.0600
Initial [H2] 0.20 M 0.30 M 0.20 M
The rate-law expression is ____.
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a. b. c. d. e.
rate = k[NO]2[H2]2 rate = k[NO][H2]2 rate = k[NO]2[H2] rate = k[NO][H2] None of these is correct.
ANS: C OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 30. A troublesome reaction that is responsible in part for acid rain is SO3 + H2O H2SO4 Rate data have been determined at a particular temperature for the reaction in which all reactants and products are gases. Trial Run 1 2 3 4
Initial [SO3] 0.35 M 0.70 M 0.35 M 0.70 M
Initial Rate (Ms1) 0.150 0.600 0.300 1.20
Initial [H2O] 0.35 M 0.35 M 0.70 M 0.70 M
The rate-law expression is ____. a. rate = k[SO3]2[H2O]2 b. rate = k[SO3]2[H2O] c. rate = k[SO3][H2O]2 d. rate = k[SO3]2 e. rate = k[SO3][H2O] ANS: B OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 31. NO reacts with chlorine in a gas phase reaction to form nitrosyl chloride, NOCl. From the following experimental data, determine the form of the equation that describes the relationship of reaction rate to initial concentrations of reactants. 2NO + Cl2 2NOCl Run 1 2 3 a. b. c. d. e.
Initial [NO] 0.50 M 1.00 M 1.00 M
Initial [Cl2] 0.50 M 1.00 M 0.50 M
Initial Rate of Formation of NOCl 1.14 M/hr 9.12 M/hr 4.56 M/hr
rate = k[NO] rate = k[NO][Cl2] rate = k[NO]2 rate = k[NO]2[Cl2] rate = k[NO]2[Cl2]2
ANS: D OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression
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32. The following data were collected for the following reaction at a particular temperature. What is the rate-law expression for this reaction? rate = ____. A+BC Experiment 1 2 3 a. b. c. d. e.
Initial [A] 0.10 M 0.20 M 0.10 M
Initial [B] 0.10 M 0.20 M 0.20 M
Initial Rate of Formation of C 4.0 104 M/min 3.2 103 M/min 1.6 103 M/min
k[A] k[A]2 k[A][B] k[B] k[A][B]2
ANS: E OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 33. The following data were collected for the following reaction at a particular temperature. What is the rate-law expression for this reaction? rate = ____. NH3 + O2 N2O + H2O Experiment 1 2 3 a. b. c. d. e.
Initial [NH3] 1.10 M 2.20 M 1.10 M
Initial [O2] 1.10 M 2.20 M 2.20 M
Initial Rate 5.5 103 M/s 4.4 102 M/s 2.2 102 M/s
k[NH3] k[NH3]2 k[NH3][O2] k[O2] k[NH3][O2]2
ANS: E OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 34. Determine the rate-law expression for the reaction below at the temperature at which the tabulated initial rate data were obtained. rate = ____ A + 2B + 3C Products Experiment 1 2 3 4 a. b. c. d. e.
Initial [A] 0.10 M 0.40 M 0.20 M 0.20 M
Initial [B] 0.20 M 0.20 M 0.20 M 0.40 M
Initial [C] 0.10 M 0.10 M 0.25 M 0.10 M
Initial Rate of Loss of A 4.0 102 Mmin1 4.0 102 Mmin1 1.0 101 Mmin1 1.6 101 Mmin1
k[A][B] k[A]2[C] k[C]2 k[B]2[C] none of these
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ANS: D OBJ: Determine the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 35. Evaluate the specific rate constant for this reaction at 800C. The rate-law expression is rate = k[NO]2[H2]. (Choose the closest answer.) 2NO(g) + 2H2(g) N2(g) + 2H2O(g) Experiment 1 2 3 a. b. c. d. e.
Initial [NO] 0.0010 M 0.0040 M 0.0040 M
Initial [H2] 0.0060 M 0.0060 M 0.0030 M
Initial Rate of Reaction (Ms1) 7.9 107 1.3 105 6.4 106
22 M2s1 4.6 M2s1 1.3 102 M2s1 0.82 M2s1 0.024 M2s1
ANS: C OBJ: Determine the rate constant using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 36. Evaluate the specific rate constant for the reaction at the temperature for which the data were obtained. The rate-law expression is rate = k[A][B]2. A+BC Experiment 1 2 3 a. b. c. d. e.
Initial [A] 0.10 M 0.20 M 0.10 M
Initial [B] 0.10 M 0.20 M 0.20 M
Initial Rate of Formation of C 4.0 104 M/min 3.2 103 M/min 1.6 103 M/min
1.2 102 M2min1 3.6 102 M2min1 4.0 101 M2min1 6.2 101 M2min1 7.0 103 M2min1
ANS: C OBJ: Determine the rate constant using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 37. Evaluate the specific rate constant at the temperature at which the data were collected. The rate-law expression is rate = k[NO]2[H2]. H2(g) + NO(g) N2O(g) + H2O(g) Experiment 1 2 3
Whitten 10e
Initial [NO] (M) 0.30 0.60 0.60
Initial [H2] (M) 0.35 0.35 0.70
Test Bank
Initial Rate (Ms1) 2.835 103 1.134 102 2.268 102
569
a. b. c. d. e.
9.4 103 M2s1 2.7 102 M2s1 1.6 104 M2s1 8.1 103 M2s1 9.0 102 M2s1
ANS: E OBJ: Determine the rate constant using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 38. Rate data have been determined at a particular temperature for the overall reaction 2NO + 2H2 + 2H2O in which all reactants and products are gases. The value of the specific rate constant at this temperature is ____. Trial Run 1 2 3 a. b. c. d. e.
Initial [NO] 0.10 M 0.10 M 0.20 M
Initial Rate (Ms1) 0.0150 0.0225 0.0600
Initial [H2] 0.20 M 0.30 M 0.20 M
0.75 M1s1 7.5 M2s1 3.0 103 M2s1 3.0 104 M1s1 375 M2s1
ANS: B DIF: Harder Question OBJ: Determine the rate constant using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 39. Consider a chemical reaction involving compounds A and B, which is found to be first order in A and second order in B. At what rate will the reaction occur in experiment 2? Experiment 1 2 a. b. c. d. e.
Rate (Ms1) 0.10 ?
Initial [A] 1.0 M 2.0 M
Initial [B] 0.20 M 0.60 M
1.2 Ms1 0.20 Ms1 0.60 Ms1 1.8 Ms1 0.36 Ms1
ANS: D OBJ: Determine the rate given initial rates data and the rate law. TOP: Concentrations of Reactants: The Rate-Law Expression
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40. The oxidation of NO by O3 is first order in each of the reactants, and its rate constant is 1.5 107 M1s1. If the concentrations of NO and O3 are each 5.0 107 M, what is the rate of oxidation of NO in Ms1? a. 3.8 106 b. 2.5 1014 c. 7.5 107 d. 15 e. 7.5 ANS: A OBJ: Determine the rate using the rate expression and reactant concentrations. TOP: Concentrations of Reactants: The Rate-Law Expression 41. A bimolecular reaction is found to be 1st order with respect to both reactants. If the rate of reaction is 1.87 mol/L s at 25C, what is the reaction rate if both reactant concentrations are doubled? a. 7.48 mol/Ls b. 46.8 mol/Ls c. 1.87 mol/Ls d. 0.94 mol/Ls e. 3.74 mol/Ls ANS: A OBJ: Determine the rate using the rate expression and reactant concentrations. TOP: Concentrations of Reactants: The Rate-Law Expression 42. Consider the hypothetical reaction and rate data below. Determine the form of the rate-law expression (i.e., determine the values of a and b in rate = k[A]a[B]b) and also the value of the specific rate constant, k. Which of the answers below would be the initial rate of reaction for [A]initial = 0.40 M and [B]initial = 0.10 M? 3A + 2B Products
Run 1 2 3 a. b. c. d. e.
[A]initial 0.10 M 0.20 M 0.30 M
Initial Rate of Reaction (moles per liter per second) 4.0 104 4.8 103 3.6 103
[B]initial 0.10 M 0.30 M 0.10 M
1.6 104 Ms1 3.4 103 Ms1 1.2 103 Ms1 4.8 104 Ms1 6.4 103 Ms1
ANS: E DIF: Harder Question OBJ: Determine an initial rate given initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression
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43. Rate data have been determined at a particular temperature for the overall reaction 2NO + 2H2 + 2H2O in which all reactants and products are gases. Trial Run 1 2 3
Initial [NO] 0.10 M 0.10 M 0.20 M
Initial Rate (Ms1) 0.0150 0.0225 0.0600
Initial [H2] 0.20 M 0.30 M 0.20 M
What would be the initial rate of the reaction if the initial molar concentration of NO = 0.30 M and the initial molar concentration of H2 = 0.10 M? a. 0.068 Ms1 b. 0.22 Ms1 c. 0.022 Ms1 d. 0.040 Ms1 e. 0.10 Ms1 ANS: A DIF: Harder Question OBJ: Determine an initial rate given initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression 44. The half-life for the reactant A in the first order reaction below is 36.2 seconds. What is the rate constant for this reaction at the same temperature? A B a. b. c. d. e.
52.2 s1 0.0276 s1 0.0191 s1 18.1 s1 0.00832 s1
ANS: C OBJ: Determine the first order rate constant given half-life. TOP: Concentration Versus Time: The Integrated Rate Equation 45. The rate constant for the first order reaction below is k = 3.3 102 min1 at 57 K. What is the half-life for this reaction at 57 K? A B + C a. b. c. d. e.
21 min 30 min 61 min 9.1 min 1200 min
ANS: A OBJ: Determine the half-life given the first-order rate constant. TOP: Concentration Versus Time: The Integrated Rate Equation
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46. The rate constant for the second order reaction below is 2.79 L/mol min at 48C. If the initial concentration of NO2 is 1.05 M , what is the half-life? 2NO2 N2O4 a. b. c. d. e.
20.5 s 10.3 s 0.341 min 176 s 14.9 s
ANS: B OBJ: Determine the second order half-life. TOP: Concentration Versus Time: The Integrated Rate Equation 47. The half-life of the zero order reaction below is 0.56 minutes. If the initial concentration of A is 3.4 M, what is the rate constant? AB a. b. c. d. e.
6.07 mol/Lmin 1.24 mol/Lmin 3.04 mol/Lmin 0.619 mol/Lmin 1.79 mol/Lmin
ANS: C OBJ: Determine the zero order rate constant given half-life and initial concentration. TOP: Concentration Versus Time: The Integrated Rate Equation 48. The decomposition of dimethylether at 504C is first order with a half-life of 1570. seconds. What fraction of an initial amount of dimethylether remains after 4710. seconds? a. 1/3 b. 1/6 c. 1/8 d. 1/16 e. 1/32 ANS: C OBJ: Use an integrated rate expression to calculate the fraction of reactant remaining. TOP: Concentration Versus Time: The Integrated Rate Equation 49. The decomposition of dinitrogen pentoxide obeys the rate-law expression rate = 0.080 min1[N2O5]. If the initial concentration of N2O5 is 0.30 M, what is the concentration after 2.6 minutes? N2O5 N2O3 + O2 a. b. c. d. e.
0.38 M 0.028 M 0.24 M 0.13 M 0.32 M
ANS: C OBJ: Use an integrated rate expression to calculate the reactant concentration at a later time. TOP: Concentration Versus Time: The Integrated Rate Equation
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50. A molecule of ethyl alcohol is converted to acetaldehyde in one's body by zero order kinetics. If the concentration of alcohol is 0.015 mol/L and the rate constant = 6.4 105 mol/Lmin, what is the concentration of alcohol after 3.5 hours? a. 0.0016 mol/L b. 9.6 107 mol/L c. 4.3 103 mol/L d. 0.15 mol/L e. 0.0032 mol/L ANS: A OBJ: Use an integrated rate expression to calculate the reactant concentration at a later time. TOP: Concentration Versus Time: The Integrated Rate Equation 51. A chemical reaction (below) is first order in A and has a rate constant of 1.2 103 min1. If the initial concentration of A is 0.40 M., how much time must pass in order to reduce the concentration of A to 0.22 M? A B + C a. b. c. d. e.
5.0 102 min 3.0 102 min 7.4 103 min 4.3 104 min 2.2 102 min
ANS: A OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 52. The gas phase reaction below obeys the rate-law expression rate = k[SO2Cl2]. At 593 K the specific rate constant is 2.2 105 s1. A 2.0-g sample of SO2Cl2 is introduced into a closed 4.0-L container. SO2Cl2 SO2 + Cl2 How much time must pass in order to reduce the amount of SO2Cl2 present to 1.8 grams? a. 7.4 103 seconds b. 2.1 102 seconds c. 3.5 102 seconds d. 4.8 103 seconds e. 5.8 104 seconds ANS: D OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant mass to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 53. The gas phase reaction below obeys the rate-law expression rate = k[PCl5]. At 400 K the specific rate constant is 0.0371 min1. How many hours are required to reduce a sample of PCl5 to 10% of its original amount? PCl5 PCl3 + Cl2
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a. b. c. d. e.
3.10 hrs 1.03 hrs 186 hrs 3.71 hrs 62 hrs
ANS: A OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration by a certain percentage. TOP: Concentration Versus Time: The Integrated Rate Equation 54. Consider the following first order reaction. A2B AB + A If it takes 87 seconds for the concentration of A2B to be reduced from 2.2 M to 0.12 M, what is the value of the specific rate constant? a. 0.0334 min1 b. 2.01 min1 c. 2.01 s1 d. 18.3 min1 e. 3.51 103 s1 ANS: B OBJ: Use an integrated rate expression to calculate the rate constant. TOP: Concentration Versus Time: The Integrated Rate Equation 55. The reaction below has the following rate law: rate = 0.011 L/mols [SF4]2. SF4 SF2 + F2 How many minutes will it take for the concentration of SF4 to be reduced from 2.5 M to 0.25 M? a. 327 min b. 0.025 min c. 5.5 min d. 0.040 min e. 22.7 min ANS: C OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 56. Cyclopropane rearranges to form propene in a reaction that is first order. If the rate constant is 2.74 103 s1, how long would it take for 85.6% of the cyclopropane to rearrange if the initial concentration was 0.460 M? a. 51.0 s b. 62.0 s c. 707 s d. 2.74 103 s e. 3.83 104 s
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ANS: C OBJ: Use an integrated rate expression to calculate the time required to change the reactant concentration by a certain percentage. TOP: Concentration Versus Time: The Integrated Rate Equation 57. At 300 K the reaction below obeys the rate law Rate = k[NOCl]2 where k = 2.8 105 M1s1. 2NOCl 2NO + Cl2 Suppose 1.0 mole of NOCl is introduced into a 2.0-liter container at 300 K. Evaluate the half-life of the reaction. a. 2.6 103 seconds b. 3.6 104 seconds c. 2.4 104 seconds d. 1.1 103 seconds e. 4.0 104 seconds ANS: B OBJ: Determine the second order half-life. TOP: Concentration Versus Time: The Integrated Rate Equation 58. The second order reaction below has a rate constant of 5.76 M1min1 at 1600 K. 2CH4 C2H2 + 3H2 How long would it take for the concentration of CH4 to be reduced from 0.89 M to 5.25 104 M? a. 165 hrs b. 0.15 hrs c. 2.75 hrs d. 5.51 hrs e. 9.27 hrs ANS: C OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 59. Compounds A and B react to form C and D in a reaction that is found to be second-order overall and second-order in B. The rate constant at 50.C is 2.48 liter per mole per minute. What is the half-life of B (in min) if 0.822 M B reacts with excess A? A+BC+D a. b. c. d. e.
0.0139 12.0 1.39 0.491 5.88
ANS: D OBJ: Determine the second order half-life. TOP: Concentration Versus Time: The Integrated Rate Equation
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60. At 100 K the reaction below obeys the rate law rate = k[AB2]2 where k = 5.7 M1s1. 2AB2 A2 + 2B2 What would the concentration of AB2 be after 60 minutes if the initial concentration was 1.45 mol/L? a. 4.9 105 M b. 2.0 105 M c. 1.2 102 M d. 2.4 105 M e. 1.9 104 M ANS: D OBJ: Use an integrated rate expression to calculate the reactant concentration at a later time. TOP: Concentration Versus Time: The Integrated Rate Equation 61. At a certain temperature the reaction below obeys the rate-law expression rate = (1.14 103 M1s1)[B]2. If 5.00 mol of B is initially present in a 1.00-L container at that temperature, how long would it take for 2.00 mol of B to be consumed at constant temperature? 2B C + D a. b. c. d. e.
224 s 87.5 s 46.0 s 73.0 s 58.5 s
ANS: E OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 62. Compounds A and B react to form C and D in a reaction that is found to be second-order overall and second-order in B. The rate constant at 30C is 0.622 liter per mole per minute. A+BC+D How many minutes does it take 4.0 102 M B (mixed with excess A) to be reduced to 3.3 102 M B? a. 1.4 min b. 3.6 min c. 5.0 min d. 6.4 min e. 8.5 min ANS: E OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 63. A plot of a. b. c. d. e.
versus time is linear for the reaction D E. What is the kinetic order of the reaction?
second first zero one-half negative one
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ANS: A OBJ: Use graphical date to determine the reaction order. TOP: Concentration Versus Time: The Integrated Rate Equation 64. A plot of ln [C] versus time is linear for the reaction C D. What is the kinetic order of the reaction? a. second b. first c. zero d. one-half e. negative one ANS: B OBJ: Use graphical date to determine the reaction order. TOP: Concentration Versus Time: The Integrated Rate Equation 65. Which statement is incorrect? a. The reaction rate for a zero-order reaction is independent of concentrations. b. The specific rate constant for a zero-order reaction is independent of temperature. c. The half-life for a first-order reaction is independent of initial concentrations. d. The rate law expression relates rate and concentration. e. The integrated rate equation relates time and concentration. ANS: B OBJ: Identify the incorrect description of rate expressions, integrated rate expressions, and half-life. TOP: Concentration Versus Time: The Integrated Rate Equation 66. Which of the following statements concerning graphical methods for determining reaction order is false? a. For a first-order reaction the plot of ln[A] vs. time gives a straight line. b. For a first-order reaction the slope of the straight-line graph equals ak. c. For a second-order reaction the plot of [A]2 vs. time gives a straight line. d. For a first-order reaction the intercept of the straight-line graph equals ln [A]0. e. For a zero-order reaction the plot of [A] vs. time gives a straight line. ANS: C DIF: Harder Question OBJ: Identify the incorrect application of a graphical method in determining reaction order.. TOP: Concentration Versus Time: The Integrated Rate Equation 67. Which idea listed below is not a part of the collision theory of reaction rates? a. Molecules must be properly oriented when they collide to react. b. Molecules must collide to react. c. Molecules must collide with enough kinetic energy to overcome the potential energy stabilization of the bonds. d. Effective collisions result in a chemical reaction. e. All molecular collisions result in a reaction. ANS: E OBJ: Identify the statement that is inconsistent with collision theory. TOP: Collision Theory of Reaction Rates
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68. Which one of the following statements is false? a. In order for a reaction to occur, reactant molecules must collide with each other. b. A catalyst alters the rate of a reaction and is neither a product nor a reactant in the overall equation. c. According to collision theory a three-body collision is less likely than a two-body collision. d. In reactions that are second order in one reactant and first order in another, the slow step generally involves a three-body collision of these reactants. e. The transition state is a short-lived, high energy state, intermediate between reactants and products. ANS: D OBJ: Identify the statement inconsistent with collision theory, the definition of transition state, or the definition of catalyst. TOP: Transition State Theory 69. Which of the following statements regarding collision and transition state theory is false? a. Reactants must collide to form products. b. All reactant collisions result in product formation. c. Activation energy is always positive. d. Reactant molecules must absorb energy to form the transition state. e. Reactant collisions must be oriented properly to form products. ANS: B OBJ: Identify the statement that is inconsistent with collision or transition state theory. TOP: Transition State Theory 70. Which statement is false? a. If a reaction is thermodynamically spontaneous, it may occur rapidly. b. A fast reaction may be thermodynamically spontaneous. c. If a reaction is thermodynamically spontaneous, it may occur slowly. d. If a reaction is thermodynamically spontaneous, it must have a low activation energy. e. Rate of reaction is a kinetic quantity rather than a thermodynamic quantity. ANS: D OBJ: Identify the statement inconsistent with the definition of spontaneous. TOP: Transition State Theory 71. Which term is incorrectly matched with its description? a. Activation Energy / kinetic energy required for reaction to occur b. Transition State / short-lived high-energy intermediate state c. Effective Collision / molecular collision resulting in a reaction d. Net energy change of the reaction / Ea, forward Ea, reverse e. Endothermic Reaction / reaction having Ea, reverse > Ea, forward ANS: E OBJ: Identify the incorrectly matched term and definition. TOP: Transition State Theory
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72. A reaction has an activation energy of 40 kJ and an overall energy change of reaction of 100 kJ. In each of the following potential energy diagrams, the horizontal axis is the reaction coordinate and the vertical axis is potential energy in kJ. Which potential energy diagram best describes this reaction? a.
b.
c.
d.
e.
ANS: A OBJ: Identify the reaction coordinate diagram consistent with the data. TOP: Transition State Theory
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Exhibit 16-1 Given the following potential energy diagram for the one-step reaction X+YZ+R
73. Refer to Exhibit 16-1. The reaction ____. a. releases energy b. absorbs energy c. is impossible d. occurs without a net change in energy e. may either absorb or release energy ANS: A OBJ: Identify the correct interpretation of a reaction coordinate diagram. TOP: Transition State Theory 74. Refer to Exhibit 16-1. The arrow "d" represents the ____. a. energy content of products b. activation energy for the forward reaction c. energy content of reactants d. activation energy for the reverse reaction e. the net change in energy for the reaction ANS: E OBJ: Identify the correct interpretation of a reaction coordinate diagram. TOP: Transition State Theory 75. Refer to Exhibit 16-1. The activation energy of the reverse reaction is equal to ____. a. "d" b. "c" plus "d" c. "c" d. "a" plus "c" e. "d" minus "a" ANS: B OBJ: Identify the correct interpretation of a reaction coordinate diagram. TOP: Transition State Theory 76. Refer to Exhibit 16-1. The arrow "a" represents the ____. a. energy content of products b. activation energy for the forward reaction c. energy content of reactants d. activation energy for the reverse reaction e. the net change in energy for the reaction
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ANS: B OBJ: Identify the correct interpretation of a reaction coordinate diagram. TOP: Transition State Theory 77. Refer to Exhibit 16-1. The point "b" represents ____. a. the energy of the mixture when half of the reactants have been converted to products b. the energy of the transition state c. the number of moles of transition state that must be formed d. the energy of the forward reaction e. the energy of the reverse reaction ANS: B OBJ: Identify the correct interpretation of a reaction coordinate diagram. TOP: Transition State Theory 78. Given the following potential energy diagram for the one-step reaction X+YZ+R
The arrow "c" represents the ____. a. net energy of reaction for the forward reaction b. activation energy for the forward reaction c. net energy of reaction for the reverse reaction d. activation energy for the reverse reaction e. energy content for the reaction ANS: D OBJ: Identify the correct interpretation of a reaction coordinate diagram. TOP: Transition State Theory 79. Which of the following statements about reaction mechanisms is false? a. A reaction can have more than one possible mechanism. b. A reaction mechanism must be consistent with the experimentally observed rate law. c. The slowest step in the reaction mechanism is called the rate-determining step. d. Reaction mechanisms involve complex reaction steps. e. Reaction mechanisms are difficult to prove. ANS: D OBJ: Identify the incorrect description of reaction mechanisms. TOP: Reaction Mechanisms and the Rate-Law Expression
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80. A reaction mechanism will usually be a. the only possible explanation for the reaction. b. difficult to verify experimentally. c. generally obvious from the balanced chemical equation. d. obvious from a consideration of the balanced chemical equation. e. obvious from a consideration of the reaction rate data. ANS: B OBJ: Identify the correct description of reaction mechanisms. TOP: Reaction Mechanisms and the Rate-Law Expression 81. Which of the following is a kinetics concept? a. free energy b. enthalpy c. spontaneity d. reaction mechanism e. entropy ANS: D OBJ: Identify the kinetic quantity. TOP: Reaction Mechanisms and the Rate-Law Expression 82. Consider the hypothetical reaction shown below. A + 2B AB2 Assume that the following proposed mechanism is consistent with the rate data. B B2 B A
+ + + +
B B2 A AB + B AB AB2 2B AB2
slow fast fast overall
Which one of the following statements must be true? The reaction is ____. a. first order in A, second order in B, and third order overall b. second order in B and second order overall c. first order in A and first order overall d. second order in B, zero order in A, and third order overall e. second order in A and second order overall ANS: B OBJ: Use the mechanism to describe the overall reaction rate law. TOP: Reaction Mechanisms and the Rate-Law Expression 83. Consider the hypothetical reaction shown below. 2A + C2 A2C + C Assume that the following proposed mechanism is consistent with the rate data. A AC 2A
+ + +
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C2 AC + C A A2C C2 A2C + C
slow fast overall
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Which one of the following statements must be true? The reaction is ____. a. first order in A, first order in B, and third order overall b. second order in C2 and second order overall c. first order in A and first order in C2 d. second order in C2, zero order in A, and third order overall e. second order in A and second order overall ANS: C OBJ: Use the mechanism to describe the overall reaction rate law. TOP: Reaction Mechanisms and the Rate-Law Expression 84. Consider the following proposed mechanism. If this mechanism for the overall reaction were correct, and if k1 were much less than k2, then the observed rate law would be 2A
C+I
I+B a. b. c. d. e.
C+D
rate = k1[A] rate = k2[I][B] rate = k1[A]2 rate = k1[A]2 k2[C][D] rate = k1k2[A]2[I][B]
ANS: C DIF: Harder Question OBJ: Use the mechanism to determine the overall reaction rate law. TOP: Reaction Mechanisms and the Rate-Law Expression 85. Suppose the reaction 2AB + C2 A2C + B2C occurs by the following mechanism. Step 1 Step 2 Step 3 Step 4 Overall
AB B AC2 A2C2 2 AB
+ + + + +
C2 AC2 AB AB2 AB2 A2C2 B2 A2C C2 A2C
+
B
+ + +
B2 B2C B2C
slow fast fast fast
The rate law expression must be rate = ____. a. k[AB][C2] b. k[AB]2[C2] c. k[AB]2 d. k[AB] e. k[C2] ANS: A OBJ: Use the mechanism to determine the overall reaction rate law. TOP: Reaction Mechanisms and the Rate-Law Expression
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86. Assume the following reaction occurs by the given reaction mechanism. 3H2 + CO CH4 + H2O Step 1 Step 2 Step 3 Overall
H2 H2 H2 3H2
+ + + +
CO H2CO H2CO CH4 O H2O CO CH4
slow fast fast
+O + H2O
The rate law expression must be rate = ____. a. k[H2]2[CO]2 b. k[H2]2[CO] c. k[H2][CO]2 d. k[H2][CO] e. k[H2]2[CO]3 ANS: D OBJ: Use the mechanism to determine the overall reaction rate law. TOP: Reaction Mechanisms and the Rate-Law Expression 87. Consider the reaction below and its observed rate law expression. Which proposed mechanisms are consistent with the rate law expression? rate = k[NO2]2 2NO2 2NO + O2 I.
NO2 + NO2 N2O4 N2O4 N2 + 2O2 N2 + O2 2NO 2NO2 2NO + O2
slow fast fast overall
II.
NO2 N + O2 NO2 + N N2O2 N2O2 2NO 2NO2 2NO + O2
slow fast fast overall
III.
NO2 NO + O O + NO2 NO + O2 2NO2 2NO + O2
slow fast overall
a. b. c. d. e.
I II III I and III another combination
ANS: A OBJ: Identify the mechanisms consistent with the rate law. TOP: Reaction Mechanisms and the Rate-Law Expression 88. Which statement concerning a possible mechanism for a reaction is false? a. A possible mechanism must be consistent with the experimental data. b. Each elementary step is represented by a balanced equation. c. The elementary steps must add to give the equation for the overall reaction. d. The speed of the slow step limits the rate at which the overall reaction occurs. e. The slow step will only include reactants listed in the overall chemical equation. Whitten 10e
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ANS: E OBJ: Identify the statement inconsistent with the description of a mechanism. TOP: Reaction Mechanisms and the Rate-Law Expression 89. Which of the following statements concerning a reaction and its mechanism is false? a. For a reactant, more is consumed than is formed. b. For a product, more is formed than is consumed. c. A reaction intermediate is formed in early steps and completely consumed in later steps. d. For a multi-step mechanism, the slowest step has the highest activation energy. e. Reactions involving simultaneous trimolecular collisions are very common in gases. ANS: E OBJ: Identify the statement inconsistent with the description of a mechanism. TOP: Reaction Mechanisms and the Rate-Law Expression 90. Reaction rates increase with increasing temperature because ____. a. the activation energy increases b. larger molecules collide more frequently c. the energy of the transition state is lowered d. the activation energy is decreased e. a greater fraction of molecules possess the activation energy when they collide ANS: E OBJ: Complete the explanation of the connection between reaction rates and temperature. TOP: Temperature: The Arrhenius Equation 91. Which of the following statements regarding temperature and reaction rate is false. a. The Arrhenius equation can be used to find the activation energy of a reaction. b. Reaction rate always increases with higher temperature. c. A larger negative value of G0 causes a faster reaction rate. d. A larger value of Ea causes a slower reaction rate. e. The rate constant for a reaction decreases at lower temperatures. ANS: C OBJ: Identify the incorrect description of reaction rate, temperature, and the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 92. Suppose the activation energy of a certain reaction is 250 kJ/mol. If the rate constant at T1 = 300 K is k1, and the rate constant at T2 = 320 K is k2, then k2/k1 = ____. (The universal gas constant = 8.314 J/molK.)
a. b. c. d. e.
3 1029 0.067 15.0 525 3 1028
ANS: D OBJ: Calculate the ratio of rate constants using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation
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93. The specific rate constant, k, for a reaction is 2.64 102 s1 at 25C, and the activation energy is 74.0 kJ/mol. Calculate k at 50C. (The universal gas constant = 8.314 J/molK.)
a. b. c. d. e.
0.832 s1 71.9 s1 0.266 s1 1.08 s1 0.0265 s1
ANS: C OBJ: Calculate the missing rate constant using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 94. The specific rate constant, k, for a reaction is 0.44 s1 at 298 K, and the activation energy is 245.kJ/mol. Calculate k at 398 K. (The universal gas constant = 8.314 J/molK.)
a. b. c. d. e.
2.71 1010 s1 6.17 1010 s1 1.03 1010 s1 8.32 108 s1 4.51 109 s1
ANS: A OBJ: Calculate the missing rate constant using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 95. The rate constant for a first-order reaction is 0.58 s1 at 25C. At what temperature would the rate constant have a value of 0.75 s1? The activation energy is 84 kJ/mol and the universal gas constant = 8.314 J/molK.
a. b. c. d. e.
30C 300K 298 K 301 K 310 K
ANS: B OBJ: Calculate the temperature for a given rate constant using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation
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96. The rate constant, k, for a first-order reaction is 1.20 102 s1 at 45C and the activation energy is 98.2 kJ/mol. Calculate the rate constant for this reaction at 95C. a. 1.87 104 s1 b. 7.72 101 s1 c. 6.06 102 s1 d. 1.40 103 s1 e. 2.02 105 s1 ANS: A OBJ: Calculate the missing rate constant using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 97. The rate constant, k, for a first-order reaction is 1.36 103 s1 at 90.C and the activation energy is 78.4 kJ/mol. Calculate the rate constant for this reaction at 50.C. a. 60.4 s1 b. 54.5 s1 c. 23.8 s1 d. 4.85 s1 e. 1.78 103 s1 ANS: B OBJ: Calculate the missing rate constant using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 98. Calculate the activation energy of a reaction if the rate constant is 0.75 s1 at 25C and 11.5 s1 at 75C. a. 681 J/mol b. 20.4 kJ/mol c. 15.8 kJ/mol d. 47.1 kJ/mol e. 31.4 kJ/mol ANS: D OBJ: Calculate the activation energy using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 99. Calculate the activation energy of a reaction if its rate constant is 2.8 106 s1 at 24C and 1.5 107 s1 at 48C. a. 26 kJ/mol b. 80. kJ/mol c. 55 kJ/mol d. 67 J/mol e. 3.51 J/mol ANS: C OBJ: Calculate the activation energy using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation
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100. What would be the activation energy of a reaction if its rate constant at 35C was double the value of its rate constant at 25C? a. 63.8 kJ/mol b. 75.1 kJ/mol c. 8.12 kJ/mol d. 52.9 kJ/mol e. 68.3 J/mol ANS: D OBJ: Calculate the activation energy using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 101. A catalyst ____. a. is used up in a chemical reaction b. changes the value of G0 of the reaction c. is always a solid d. does not influence the reaction in any way e. changes the activation energy of the reaction ANS: E OBJ: Define catalyst. TOP: Catalysts 102. A catalyst a. increases the amount of products present at equilibrium. b. increases the rate at which equilibrium is reached but decreases the equilibrium constant. c. increases the rate at which equilibrium is reached without changing the equilibrium constant. d. increases H for the process. e. lowers S for the process. ANS: C OBJ: Define catalyst. TOP: Catalysts 103. Which of the following statements about catalysts are false? a. A catalyst lowers the activation energy. b. A catalyst can make a nonspontaneous reaction spontaneous. c. A catalyst speeds up both the forward and reverse reaction. d. A catalyst speeds up the rate of reaction. e. Catalyst are often transition metals and transition metal oxides. ANS: B OBJ: Identify the statement that is inconsistent with the term catalyst. TOP: Catalysts 104. Which of the following is not an example of an important, useful reaction catalyzed by transition metals and/or their oxides? a. the Haber process for the production of ammonia b. the contact process for the production of sulfur trioxide in producing sulfuric acid c. the hydrogenation of unsaturated hydrocarbons d. the reaction of leaded fuels with the catalysts in catalytic converters e. the chlorination of benzene
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ANS: D OBJ: Identify the unimportant reaction. TOP: Catalysts 105. The catalytic converters installed in newer models of automobiles are designed to catalyze certain kinds of favorable reactions. Unfortunately, other unfavorable reactions also are catalyzed. Which one of those listed below, all of which are catalyzed in such mufflers, is an unfavorable reaction? a. 2CO(g) + O2(g) 2CO2(g) b. 2C8H18(g) + 25O2(g) 16CO2(g) + 18H2O(g) c. C(s) + O2(g) CO2(g) d. 2SO2(g) + O2(g) 2SO3(g) e. 2NO(g) N2(g) + O2(g) ANS: D OBJ: Identify the chemical equation of an unfavorable reaction catalyzed by a catalytic converter. TOP: Catalysts 106. Which statement concerning biological catalysts is false? a. Enzymes are proteins that act as catalysts for specific biochemical reactions. b. The reactants in enzyme-catalyzed reactions are called substrates. c. Each enzyme catalyzes many different reactions in a living system. d. Enzyme-catalyzed reactions are important examples of zero-order reactions. e. Discovery or synthesis of catalysts that mimic the efficiency of naturally occurring enzymes would saved on the costs of using high temperature and high pressure in commercial processes. ANS: C OBJ: Identify the statement inconsistent with the description of an enzyme. TOP: Catalysts 107. The reaction, A + 2B B2 + A, proceeds by the following mechanism: (A is a catalyst.) (slow) A + B AB (fast) AB + B B2 + A What is the rate law expression for this reaction? a. Rate = k[A] b. Rate = k[B] c. Rate = k[A][B] d. Rate = k[A][B]2 e. Rate = k[A]2[B] ANS: C OBJ: Use the mechanism to determine the overall reaction rate law. TOP: Catalysts 108. Which of the following is/are expected to affect the rate of a chemical reaction? 1. 2. 3.
Increasing the reaction temperature. Addition of a catalyst. Stirring a well mixed reaction solution.
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a. b. c. d. e.
1 only 2 only 3 only 1 and 2 1, 2, and 3
ANS: D DIF: easy OBJ: Identify the factors that affect the rate of a reaction. TOP: Nature of the Reactants | Catalysts 109. For which of the following hypothetical rate laws would the units of the rate constant have the general form Mtime? a. rate = k b. rate = k[A] c. rate = k[A]3 d. rate = k[A]2 e. rate = k[A]4 ANS: A DIF: easy OBJ: Identify the rate law consistent with the given units of the rate constant. TOP: Concentrations of Reactants: The Rate-Law Expression 110. For a certain third-order reaction with the general form aA products, the rate is 0.36 M·s when the concentration of the reactant is 0.35 mol/L. What is the rate constant for this reaction? a. b. c. d. e.
0.042 Ms 8.4 Ms 0.36 Ms 0.34 Ms 24 Ms
ANS: B DIF: easy OBJ: Determine the rate constant given the reaction order, rate, and reactant concentration. TOP: Concentrations of Reactants: The Rate-Law Expression 111. If a reaction is second-order with respect to a particular reactant, when the concentration of that reactant is increased by a factor of 2, the reaction rate will _____. a. increase by a factor of 4. b. remain constant. c. 1 decrease by a factor of . 4 d. increase by a factor of 2. e. 1 decrease by a factor of . 8
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ANS: A DIF: easy OBJ: Determine the change in the rate given the change in a reactant concentration and the order with respect to the reactant. TOP: Concentrations of Reactants: The Rate-Law Expression 112. A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant. If the rate constant is 3.6 10–2 L/(mol · s), what is the time required to decrease the initial concentration to 0.050 mol/L? a. 280 s b. 420 s c. 19.3 s d. 1.39 s e. 830 s ANS: A DIF: easy OBJ: Use an integrated rate expression to calculate the time required to reduce the reactant concentration to a certain value. TOP: Concentration Versus Time: The Integrated Rate Equation 113. A first-order chemical reaction is observed to have a rate constant of 25 min–1. What is the corresponding half-life for the reaction? a. 1.7 s b. 1.7 min c. 36 min d. 2.4 s e. 35.8 s ANS: A DIF: easy OBJ: Calculate the half-life given the reaction order and rate constant. TOP: Concentration Versus Time: The Integrated Rate Equation 114. For a certain reaction of the general form aA products, a plot of the experimental data as 1/[A] versus time is linear. What is the reaction order with respect to reactant A? a. second b. zero c. first d. fourth e. third ANS: A DIF: easy OBJ: Identify the order with respect to a reactant given the graphical data. TOP: Concentration Versus Time: The Integrated Rate Equation
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115. For the hypothetical reaction aA products, the experimental data showed the following behavior (below). What is the reaction order with respect to reactant A?
a. b. c. d. e.
zero order first order second order third order fourth order
ANS: A DIF: moderate OBJ: Identify the order with respect to a reactant given the graphical data. TOP: Concentration Versus Time: The Integrated Rate Equation 116. The rate constant for a reaction at 40.0°C is exactly 4 times that at 20.0°C. Calculate the Arrhenius energy of activation for the reaction. a. 4.00 kJ/mol b. 6.36 kJ/mol c. 52.8 kJ/mol d. 11.5 kJ/mol e. none of these ANS: C DIF: moderate OBJ: Calculate the energy of activation using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 117. The rate constant for a first-order reaction is 1.4 10–2 s–1 at 716 K and 5.5 10–2 s–1 at 864 K. What is the activation energy? a. 27 kJ/mol b. 21 kJ/mol c. 47 kJ/mol d. 5700 kJ/mol e. 48 kJ/mol ANS: E DIF: easy OBJ: Calculate the activation energy using the Arrhenius equation. TOP: Temperature: The Arrhenius Equation 118. For a certain reaction, a plot of reactant concentration as a function of time gave a straight
line. What is the order of this reaction? a. Zero order b. First order c. Second order d. Pseudo-first order e. Impossible to tell from the given information Whitten 10e
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ANS: A OBJ: Identify the order with respect to a reactant given the graphical data. TOP: Concentration Versus Time: The Integrated Rate Equation 119. For a reaction to take place, the molecules that are reacting ______. a. must have more energy than the products b. must have less energy than the products c. must be able to reach the activation energy d. must be in considerable numbers ANS: C OBJ: Understand the tenets of collision theory. TOP: Collision Theory of Reaction Rates 120. In a reaction coordinate diagram, reacting molecules are most unstable ______. a. at their initial position c. right after they collide b. when they are about to collide d. at the transition state ANS: D OBJ: Describe a reaction coordinate diagram. TOP: Temperature: The Arrhenius Equation 121. If the half-life of a reaction is independent of concentration, the reaction is: a. Zero order b. First order c. Second order d. Zero and first order e. First and second order ANS: A OBJ: Identify the rate law which has a half-life independent of concentration. TOP: Concentration Versus Time: The Integrated Rate Equation 122. For the gas phase decomposition of dinitrogen pentoxide at 335K: 2 N2O5 4NO2 + O2
The average rate of disappearance of N2O5 over the time period from t = 0s to t = 114s is found to be 5.02 x 10-4 M s-1. The average rate of formation of NO2 over the same time period is: a. 2.51 x 10-4 Ms-1 b. 5.02 x 10-4 Ms-1 c. 2.01 x 10-3 Ms-1 d. 1.00 x 10-3 Ms-1 e. 1.99 x 10-1 Ms-1 ANS: D OBJ: Calculate the average rate of product formation given the average rate of disappearance and the balanced reaction. TOP: The Rate of a Reaction
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123. The reaction of ICl with hydrogen : 2 ICl + H2 I2 + 2 HCl
is first order in ICl and second order in H2. In an experiment to determine the rate law, the rate constant was determined to be 2.24 M-2s-1. Using this value for the rate constant, the rate of the reaction when [ICl] = 0.314M and [H2] = 0.179M would be: a. 1.26 x 10-3 Ms-1 b. 2.25 x 10-2 Ms-1 c. 3.95 x 10-2 Ms-1 d. 2.23 x 102 Ms-1 e. 2.52 x 10-1 Ms-1 ANS: B OBJ: Calculate the rate of reaction given the reactant orders and concentrations. TOP: Concentration Versus Time: The Integrated Rate Equation
Use the initial rate data below to answer the following questions: The following initial rate data are for the reaction of hypochlorite ion with iodide ion in 1M aqueous hydroxide solution: OCl- + I- OI- + ClExperiment [OCl-] [I-] Rate -3 -3 1 3.48 x 10 5.05 x 10 1.34 x 10-3 2 3.48 x 10-3 1.01 x 10-2 2.68 x 10-3 3 6.97 x 10-3 5.05 x 10-3 2.68 x 10-3 -3 -2 4 6.97 x 10 1.01 x 10 5.36 x 10-3 124. What is the rate law for this reaction? a. Rate = k[OCl-] b. Rate = k[I-] c. Rate = k[OCl-][I-] d. Rate = k[OCl-]2[I-] e. Rate = k[OCl-][I-]2 ANS: C OBJ: Calculate the rate law using initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression -
-
125. What is the rate of the above reaction when [OCl ] = 0.224M and [I ] = 0.125M? a. 0.267 Ms-1 b. 0.367 Ms-1 c. 0.478 Ms-1 d. 2.13 Ms-1 e. 17.1 Ms-1 ANS: D OBJ: Calculate an initial rate for other initial rates data. TOP: Concentrations of Reactants: The Rate-Law Expression o
126. The gas phase decomposition of dimethyl ether at 500 C
CH3OCH3(g) CH4(g) + H2(g) + CO)g) is first order in CH3OCH3 with a rate constant of 4.00 x 10-4 s-1. If an experiment is performed in which the initial concentration of CH3OCH3 is 4.56 x 10-2M, what is the concentration of CH3OCH3 after 4879 s have passed? a. 0.00539 M b. 0.00648 M c. 0.0149 M d. 0.0191 M e. 0.0321 M ANS: B OBJ: Calculate the concentration of reactant using the concentration-time expression. TOP: Concentration Versus Time: The Integrated Rate Equation Whitten 10e
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Use the information below to answer the following questions: The concentration of A was found as a function of time during the course of the reaction: A C, and the data was graphed several different ways: Time, s 0 1 2 3 4 5 6 7 8
[A], mol/L 0.9101 0.1893 0.1056 0.07327 0.05608 0.04542 0.03817 0.03291 0.02893
127. Using the information above, what is the order of the reaction? a. Zero order b. First order c. Second order d. Third order e. Pseudo-first order ANS: C OBJ: Determine the reaction order from various graphs of the data. TOP: Concentration Versus Time: The Integrated Rate Equation 128. What is the value of the rate constant, k, for the above reaction? a. 0.431 b. 0.441 c. 0.455 d. 4.18
e. 4.46
ANS: D OBJ: Extract the rate constant from graphical reaction kinetics data. TOP: Concentration Versus Time: The Integrated Rate Equation
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129. The mechanism below has been proposed for the hydrolysis of methyl acetate:
Which species in the above reaction mechanism is acting as a catalyst? a. H2O b. H3O+ c.
d. e.
ANS: B OBJ: Identify the catalyst given the reaction mechanism. TOP: Reaction Mechanisms and the Rate-Law Expression 130. For the gas phase decomposition of ethyl chloroformate, ClCOOC2H5 C2H5Cl + CO2
The rate constant has been determined at several different temperatures. When the data is graphed as ln k vs. 1/T, the slope of the line is -1.48 x 104 and the y-intercept is 24.6. What is the activation energy, Ea, for this reaction? a. 9.62 kJ b. 15.0 kJ c. 123 kJ d. 205 kJ e. 1214 kJ ANS: C OBJ: Use the Arrhenius equation to determine the energy of activation. TOP: Temperature: The Arrhenius Equation
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CONCEPTUAL 1. What is implied if a reactant has a negative reaction order in the rate law expression? Are fractional orders possible? OBJ: Discuss the implications of a negative reaction order and the possibility of fractional reaction orders. TOP: Concentrations of Reactants: The Rate-Law Expression 2. Describe the concept of a transition state. Why can't we collect and study transition state species? What observations about the transition state lead us to conclude that it is unstable? OBJ: Discuss the idea of a transition state. TOP: Transition State Theory 3. Propose a 3-step mechanism for the following reaction, which shows 1st order dependence for both H2 and CO. 3H2 + CO CH4 + H2O OBJ: Propose a mechanism consistent with the given parameters. TOP: Reaction Mechanisms and the Rate-Law Expression 4. Monoatomic chlorine is a catalyst in the decomposition of ozone, O3. Explain how a single chlorine atom is capable of decomposing thousands of O3 molecules. OBJ: Describe the function of a catalyst. TOP: Catalysts 5. Considering the effect of temperature and reaction rate, discuss why enzymes are so important for the function of living organisms. OBJ: Explain the importance of enzymes in living organisms given the correlation between temperature and reaction rate. TOP: Temperature: The Arrhenius Equation | Catalysts 6. When vinegar (5% acetic acid) is added to solid baking soda (sodium hydrogen carbonate), they react to produce sodium acetate, water, and carbon dioxide gas: CH3COOH(aq) + NaHCO3(s) NaCH3COO(aq) + H2O + CO2(g) List four ways the rate of this reaction can be increased OBJ: List four specific ways to increase the rate of a reaction. TOP: Nature of the Reactants
Chapter 17: Advanced Acid-Base Equilibria MULTIPLE CHOICE 1. Which of the statements concerning equilibrium is false? a. A system that is disturbed from an equilibrium condition responds in a manner to restore equilibrium. b. Equilibrium in molecular systems is dynamic, with two opposing processes balancing one another. c. The value of the equilibrium constant for a given reaction mixture is the same regardless Whitten 10e
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of the direction from which equilibrium was attained. d. A system moves spontaneously toward a state of equilibrium. e. The equilibrium constant usually is independent of temperature. ANS: E OBJ: Identify the statement inconsistent with the definition of equilibrium. TOP: Chapter 17 Basic Concepts 2. Which of the following is the best definition of chemical equilibrium? a. A condition where the forward and reverse reaction rates of a reversible reaction are equal and constant. b. There are equal amounts of reactants and products. c. The forward and reverse reaction rates have stopped. d. The product concentrations are larger than reactant concentrations. e. The reactant concentrations are larger than product concentrations. ANS: A OBJ: Define equilibrium. TOP: Chapter 17 Basic Concepts 3. When the system A + B C + D is at equilibrium, a. the forward reaction has stopped. b. the reverse reaction has stopped. c. both the forward and the reverse reactions have stopped. d. neither the forward nor the reverse reaction has stopped. e. the sum of the concentrations of A and B must equal the sum of the concentrations of C and D. ANS: D OBJ: Identify the correct description of a system at equilibrium. TOP: Chapter 17 Basic Concepts
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4. Consider the gas phase system below at a high temperature. The form of the expression for the equilibrium constant, Kc, ____. 4NH3 + 5O2 4NO + 6H2O a. cannot be determined without rate data b. is c. is d. is e. is ANS: E OBJ: Determine the equilibrium expression given the balanced reaction. TOP: The Equilibrium Constant 5. Consider the following reaction. What would be the equilibrium constant expression? 4Br2(g) + CH4(g) 4HBr(g) + CBr4(g) a. b.
c.
d. e.
ANS: C OBJ: Determine the equilibrium expression given the balanced reaction. TOP: The Equilibrium Constant
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6. Consider the following reaction. What would be the equilibrium constant expression? CH4(g) + H2O(g) CO(g) + 3H2(g) a.
b.
c.
d. e.
ANS: B OBJ: Determine the equilibrium expression given the balanced reaction. TOP: The Equilibrium Constant 7. Consider the following reaction involving a solid. 3Fe(s) + 4H2O(g) Fe3O4(s) + 4H2(g) The appropriate equilibrium constant expression would be: a.
b.
c. d.
e.
ANS: B OBJ: Determine the equilibrium expression given the balanced reaction. TOP: The Equilibrium Constant
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8. What is the equilibrium constant expression for the following reaction? C3H8(g) + 5O2(g) 3CO2(g) + 4H2O a. b. c.
d.
e.
ANS: D OBJ: Determine the equilibrium expression given the balanced reaction. TOP: The Equilibrium Constant 9. What is the equilibrium constant expression for the following reaction? 2NO2(g) N2O4(g) a. b.
c.
d. e. Kc = [NO2]2 ANS: B OBJ: Determine the equilibrium expression given the balanced reaction. TOP: The Equilibrium Constant 10. For a reversible reaction with a one-step mechanism, A B , the rate of the forward reaction is ratef = 3.2 106 s1 [A] and the rate of the reverse reaction is rater = 4.6 104 s1 [B]. What is the value of Kc for this reaction? a. 2.5 1011 b. 7.0 109 c. 7.0 103 d. 1.4 102 e. 1.5 109 Whitten 10e
Test Bank
602
ANS: C OBJ: Calculate K given the forward and reverse reaction rates. TOP: The Equilibrium Constant 11. What is the value of Kc for the reaction below if at equilibrium [A] = 0.60 M, [B] = 0.30 M, [C] = 0.10 M and [D] = 0.50 M? 2A(g) + 3B(g) 2C(g) + D(g) a. b. c. d. e.
1.9 0.15 2.4 0.51 0.088
ANS: D OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant 12. What is the value of Kc for the reaction below if at equilibrium [CH4] = 0.20 M, [H2O] = 0.20 M, [CO] = 0.50 M and [H2] = 1.50 M? CH4(g) + H2O(g) CO(g) + 3H2(g) a. b. c. d. e.
19 0.24 0.053 42 16
ANS: D OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant 13. In a 1.0-liter container there are, at equilibrium, 0.20 mole of I2, 0.30 mole of H2, and 0.20 mole of HI. What is the value of Kc for the reaction? H2(g) + I2(g) 2HI(g) a. b. c. d. e.
0.33 0.67 2.7 1.3 1.5
ANS: B OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant 14. In a 1.0-liter container there are, at equilibrium, 0.10 mole H2, 0.20 mole N2, and 0.40 mole NH3. What is the value of Kc for this reaction at this temperature? N2(g) + 3H2(g) 2NH3(g) a. b. c. d. e.
0.0012 20 8.0 102 0.050 8.0
Whitten 10e
Test Bank
603
ANS: C OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant 15. Consider the formation of ammonia from nitrogen and hydrogen: N2(g) + 3H2(g) 2NH3(g) A reaction is initiated with 0.50 M of both N2 and H2 and no NH3. At equilibrium, the concentration of NH3 was 0.25 M. What is the value of Kc? a. 5.3 b. 0.012 c. 85 d. 16 e. 1.0 ANS: C OBJ: Calculate K from initial and equilibrium concentrations. TOP: The Equilibrium Constant 16. Consider the following reversible reaction. In a 3.00-liter container, the following amounts are found in equilibrium at 400C: 0.0420 mole N2, 0.516 mole H2, and 0.0357 mole NH3. Evaluate Kc. N2(g) + 3H2(g) 2NH3(g) a. b. c. d. e.
0.202 1.99 16.0 4.94 0.503
ANS: B OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant 17. Nitrogen oxide and bromine combine to form nitrosyl bromide, NOBr. 2NO(g) + Br2(g) 2NOBr(g) In a 5.0 liter reactor at equilibrium at a constant temperature, it was determined there was 0.45 mol NO, 0.17 mol Br and 1.32 mol NOBr. What is the value of Kc at this temperature? a. 0.0116 b. 86.2 c. 253 d. 0.00395 e. 22.7 ANS: C OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant
Whitten 10e
Test Bank
604
18. At equilibrium, the following amounts are found at a certain temperature in a 3.0-liter container: 2.0 mole of Cl2, 0.80 mol of H2O (steam), 0.0030 mol of HCl, and 0.0045 mol of O2. Evaluate Kc at that temperature. 2Cl2(g) + 2H2O(g) 4HCl(g) + O2(g) a. b. c. d. e.
4.7 1014 8.4 107 1.4 1013 2.2 1013 7.1 1012
ANS: A OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: The Equilibrium Constant 19. Consider the reaction 2NO2(g)
N2O4(g)
A reaction is initiated at 100C with 2.35 moles NO2 in a 3.0 L reactor (no N2O4 present). If the equilibrium concentration of N2O4 is 0.25 M, what is the value of Kc at 100C? a. 0.25 b. 0.31 c. 3.2 d. 6.7 e. 0.15 ANS: C OBJ: Calculate K from initial and equilibrium concentrations. TOP: The Equilibrium Constant 20. Consider the following reaction in which all reactants and products are gases. 1.00 mol of A and 2.00 mol of B are placed in a 5.0-liter container. After equilibrium has been established, 0.50 mol of D is present in the container. Calculate the equilibrium constant, Kc, for the reaction. A + 2B 2C + D a. b. c. d. e.
1.0 0.15 0.33 3.0 5.0
ANS: A DIF: Harder Question OBJ: Calculate K from initial and equilibrium concentrations. TOP: The Equilibrium Constant
Whitten 10e
Test Bank
605
21. Given: A(g) + 3B(g)
C(g) + 2D(g)
One (1.0) mole of A and 1.0 mole of B are placed in a 5.0-liter container. After equilibrium has been established, 0.50 mole of D is present in the container. Calculate the equilibrium constant, Kc, for the reaction. a. 1.2 b. 0.68 c. 12 d. 27 e. 1.4 102 ANS: D DIF: Harder Question OBJ: Calculate K from initial and equilibrium concentrations. TOP: The Equilibrium Constant 22. The equilibrium constant for the reaction below is 26 at 50C. CO(g) + H2O(g) CO2(g) + H2(g) What is Kc for 3CO2(g) + 3H2(g) at the same temperature? a. 0.34 b. 1.8 104 c. 0.038 d. 5.7 105 e. 2.9
3CO(g) + 3H2O(g)
ANS: D OBJ: Calculate K given a different reaction stoichiometry. TOP: Variation of Kc with the Form of the Balanced Equation 23. Given the following reaction and its equilibrium constant at a certain temperature: N2(g) + 3H2(g) 2NH3(g) Kc = 3.6 108 Calculate the numerical value of the equilibrium constant for the following reaction at the same temperature. NH3(g) a. b. c. d. e.
N2(g) + H2(g)
2.8 109 1.9 104 1.3 107 5.3 105 7.7 1018
ANS: D OBJ: Calculate K given a different reaction stoichiometry. TOP: Variation of Kc with the Form of the Balanced Equation
Whitten 10e
Test Bank
606
24. If the equilibrium constant at a certain temperature is 2.1 1013 for the following reaction, 4HCl(g) + O2(g) 2Cl2(g) + 2H2O(g) calculate the value of the equilibrium constant at the same temperature for Cl2(g) + H2O(g) a. b. c. d. e.
HCl(g) + O2(g)
2.2 107 3.8 103 5.3 1012 4.7 104 1.2 1014
ANS: D OBJ: Calculate K given a different reaction stoichiometry. TOP: Variation of Kc with the Form of the Balanced Equation 25. Which of the following statements about the reaction quotient, Q, is false? a. The value of Q can be used to predict equilibrium concentrations. b. It has the same expression as Kc. c. Its value is calculated using nonequilibrium concentrations. d. If Q > Kc, the reaction must move to equilibrium by forming more reactants. e. If Q < Kc, the reaction must move to equilibrium by forming more products. ANS: A OBJ: Identify an incorrect description of Q. TOP: The Reaction Quotient 26. The equilibrium constant for the following gas phase reaction is 0.50 at 600C. A mixture of HCHO, H2, and CO is introduced into a flask at 600C. After a short time, analysis of a small amount of the reaction mixture shows the concentrations to be [HCHO] = 1.5 M, [H2] = 0.5 M, and [CO] = 1.0 M. Which of the following statements about this reaction mixture is true? HCHO H2 + CO a. The reaction mixture is at equilibrium. b. The reaction mixture is not at equilibrium, but no further reaction will occur. c. The reaction mixture is not at equilibrium, but will move toward equilibrium by forming more HCHO. d. The reaction mixture is not at equilibrium, but will move toward equilibrium by using up more HCHO. e. The forward rate of this reaction is the same as the reverse rate. ANS: D OBJ: Use the reaction quotient to define the status of a reaction. TOP: The Reaction Quotient
Whitten 10e
Test Bank
607
27. The following reaction is initiated and the concentrations are measured after ten minutes: A(g) + 3 B(g) AB3(g) Kc = 1.33 102 [A] = 1.78 M [B] = 2.21 M [AB3] = 1.19 M Is the reaction in equilibrium? a. Yes. b. No, because Q < K. c. No, and the [AB3] must increase to establish equilibrium. d. No, because Q > K. e. There is no way to tell. ANS: D OBJ: Use the reaction quotient to define the status of a reaction. TOP: The Reaction Quotient 28. The equilibrium constant, Kc, for the following reaction is 0.0154 at a high temperature. A mixture in a container at this temperature has the concentrations: [H2] = 1.11 M, [I2] = 1.30 M and [HI] = 0.181 M. Which of the following statements concerning the reaction and the reaction quotient, Q, is true? H2(g) + I2(g) 2HI(g) a. b. c. d. e.
Q = Kc Q > Kc; more HI will be produced. Q > Kc; more H2 and I2 will be produced. Q < Kc; more HI will be produced. Q < Kc; more H2 and I2 will be produced.
ANS: C OBJ: Use the reaction quotient to define the status of a reaction. TOP: The Reaction Quotient 29. At a certain temperature Kc = 25 and a reaction vessel contains a mixture with the following concentrations: [H2] = 0.10 M, [Br2] = 0.10 M and [HBr] = 0.50 M. Which of the following statements concerning the reaction and the reaction quotient, Q, is true? H2(g) + Br2(g) 2HBr(g) a. b. c. d. e.
Q = Kc Q < Kc; more HBr will be produced. Q < Kc; more H2 and Br2 will be produced. Q > Kc; more HBr will be produced. Q > Kc; more H2 and Br2 will be produced.
ANS: A OBJ: Use the reaction quotient to define the status of a reaction. TOP: The Reaction Quotient 30. At a certain temperature Kc = 55 and a reaction vessel contains a mixture with the following concentrations: [SO3] = 0.85 M, [NO] = 1.2 M , [SO2] = 1.5 M and [NO2] = 2.0 M. Which of the following statements concerning the reaction and the reaction quotient, Q, is false? SO3(g) + NO(g) SO2(g) + NO2(g) a. b. c. d. e.
Q < Kc Q > Kc The reaction is not in equilibrium. Product concentrations will increase as equilibrium is approached. Reactant concentrations will decrease as equilibrium is approached.
Whitten 10e
Test Bank
608
ANS: B OBJ: Use the reaction quotient to define the status of a reaction. TOP: The Reaction Quotient 31. Nitrosyl chloride, NOCl, dissociates on heating as shown below. When a 1.50-gram sample of pure NOCl is heated at 350C in a volume of 1.00 liter, the percent dissociation is found to be 57.2%. Calculate the equilibrium concentration of NOCl. NOCl(g) a. b. c. d. e.
NO(g) + Cl2(g)
8.76 101 M 9.26 M 9.80 103 M 1.31 102 M 1.75 104 M
ANS: C DIF: Harder Question OBJ: Determine the product equilibrium concentration given the percent dissociation. TOP: Uses of the Equilibrium Constant, Kc 32. The numerical value of the equilibrium constant, Kc, for the following gas phase reaction is 0.50 at a certain temperature. When a certain reaction mixture reaches equilibrium, the concentration of O2 is found to be 2.0 M, while the concentration of SO3 is found to be 10 M. What is the equilibrium concentration of SO2 in this mixture? 2SO2 + O2 2SO3 a. b. c. d. e.
0.50 M 10 M 0.10 M 5.0 M 1.0 M
ANS: B OBJ: Determine the missing equilibrium concentration. TOP: Uses of the Equilibrium Constant, Kc 33. For the reaction below the value of the equilibrium constant is 0.0187 at a particular temperature. 3O2 2O3 If the equilibrium concentration of [O2] is 0.75 M, what is the equilibrium concentration of O3? a. 0.089 M b. 0.22 M c. 0.75 M d. 0.0079 M e. 0.014 M ANS: A OBJ: Determine the missing equilibrium concentration. TOP: Uses of the Equilibrium Constant, Kc
Whitten 10e
Test Bank
609
34. Consider the following system. The equilibrium constant for the reaction at 900C is 0.082. A reaction is initiated with only COCl2 in a 2.0-liter vessel. At equilibrium 2.36 103 mol of Cl2 is present. How many moles of COCl2 are present at equilibrium? COCl2(g) CO(g) + Cl2(g) a. b. c. d. e.
1.4 104 mol 1.4 103 mol 6.1 105 mol 5.8 104 mol 3.4 105 mol
ANS: E DIF: Harder Question OBJ: Determine the missing equilibrium concentration. TOP: Uses of the Equilibrium Constant, Kc 35. The Kc for the following reaction is 5.62 at 305C. A2(g) + B2(g) 2 C(g) If a reaction is initiated with 2.4 M of each substance, what is the equilibrium concentration of C? a. 0.76 M b. 5.3 M c. 4.3 M d. 1.2 M e. 2.4 M ANS: B OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 36. A quantity of HI was sealed in a tube, heated to 425C, and held at this temperature until equilibrium was reached. The concentration of HI in the tube at equilibrium was found to be 0.0706 moles/liter. Calculate the equilibrium concentration of H2 (and I2) for the reaction: H2(g) + I2(g) 2HI(g) Kc = 54.6 at 425C a. b. c. d. e.
4.78 103 M 9.55 103 M 2.34 103 M 1.17 103 M 1.85 104 M
ANS: B OBJ: Determine the reactant equilibrium concentrations given the product equilibrium concentration. TOP: Uses of the Equilibrium Constant, Kc
Whitten 10e
Test Bank
610
37. The equilibrium constant for the following gas phase reaction is 4.0 at a certain temperature. A reaction is carried out at this temperature starting with 2.0 mol/L of CO and 2.0 mol/L of H2O. What will be the equilibrium concentration of H2? CO + H2O CO2 + H2 a. b. c. d. e.
2.0 M 0.75 M 1.3 M 0.67 M 1.5 M
ANS: C OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 38. For the following reaction, Kc is 144 at 200C. If 0.400 mol of both A and B are placed in a 2.00-liter container at that temperature, what will be the concentration of C at equilibrium? A(g) + B(g) C(g) + D(g) a. b. c. d. e.
0.015 M 1.64 M 0.200 M 0.185 M 1.13 M
ANS: D OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 39. Ammonium carbamate decomposes into NH3 and CO2 when heated. NH4(NH2CO2)(s) 2NH3(g) + CO2(g) If 25.0 g of ammonium carbamate is placed in an empty chamber and heated to 100C, what are the equilibrium concentrations of NH3 and CO2? Kc = 58.3 at 100C. a. [NH3] = 2.44 M; [CO2] = 4.88 M b. [NH3] = 4.88 M; [CO2] = 2.44 M c. [NH3] = 29.2 M; [CO2] = 14.6 M d. [NH3] = 15.3 M; [CO2] = 7.64 M e. [NH3] = 10.8 M; [CO2] = 5.40 M ANS: B OBJ: Determine the product equilibrium concentrations given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 40. At 25C, Kc for the following reaction is 4.66 103. If 0.800 mol of N2O4 is injected into a closed 1.00-liter glass container at 25C, what will be the equilibrium concentration of N2O4? N2O4(g) 2NO2(g) a. b. c. d. e.
0.016 M 0.770 M 0.088 M 0.236 M 0.667 M
Whitten 10e
Test Bank
611
ANS: B OBJ: Determine the reactant equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 41. Exactly one mol/L of each of the four gases involved in the following reaction is placed in a reactor at 200C and allowed to reach equilibrium. What is the equilibrium concentration of H2O? Kc = 2.38 @ 200C. CO(g) + H2O(g) CO2(g) + H2(g) a. b. c. d. e.
1.21 M 0.213 M 0.787 M 2.38 M 1.0 M
ANS: C OBJ: Determine the reactant equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 42. The equilibrium constant, Kc, is 0.022 at 25C for the reaction below. What is the concentration of PCl5 at equilibrium if a reaction is initiated with 0.80 mole of PCl5 in a 1.00-liter container? PCl5(g) PCl3(g) + Cl2(g) a. b. c. d. e.
0.080 M 0.12 M 0.54 M 0.68 M 0.76 M
ANS: D OBJ: Determine the reactant equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 43. Phosgene, COCl2, is a poisonous gas that decomposes into carbon monoxide and chlorine according to the following equation with Kc = 0.083 at 900C. If the reaction is initiated with 0.600 mole of COCl2 at 900C in a 5.00-liter container, what concentration of CO will be present after equilibrium is established? COCl2(g) CO(g) + Cl2(g) a. b. c. d. e.
0.072 M 0.048 M 0.067 M 0.012 M 0.090 M
ANS: C OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc
Whitten 10e
Test Bank
612
44. Kc = 0.040 for the system below at 450C. If a reaction is initiated with 0.20 mole of Cl2 and 0.20 mole of PCl3 in a 1.0-liter container, what concentration of PCl5 will be present at equilibrium? PCl5(g) PCl3(g) + Cl2(g) a. b. c. d. e.
0.09 M 0.13 M 0.22 M 0.31 M 0.16 M
ANS: B OBJ: Determine the reactant equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 45. For the following system, the equilibrium constant at 445C is 51.0. If a reaction is initiated with the following initial concentrations, [H2] = 2.06 102 M, [I2] = 1.45 102 M, and [HI] = 0, what will be the equilibrium concentration of HI? H2(g) + I2(g) 2HI(g) a. b. c. d. e.
1.8 102 M 1.4 101 M 2.7 101 M 2.6 102 M 3.7 103 M
ANS: D OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 46. A reaction begins with 0.600 mole of A and 0.200 mole of B in a 2.00-L container at a certain temperature. What will be the equilibrium concentration of C? A(g) + B(g) C(g) Kc = 23.5 a. b. c. d. e.
0.0684 M 0.0200 M 0.044 M 0.0836 M 0.105 M
ANS: D DIF: Harder Question OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 47. For the following reaction, Kc is 144 at 200C. If the reaction were initiated with 0.600 mol of A and 0.200 mol of B in a 2.00-liter container, what would be the equilibrium concentration of A? A(g) + B(g) C(g) + D(g) a. b. c. d. e.
0.684 M 0.200 M 0.444 M 0.982 M 1.05 M
Whitten 10e
Test Bank
613
ANS: B OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Uses of the Equilibrium Constant, Kc 48. Which statement best represents LeChatelier's Principle? a. A system in equilibrium will always remain in equilibrium. b. Only a change in equilibrium will affect the equilibrium of a reaction. c. When a change is made to a system in equilibrium, equilibrium can never be restored. d. A system in equilibrium will respond to a change by moving in the direction that reduces the change as it returns to equilibrium. e. A system in equilibrium will not be affected by a change in concentration. ANS: D OBJ: Identify the definition of LeChatelier's principle. TOP: Disturbing a System in Equilibrium: Predictions 49. For the following system at equilibrium, H2(g) + CO2(g) H2O(g) + CO(g) the addition of H2(g) would cause (according to LeChatelier's principle) a. only more H2O(g) to form. b. only more CO(g) to form. c. more H2O(g) and CO(g) to form. d. only more CO2(g) to form. e. no change in amounts of products or reactants. ANS: C OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 50. For the following system at equilibrium, H2(g) + CO2(g) H2O(g) + CO(g) the removal of some of the H2O(g) would cause (according to LeChatelier's principle) a. more H2(g) to be form. b. more CO2(g) to be form. c. no change in the amounts of products or reactants. d. more CO(g) to be form. e. the amount of CO(g) to remain constant while the amount of H2O(g) increases to the original equilibrium concentration. ANS: D OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 51. If the system below is at equilibrium in a closed vessel and a small amount of nitrous acid is added, what would be expected to happen? HN3 + 2H2O N2H4 + HNO2 H0 = +641 kJ hydrazoic hydrazine nitrous acid acid a. b. c. d. e.
Some HN3 would be used up in re-establishing equilibrium. Some HNO2 would be formed in re-establishing equilibrium. Some HNO2 would be formed, and some N2H4 would be lost. More HN3 and H2O would be formed. The temperature would decrease, and the forward reaction would be favored.
Whitten 10e
Test Bank
614
ANS: D OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 52. Considering the following reaction at equilibrium, identify which of the stresses below would cause more products to form. CO(g) + Cl2(g) COCl2(g) H0 = 113 kJ/mol a. b. c. d. e.
Increase the pressure. Increase the [Cl2]. Increase the temperature. Both (a) and (b) are correct. All of these are correct.
ANS: D OBJ: Determine the change consistent with the stated outcome. TOP: Disturbing a System in Equilibrium: Predictions 53. For the following reaction, which of the changes listed below would cause more reactants to form when equilibrium is re-established? 2NOCl(g) + 75 kJ 2NO(g) + Cl2(g) a. b. c. d. e.
Add a catalyst. Increase the temperature. Decrease the [NO] Increase the volume. Increase the pressure.
ANS: E OBJ: Determine the change consistent with the stated outcome. TOP: Disturbing a System in Equilibrium: Predictions 54. Suppose we let the reaction below come to equilibrium. Then we decrease the total pressure, by increasing the volume of the container. What will be the effect on the net amount of SO3(g) present? 2SO2(g) + O2(g) 2SO3(g) a. b. c. d. e.
It increases. It decreases. It does not change. The question cannot be answered without knowing the value of K. The question cannot be answered without knowing the value of H0.
ANS: B OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions
Whitten 10e
Test Bank
615
55. Consider the reaction A(g) + B(g)
D(g) + Heat
Which of the following sets of reaction conditions would produce the maximum yield of product? a. 100C, 50 atm b. 100C, 10 atm c. 500C, 50 atm, catalyst d. 100C, 10 atm, catalyst e. 100C, 50 atm, catalyst ANS: E OBJ: Identify the conditions consistent with maximum yield. TOP: Disturbing a System in Equilibrium: Predictions 56. Suppose we let the reaction below come to equilibrium. Then we decrease the total pressure, by increasing the volume of the container. What will be the effect on the numerical value of the equilibrium constant, K? 2SO2(g) + O2(g) 2SO3(g) + heat a. b. c. d. e.
It increases. It decreases. It does not change. The question cannot be answered without knowing the initial value of K. The question cannot be answered without knowing the value of H0.
ANS: C OBJ: Determine the effect of a change on the equilibrium constant. TOP: Disturbing a System in Equilibrium: Predictions 57. Suppose the following reaction is at equilibrium at a given temperature and pressure. The pressure is then increased at constant temperature, by compressing the reaction mixture, and the mixture is allowed to re-establish equilibrium. At the new equilibrium ____. H2(g) + Cl2(g) 2HCl(g) a. b. c. d. e.
there is more hydrogen chloride than there was originally there is less hydrogen chloride than there was originally there is the same amount of hydrogen chloride as there was originally the hydrogen and chloride are completely used up the amount of hydrogen chloride may be either larger or smaller than it was originally, depending on the value of K
ANS: C OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 58. Decreasing the volume of the container (at constant temperature) after the system below has reached equilibrium would be expected to ____. HN3 + 2H2O N2H4 + HNO2 a. b. c. d. e.
produce more HN3 and raise the temperature produce more H2O and lower the temperature produce more N2H4 and raise the temperature produce more HNO2 and lower the temperature have no effect on this equilibrium
Whitten 10e
Test Bank
616
ANS: E OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 59. Suppose we let this reaction come to equilibrium. Then we increase the temperature of the reaction mixture. What will be the effect on the net amount of SO3(g) present? 2SO2(g) + O2(g) 2SO3(g) + heat a. b. c. d. e.
It increases. It decreases. It does not change. The question cannot be answered without knowing the value of K. The question cannot be answered without knowing the value of H0.
ANS: B OBJ: Determine the effect of a change on the product equilibrium concentration. TOP: Disturbing a System in Equilibrium: Predictions 60. Which of the numbered responses lists all the following stresses that would shift the equilibrium to the right (favor the forward reaction), and no other stresses? 2NOCl(g) + 75 kJ 2NO(g) + Cl2(g) I. II. III. IV. a. b. c. d. e.
Add more NOCl. Remove some Cl2. Lower the temperature. Add more NO. I and II I, II, and III I and III II and IV II, III, and IV
ANS: A OBJ: Identify the changes that shift the equilibrium to the right. TOP: Disturbing a System in Equilibrium: Predictions 61. Consider the following reaction: AB(s) + C2(g) AC(g) + BC(g) + heat Which of the following statements is false? a. Increasing PC2 will cause a shift to the left. b. Adding a catalyst will not affect the equilibrium. c. Decreasing the temperature will cause a shift to the right. d. Adding more AB(s) will not affect the equilibrium. e. Increasing PAC or PBC will cause a shift to the left. ANS: A OBJ: Identify the incorrect statement of cause and effect on an equilibrium. TOP: Disturbing a System in Equilibrium: Predictions
Whitten 10e
Test Bank
617
62. At equilibrium a 1.0-liter container was found to contain 0.20 mol of A, 0.20 mol of B, 0.40 mol of C, and 0.40 mol of D. If 0.10 mol of A and 0.10 mol of B are added to this system, which of the following statements is true? A(g) + B(g) C(g) + D(g) a. b. c. d. e.
The system remains in equilibrium. Q > Kc More reactants are formed to increase the value of Q. The value of Kc decreases. More products are formed to increase the value of Q.
ANS: E OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 63. For the gas phase reaction below, H0 = 1.6 102 kJ for the forward reaction. SO2 + O2
SO3
In order to increase the yield of SO3, the reaction should be run a. at high P, high T. b. at high P, low T. c. at low P, high T. d. at low P, low T. e. at high P, but is independent of T. ANS: B OBJ: Identify the conditions required to increase yield. TOP: Disturbing a System in Equilibrium: Predictions 64. Which of the following will require the least time for a reaction to reach equilibrium? a. Kc is a very small number. b. Kc is a very large number. c. Kc is approximately one. d. Cannot tell without knowing the value of Kc. e. Cannot tell, since the time required to reach equilibrium does not depend on Kc. ANS: E OBJ: Understand the difference between kinetics and equilibrium. TOP: Disturbing a System in Equilibrium: Predictions 65. Which of the following statements about the Haber process is false? a. Fritz Haber, a German scientist, developed the process. b. Higher temperature favors the forward reaction. c. Most NH3 produced by the Haber process is used to make fertilizer. d. Ammonia is synthesized from elemental nitrogen and hydrogen. e. Higher gas pressures favor the forward reaction. ANS: B OBJ: Identify the incorrect description of the Haber process. TOP: The Haber Process
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66. Suppose the following reaction is at equilibrium at a given temperature and pressure. The pressure is then increased at constant temperature, by compressing the reaction mixture, and the mixture is allowed to re-establish equilibrium. At the new equilibrium ____. N2(g) + 3H2(g) 2NH3(g) a. b. c. d. e.
there is more ammonia than there was originally there is less ammonia than there was originally there is the same amount of ammonia present as there was originally the nitrogen is used up completely the amount of ammonia may be either larger or smaller than it was originally, depending on the value of K
ANS: A OBJ: Determine the effect of change to a system at equilibrium. TOP: The Haber Process 67. Consider the following reversible reaction at equilibrium. N2(g) + 3H2(g) 2NH3(g) + 9.22 104 J Which response contains all the choices below that refer to changes that would shift the equilibrium to the right, and no other choices? I. add H2 II. remove N2 III. add an iron catalyst IV. increase the temperature at constant pressure V. increase the pressure at constant temperature by decreasing the volume a. b. c. d. e.
III, IV and V I, IV and V IV and V I, II and III I and V
ANS: E OBJ: Identify the changes that shift the equilibrium to the right. TOP: The Haber Process 68. The Haber process demonstrates that commercial processes do not maximize each factor that affects equilibria but use them in combination to get maximum production. Which of the following statements about the Haber process is false? N2(g) + 3H2(g) 2NH3(g) + 92.24 kJ a. b. c. d.
Although Kc is much greater at 25C, the reaction is carried out at 450C. A catalyst is used to increase reaction rate. Although the reaction is exothermic, it is carried out at high (450C) temperature. Although high pressure is unfavorable to the production of the NH3(g), the reaction is carried out under a pressure of 2001000 atmospheres. e. The emerging reaction mixture is cooled to remove the NH3 and the N2 and H2 recycled. ANS: D OBJ: Identify the incorrect description of the Haber process. TOP: The Haber Process
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Test Bank
619
69. A system at equilibrium in a 1.0-liter container was found to contain 0.20 mol of A, 0.20 mol of B, 0.40 mol of C, and 0.40 mol of D. If 0.15 mol of A and 0.15 mol of B are added to this system, what will be the new equilibrium concentration of A? A(g) + B(g) C(g) + D(g) a. b. c. d. e.
0.050 M 0.10 M 0.20 M 0.25 M 0.30 M
ANS: D OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Calculations 70. The following system is at equilibrium with [N2O4] = 0.55 M and [NO2] = 0.25 M. If an additional 0.10 M NO2 is added to the reaction mixture with no change in volume, what will be the new equilibrium concentration of N2O4? N2O4(g) 2NO2(g) a. b. c. d. e.
0.59 M 0.65 M 0.26 M 0.45 M 0.70 M
ANS: A OBJ: Determine the reactant equilibrium concentration given the initial reaction conditions. TOP: Disturbing a System in Equilibrium: Calculations 71. A system at equilibrium in a 1.0-liter container was found to contain 0.20 mol of A, 0.20 mol of B, 0.40 mol of C, and 0.40 mol of D. If 0.12 mol of A and 0.12 mol of B are added to this system, what will be the new equilibrium concentration of C? A(g) + B(g) C(g) + D(g) a. b. c. d. e.
0.32 M 0.13 M 0.24 M 0.40 M 0.48 M
ANS: E OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Disturbing a System in Equilibrium: Calculations 72. A 1.00-liter vessel contains the following equilibrium concentrations at 400C: N2, 1.00 M; H2, 0.50 M; and NH3, 0.50 M. How many moles of hydrogen must be removed from the vessel in order to increase the concentration of nitrogen to 1.20 M? N2(g) + 3H2(g) 2NH3(g) a. b. c. d. e.
0.94 mol 1.5 mol 0.33 mol 0.76 mol 1.1 mol
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620
ANS: A DIF: Harder Question OBJ: Determine the change in moles of reactant consistent with the stated outcome and initial conditions. TOP: Disturbing a System in Equilibrium: Calculations 73. Given: A(g)
B(g) + C(g)
When the system is at equilibrium at 200C, the concentrations are found to be: [A] = 0.20 M, [B] = 0.30 M, [C] = 0.30 M. If the volume of the container is suddenly doubled at 200C, what will be the new equilibrium concentration of C? a. 0.060 M b. 0.18 M c. 0.24 M d. 0.29 M e. 0.35 M ANS: B OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Calculations 74. Given: A(g)
B(g) + C(g)
When the above system is at equilibrium at 200C, the concentrations are found to be: [A] = 0.20 M, [B] = [C] = 0.30 M. If the volume of the container is suddenly doubled at 200C, what will be the new equilibrium concentration of A? a. 0.03 M b. 0.05 M c. 0.07 M d. 0.09 M e. 0.11 M ANS: C OBJ: Determine the effect of change to a system at equilibrium. TOP: Disturbing a System in Equilibrium: Calculations 75. Given: PCl5(g)
PCl3(g) + Cl2(g)
Kc = 0.040 at 450C
What would be the equilibrium concentration of PCl5(g) if 0.20 mole of PCl5(g) was placed in a 1.00-L container at this temperature? What would be the new equilibrium concentration of PCl5(g) if the volume were halved at this same temperature? a. 0.070 M; 0.29 M b. 0.13 M; 0.29 M c. 0.13 M; 0.11 M d. 0.070 M; 0.13 M e. 0.060 M; 0.14 M ANS: B OBJ: Determine the reactant equilibrium concentration given the initial reaction conditions. TOP: Disturbing a System in Equilibrium: Calculations
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Test Bank
621
76. Given: N2(g) + O2(g)
2NO(g)
Kc = 0.16
What would be the equilibrium concentration of N2(g) if 0.12 mole of NO(g) was placed in a 1.00-L container at this temperature? What would be the new equilibrium concentration of N2(g) if the volume were halved at this same temperature? a. 0.050 M; 0.10 M b. 0.050 M; 0.12 M c. 0.070 M; 0.12 M d. 0.10 M; 0.10 M e. 0.50 M; 1.0 M ANS: A DIF: Harder Question OBJ: Determine the product equilibrium concentration given the initial reaction conditions. TOP: Disturbing a System in Equilibrium: Calculations 77. When equilibrium is established for the following reaction at 298 K, the concentration of N2O4 is 1.34 mol/L, and the concentration of NO2 is 0.448 mol/L. Convert these concentrations to partial pressures. What is the total pressure of the system at equilibrium? N2O4(g) 2NO2(g) a. b. c. d. e.
2.54 atm 11.6 atm 16.7 atm 34.4 atm 43.8 atm
ANS: E OBJ: Determine the total pressure of the system at equilibrium given the initial conditions. TOP: Partial Pressures and the Equilibrium Constant 78. A mixture of 0.40 mol of N2, 0.60 mol of Ar, and 0.30 mol of O2 is confined in a 300-liter vessel at 50.0C. What is the total pressure of the system? a. 0.32 atm b. 0.016 atm c. 0.049 atm d. 0.086 atm e. 0.11 atm ANS: E OBJ: Determine the total pressure of the system at equilibrium given the initial conditions. TOP: Partial Pressures and the Equilibrium Constant
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Test Bank
622
79. The equilibrium constant expression for the reaction, 2CO(g) + O2(g) 2CO2(g) is given by Kp = a.
b.
c. d.
e.
ANS: A OBJ: Determine the equilibrium expression given the balanced reaction. TOP: Partial Pressures and the Equilibrium Constant 80. The equilibrium constant expression for the reaction, 2NO2(g) O2(g) + 2NO(g) is given by Kp = a.
b.
c. d.
e.
ANS: D OBJ: Determine the equilibrium expression given the balanced reaction. TOP: Partial Pressures and the Equilibrium Constant
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Test Bank
623
81. Consider the reversible reaction at equilibrium at 392C. 2A(g) + B(g) C(g) The partial pressures are found to be: A: 6.70 atm, B: 10.1 atm, C: 3.60 atm. Evaluate Kp for this reaction. a. 7.94 103 b. 1.46 101 c. 5.32 102 d. 54.5 e. 121 ANS: A OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: Partial Pressures and the Equilibrium Constant 82. For the following reaction at equilibrium at 445C the partial pressures were found to be: [H2] = 0.45 atm, [I2] = 0.10 atm and [HI] = 1.53 atm. Calculate Kp for this reaction. H2(g) + I2(g) 2HI(g) a. b. c. d. e.
150 34 52 76 4.4
ANS: C OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: Partial Pressures and the Equilibrium Constant 83. For the following gas-phase reaction at 400 K, KP = 17.1. 2A B+C If initially the total pressure in the reactor is 1.80 atm and only A is present, what is the total pressure in the reactor at equilibrium? a. 2.20 atm b. 3.54 atm c. 0.803 atm d. 17.1 atm e. 1.80 atm ANS: E OBJ: Determine the total pressure of the system at equilibrium given the initial conditions. TOP: Partial Pressures and the Equilibrium Constant 84. At 500C, the following reaction has Kp = 133. If a reaction is initiated with the partial pressure of each gas at 1.0 atm, what is the total pressure of the reaction mixture at equilibrium? H2(g) + Br2(g) 2 HBr(g) a. b. c. d. e.
1.0 atm 3.0 atm 0.77 atm 2.0 atm 4.0 atm
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Test Bank
624
ANS: B OBJ: Determine the total pressure of the system at equilibrium given the initial conditions. TOP: Partial Pressures and the Equilibrium Constant 85. Phosphorus pentafluoride, PF5(g), partially decomposes to PF3(g) and F2(g) at a temperature of 600 K. A 2.0-liter container is filled with pure PF5. At a temperature of 600 K, the initial pressure of PF5 is 2.0 atm. When equilibrium is reached, half of the original amount of PF5 has decomposed. The equilibrium constant, Kp, is ____. PF5(g) PF3(g) + F2(g) a. b. c. d. e.
0.0025 0.12 0.25 0.50 1.0
ANS: E OBJ: Calculate K from initial and equilibrium concentrations. TOP: Partial Pressures and the Equilibrium Constant 86. The partial pressure of a certain gas in a system at equilibrium at 10.C is experimentally determined to be 0.340 atmosphere. What is its concentration in moles per liter? a. 4.14 101 M b. 1.46 102 M c. 68.2 M d. 2.79 101 M e. 7.90 M ANS: B OBJ: Convert pressure to molarity. TOP: Relationship Between Kp and Kc 87. Consider the reversible reaction at equilibrium at 392C. 2A(g) + B(g) C(g) The partial pressures are found to be: A: 6.70 atm, B: 10.1 atm, C: 3.60 atm. What is the concentration of B at equilibrium? a. 0.015 M b. 1.64 M c. 0.200 M d. 0.185 M e. 1.13 M ANS: D OBJ: Determine the missing equilibrium concentration. TOP: Relationship Between Kp and Kc
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Test Bank
625
88. Kc = 4.6 103 for the reaction below at 25C. Evaluate Kp at 25C. N2O4(g) 2NO2(g) a. b. c. d. e.
0.086 0.11 6.2 103 1.9 104 3.2 101
ANS: B OBJ: Convert Kc to Kp. TOP: Relationship Between Kp and Kc 89. Kc = 2.3 102 for the reaction below at 100C. Evaluate Kp at 100C. CO2(g) + H2(g) CO(g) + H2O(g) a. b. c. d. e.
43.5 2.3 102 1.73 7.0 104 7.5 101
ANS: B OBJ: Convert Kc to Kp. TOP: Relationship Between Kp and Kc 90. Kc = 0.040 for the system below at 450.C. Evaluate Kp for the reaction at 450.C. PCl5(g) PCl3(g) + Cl2(g) a. b. c. d. e.
0.40 0.64 2.4 5.2 102 6.7 104
ANS: C OBJ: Convert Kc to Kp. TOP: Relationship Between Kp and Kc 91. For the reaction below, Kp = 203 at 105C. Calculate Kc at 105C. A(g) + 3B(g) AB3(g) a. b. c. d. e.
6.5 1012 6.3 103 1.7 103 1.3 105 6.1 106
ANS: E OBJ: Convert Kp to Kc. TOP: Relationship Between Kp and Kc
Whitten 10e
Test Bank
626
92. Given: PCl5(g)
PCl3(g) + Cl2(g)
At 250.C a sample of PCl5 was placed in a 24-liter evacuated reaction vessel and allowed to come to equilibrium. Analysis showed that at equilibrium 0.42 mole of PCl5, 0.64 mole of PCl3, and 0.64 mole of Cl2 were present in the vessel. Calculate Kp for the reaction at 250.C. a. 1.2 b. 1.3 c. 1.5 d. 1.8 e. 2.2 ANS: D OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: Relationship Between Kp and Kc 93. Certain amounts of the hypothetical substances A2 and B are mixed at 300. K. When equilibrium is established for the reaction below, the following amounts were present in a 3.00-liter container: 0.200 mole of A2, 0.400 mole of B, 0.200 mole of D, and 0.100 mole of E. What is Kp, the equilibrium constant, in terms of partial pressures (atm), for this reaction? A2(g) + 3B(g) 2D(g) + 3E(g) a. b. c. d. e.
16.4 0.084 3.81 102 2.57 102 1.46 102
ANS: D OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: Relationship Between Kp and Kc 94. Certain amounts of the hypothetical substances A2 and B are mixed in a 3.00-liter container at 300. K. When equilibrium is established for the reaction the following amounts are present: 0.200 mol of A2, 0.400 mol of B, 0.200 mol of D, and 0.100 mol of E. What is Kp, the equilibrium constant, in terms of partial pressures, for this reaction? A2(g) + 3B(g) 2D(g) + E(g) a. b. c. d. e.
16.4 0.084 3.81 102 1.42 102 2.50 101
ANS: C OBJ: Calculate K given the reactant and product equilibrium concentrations. TOP: Relationship Between Kp and Kc 95. For the reaction below, Kp = 6.70 103 at 25C. COCl2(g) CO(g) + Cl2(g) A sample of COCl2 is placed in a closed 15.0-liter vessel at 25C, and it exerts a pressure of 4.65 atm before decomposition begins. What will be the partial pressure of Cl2 at equilibrium?
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627
a. b. c. d. e.
0.173 atm 0.206 atm 0.566 atm 2.14 atm 1.16 atm
ANS: A OBJ: Determine the product equilibrium pressure given the initial reaction conditions. TOP: Relationship Between Kp and Kc 96. The equilibrium constant, Kp, for the following reaction is 280. at 150.C. Suppose that a quantity of IBr is placed in a closed reaction vessel and the system is allowed to come to equilibrium at 150.C. When equilibrium is established, the pressure of IBr is 0.200 atm. What is the pressure of I2 at equilibrium? I2(g) + Br2(g) 2IBr(g) + 11.7 kJ a. b. c. d. e.
0.168 atm 0.096 atm 0.067 atm 0.012 atm 0.00014 atm
ANS: D OBJ: Determine the reactant equilibrium pressure given the initial reaction conditions and the equilibrium product pressure. TOP: Relationship Between Kp and Kc 97. For the reaction below, Kp = 1.59 at 100C. If 1.0 g of SrCO3 is placed in an empty 5.00 L reactor and allowed to reach equilibrium, what will be the pressure in the reactor? SrCO3(s) SrO(s) + CO2(g) a. b. c. d. e.
1.59 atm 1.26 atm 2.53 atm 1.0 atm 3.18 atm
ANS: A OBJ: Determine the total pressure of the system at equilibrium given the initial conditions. TOP: Relationship Between Kp and Kc 98. The equilibrium constant, Kp, for the following reaction is 355 at 175C. If one mole of each A, B and C is placed in a 2.00 L reactor at 175C, what is the partial pressure of A at equilibrium? 2A B+C a. b. c. d. e.
8.48 atm 1.44 atm 26.9 atm 9.92 atm 2.00 atm
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Test Bank
628
ANS: B OBJ: Determine the reactant equilibrium pressure given the initial reaction conditions. TOP: Relationship Between Kp and Kc 99. For the reaction below, Kp = 6.70 103 at 25C. COCl2(g) CO(g) + Cl2(g) A sample of COCl2 is placed in a closed 15.0-liter vessel at 25C, and it exerts a pressure of 4.65 atm before decomposition begins. What will be the total pressure at equilibrium? a. 1.68 atm b. 3.80 atm c. 5.03 atm d. 4.65 atm e. 4.83 atm ANS: E OBJ: Determine the total pressure of the system at equilibrium given the initial conditions. TOP: Relationship Between Kp and Kc 100. The equilibrium constant, Kp, for the following reaction is 280. at 150.C. Suppose that a quantity of IBr is placed in a closed reaction vessel and the system is allowed to come to equilibrium at 150.C. When equilibrium is established, the pressure of IBr is 0.200 atm. What is the total pressure inside the system at equilibrium? I2(g) + Br2(g) 2IBr(g) + 11.7 kJ a. b. c. d. e.
0.176 atm 0.212 atm 0.224 atm 0.334 atm 0.536 atm
ANS: C OBJ: Determine the total pressure at equilibrium given the initial reaction conditions and the equilibrium product pressure. TOP: Relationship Between Kp and Kc 101. The gas phase system below is at equilibrium at 200C with the following partial pressures: 0.20 atm A, 0.20 atm B, 0.10 atm C, and 0.40 atm D. If an additional 0.30 atm C is introduced into the reaction vessel, what will be the partial pressure of C at 200C when equilibrium is re-established? A(g) + B(g) C(g) + D(g) a. b. c. d. e.
0.60 atm 0.30 atm 0.50 atm 0.75 atm 0.45 atm
ANS: B OBJ: Determine the reactant equilibrium pressure after a change to the given the equilibrium conditions. TOP: Relationship Between Kp and Kc
Whitten 10e
Test Bank
629
102. Given the equilibrium reaction: ZnCO3(s) ZnO(s) + CO2(g) Which one of the following statements is true? a. Equal concentrations of ZnO(s) and CO2(g) would result from the decomposition of a given amount of ZnCO3(s). b. The same equilibrium condition would result if we started with only pure ZnCO3(s) in a closed container as if we started with only pure ZnO(s) in a closed container. c. Introducing 1.0 atm pressure of N2(g) into the system at equilibrium in a closed container would result in more ZnCO3(s) being formed. d. Decreasing the volume of the closed system initially at equilibrium, at constant temperature, would result in more ZnCO3(s) being formed. e. At equilibrium conditions, the forward and reverse reactions have stopped. ANS: D OBJ: Identify the correct statement of cause and effect on an equilibrium. TOP: Heterogeneous Equilibria 103. Which one of the following would force the forward reaction to completion? CaCO3(s) + 2H3O+(aq) Ca2+(aq) + 3H2O + CO2(g) a. b. c. d. e.
Removing some H3O+ from the reaction mixture, by neutralizing it with base. Adding more Ca2+ to the mixture. Removing CO2 as it is formed. Adding CO2 to the reaction mixture. None of these would have any effect on the amount of CaCO3 consumed.
ANS: C OBJ: Identify the changes that shift the equilibrium to the right. TOP: Heterogeneous Equilibria 104. Consider the following heterogeneous reaction: Mg(s) + 2H3O+(aq) Mg2+(aq) + H2(g) + 2H2O Which of the following statements is false? a. The amount of magnesium present does not affect the equilibrium position. b. Adding 1.0 atm of N2 to the system would cause the reverse reaction to be favored. c. Increasing causes the forward reaction to be favored. d. Increasing [H3O+] causes the forward reaction to be favored. e. Decreasing [Mg2+] causes the forward reaction to be favored. ANS: C OBJ: Identify the incorrect statement of cause and effect on an equilibrium. TOP: Heterogeneous Equilibria 105. Consider the equilibrium decomposition of ammonium bromide. NH4Br(s) NH3(g) + HBr(g) Once equilibrium is established, which of the following would cause this reaction to favor the products more?
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630
a. b. c. d. e.
Increase the total pressure. Increase the amount of NH4Br. Decrease the amount of NH4Br. Increase PHBr. Decrease .
ANS: E OBJ: Identify the changes that shift the equilibrium to the right. TOP: Heterogeneous Equilibria 106. A sample of only solid ammonium chloride was heated in a closed container NH4Cl(s) NH3(g) + HCl(g) At equilibrium, the pressure of NH3(g) was found to be 2.50 atm. What is the equilibrium constant, Kp, for the decomposition at this temperature? a. 1.46 b. 1.58 c. 6.25 d. 5.00 e. 15.6 ANS: C OBJ: Calculate K given the initial conditions and a product equilibrium concentration. TOP: Heterogeneous Equilibria 107. A sample of only solid ammonium chloride was heated in a 1.00-L container at 500.C: NH4Cl(s) NH3(g) + HCl(g) At equilibrium, the pressure of NH3(g) was found to be 1.75 atm. What is the equilibrium constant, Kc, for the decomposition at this temperature? a. 7.6 104 b. 1.2 104 c. 4.8 102 d. 1.9 102 e. 1.8 103 ANS: A DIF: Harder Question OBJ: Calculate K given the initial conditions and a product equilibrium concentration. TOP: Heterogeneous Equilibria 108. At 1470 K the value of Kp = 6.0 104 for the reaction below: 2CO(g) C (graphite) + CO2(g) CO(g) initially at 2.00 atm is in contact with graphite until equilibrium is reached. What is the partial pressure of CO2(g) at equilibrium? a. 0.0024 atm b. 0.00030 atm c. 0.0012 atm d. 0.00060 atm e. 0.00015 atm
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Test Bank
631
ANS: A DIF: Harder Question OBJ: Determine the reactant equilibrium pressure given the initial reaction conditions. TOP: Heterogeneous Equilibria 109. Which of the following statements about G0 and the thermodynamic equilibrium constant is false? a. G0 and K are both indicators of the direction of a spontaneous reaction. b. When G0 < 0, the forward reaction is favored. c. When K < 1, the reverse reaction is favored. d. There is a mathematical relationship between G0 and K. e. When G0 < 0, K < 1. ANS: E OBJ: Identify the incorrect description of delta G and K. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 110. Which of the following pairs are incorrectly matched? a. Negative G0 / K > 1 b. Product-favored / K > 1 c. Reactant-favored / positive G0 d. K = 0.053 / G0 must be positive e. G0 = 16 kJ / K must be < 1 ANS: E OBJ: Identify the incorrect description of delta G and K. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 111. Calculate the thermodynamic equilibrium constant at 25C for a reaction for which G0 = 18.3 kJ per mol of reaction. R = 8.314 J/molK a. 0.993 b. 1.01 c. 4.56 d. 6.20 104 e. 4.32 1024 ANS: D OBJ: Calculate K given delta G. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 112. Calculate the thermodynamic equilibrium constant at 25C for a reaction for which G0 = 25.60 kJ per mol of reaction. R = 8.314 J/molK a. 5.14 101 b. 11.2 c. 6.12 102 d. 3.07 104 e. 4.32 106 ANS: D OBJ: Calculate K given delta G. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant
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Test Bank
632
113. Evaluate the thermodynamic equilibrium constant for the following reaction at 25C. CH4(g) + H2O(g) CO(g) + 3H2(g) 0 60.63 228.6 137.2 kJ/mol a. b. c. d. e.
5.5 1074 2.2 1027 3.4 1054 4.4 1026 1.8 1075
ANS: B OBJ: Calculate K given the balanced reaction and delta G's of formation. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 114. Calculate the equilibrium constant at 25C for the following reaction. R = 8.314 J/molK. I2(s) + Cl2(g) 2ICl(g) 0 0 5.52 kJ/mol a. b. c. d. e.
86 57 2.9 104 4.1 4.5
ANS: A OBJ: Calculate K given the balanced reaction and delta G's of formation. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 115. Consider the following reaction at 25C for which H0 is 26.9 kJ and S0 is 11.4 J/K. Evaluate the equilibrium constant, Kp, for the reaction at 25C. R = 8.314 J/molK I2(g) + Cl2(g) 2ICl(g) a. b. c. d. e.
3.6 106 4.2 103 2.0 105 6.7 108 4.9 106
ANS: C OBJ: Calculate K given delta H and delta S. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 116. Evaluate G0 at 718C for a gas phase reaction for which Kp = 7.4 106 at 718C. R = 8.314 J/molK a. 68.6 kJ b. 365 kJ c. 427 kJ d. 97.3 kJ e. 168 kJ ANS: D OBJ: Calculate delta G given K. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant
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633
117. Kp for a gas phase reaction is 4.7 102 at 660.C. Evaluate G0 at 660.C. R = 8.314 J/molK a. 23.7 kJ b. 109 kJ c. 2.46 kJ d. 31.5 kJ e. 16.1 kJ ANS: A OBJ: Calculate delta G given K. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 118. Evaluate G0 for a gas phase reaction for which Kp = 3.1 105 at 718C. a. 62.4 kJ b. 85.6 kJ c. 98.2 kJ d. 110 kJ e. 138 kJ ANS: B OBJ: Calculate delta G given K. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 119. The van't Hoff equation relates two equilibrium constants at two different temperatures.
Consider a reaction where K298 = 16.3 and H0 = 116 kJ/mol. Which of the following statements is true? a. The reverse reaction is favored at 298 K. b. A decrease in temperature will cause the forward reaction to be favored more. c. An increase in temperature will cause the forward reaction to be favored more. d. The value of K would be larger at 398 K. e. The reaction is endothermic. ANS: B OBJ: Identify the correct application and interpretation of the van't Hoff equation. TOP: Evaluation of Equilibrium Constants at Different Temperatures 120. The value of Kp at 390.C for the reversible reaction given below is 7.95 103. Calculate the value of Kp at 25C. H0 = 162 kJ/mol, R = 8.314 J/molK A(g) + B(g) C(g) a. b. c. d. e.
2.8 102 1.8 1018 6.3 1012 3.0 1014 3.4 1013
ANS: B OBJ: Calculate K using the van't Hoff equation. TOP: Evaluation of Equilibrium Constants at Different Temperatures
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634
121. If the Kp at 2000. K for the reaction given below is 2.1 103 and the Kp at 27C is 5.0 1030, calculate H0 for this reaction. A(g) + B(g) C(g) a. b. c. d. e.
2.6 kJ 1.44 J 179 kJ 180 kJ 13.9 kJ
ANS: D OBJ: Calculate delta H using the van't Hoff equation. TOP: Evaluation of Equilibrium Constants at Different Temperatures 122. If the Kp at 2000. K for the reaction given below is 2.1 103, at what temperature would the value of Kp = 5.0 1010? H0 for this reaction is 180 kJ/mol. A(g) + B(g) C(g)
a. b. c. d. e.
433 K 718C 557C 800 K 2000 K
ANS: C OBJ: Calculate temperature using the van't Hoff equation. TOP: Evaluation of Equilibrium Constants at Different Temperatures 123. A 25.00-L vessel at 700 K initially contains HI(g) at a pressure of 6.00 atm; at equilibrium, it is found that the partial pressure of H2(g) is 0.581 atm. What is the partial pressure of HI(g) at equilibrium? 2HI(g) a. b. c. d. e.
H2(g) + I2(g)
6.00 atm 5.42 atm 4.84 atm 6.58 atm 0.581 atm
ANS: C DIF: easy OBJ: Determine the reactant equilibrium pressure after a change to the given the equilibrium conditions. TOP: Equilibrium
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124. What is the balanced equation for the following equilibrium expression?
a. b. c. d. e.
6SO2(g) + 3O2(g) 6SO3(g) 6SO3(g) 6SO2(g) + 3O2(g) 6SO3(aq) 6SO2(aq) + 3O2(aq) 6SO2(aq) + 3O2(aq) 6SO3(aq) SO2(g) + O2(g)
SO3(g)
ANS: A DIF: easy OBJ: Identify the balanced equilibrium consistent with the given equilibrium expression. TOP: Variation of Kc with the Form of the Balanced Equation 125. For the reaction Br2(g) + Cl2(g) 2BrCl(g), at equilibrium, it is found that the concentrations of Br2, Cl2, and BrCl are 0.277 M, 0.388 M, and 1.80 103 M, respectively. What is the value of Kc? a. 3.01 105 b. 1.67 102 c. 5.97 101 d. 3.32 104 e. 3.24 106 ANS: A DIF: easy OBJ: Calculate Kc given the balanced equation and equilibrium concentrations. TOP: Uses of the Equilibrium Constant, Kc 126. A sample of ammonia gas was allowed to come to equilibrium at 400 K. 2NH3(g)
N2(g) + 3H2(g)
At equilibrium, it was found that the concentration of H2 was 0.0367 M, the concentration of N2 was 0.0122 M, and the concentration of NH3 was 0.170 M. What was the initial concentration of ammonia? a. 0.122 M b. 0.146 M c. 0.218 M d. 0.182 M e. 0.194 M ANS: E DIF: moderate OBJ: Determine the initial concentration of reactant given the equilibrium concentrations. TOP: Disturbing a System in Equilibrium: Calculations
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127. For the reaction 2NO(g) + O2(g) Kp? a. Kc = Kp b. Kc = Kp (RT)–1 c. Kc = Kp = 1.0 d. Kc = Kp (RT)¾ e. Kc = Kp (RT)1
2NO2(g) at 750°C, what is the relationship between Kc and
ANS: E DIF: moderate OBJ: Determine the relationship between Kc and Kp given the balanced equilibrium. TOP: Relationship Between Kp and Kc 128. Given the equilibrium constants for the equilibria, NH4+(aq) + H2O(l)
NH3(aq) + H3O+(aq); Kc = 5.69 1010
2CH3COOH(aq) + 2H2O(l)
2CH3COO(aq) + 2H3O+(aq); Kc = 3.06 1010
determine Kc for the following equilibrium. CH3COOH(aq) + NH3(aq) a. b. c. d. e.
CH3COO(aq) + NH4+(aq)
3.08 x104 3.25 x10-5 9.96 x10-15 1.00 x1014 1.75 x10-5
ANS: A DIF: moderate OBJ: Determine the equilibrium constant by summing two given equilibria. TOP: Equilibrium 129. What is the Kc expression for the following equilibrium? TlSCN(s) + H2O(l)
Tl+(aq) + SCN(aq)
a. b.
c.
d.
e.
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ANS: A DIF: easy OBJ: Identify the expression for Kc for the given heterogeneous equilibrium. TOP: Heterogeneous Equilibria 130. Which of the following is always true for a reaction where Kc is 4.26 106 at 25C? a. The reaction mixture contains mostly products at equilibrium. b. The reaction mixture contains mostly reactants at equilibrium. c. The rate of reaction is very fast. d. There are approximately equal moles of reactants and products at equilibrium. e. Both A and C. ANS: A DIF: easy OBJ: Give a qualitative interpretation of the equilibrium constant based on its value. TOP: The Equilibrium Constant 131. What is the reaction quotient (Q) for the equilibrium TlCl(s) + H2O(l)
Tl+(aq) + Cl(aq)
when 0.6641 L of 1.342 102 M Tl+ is combined with 0.5864 L of 4.472 103 M Cl in the presence of an excess of TlCl(s)? a. 1.494 105 b. 6.000 105 c. 2.337 105 d. 1.869 105 e. 9.383 105 ANS: A DIF: moderate OBJ: Determine the reaction quotient given the volume and concentration of reactants and products. TOP: The Reaction Quotient 132. When the pressure of an equilibrium mixture of SO2, O2, and SO3 is doubled at constant temperature, what the effect on Kp? 2SO2(g) + O2(g) a. b. c. d. e.
2SO3(g)
Kp is halved. Kp is doubled. Kp is unchanged. Kp is tripled. Kp is decreased by a third.
ANS: A DIF: moderate OBJ: Predict the change in Kp for a given change in pressure. TOP: Disturbing a System in Equilibrium: Predictions
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133. For the reaction, N2O4(g)
2NO2(g), which of the following statements is true about this reaction at equilibrium? a. The concentration of NO2 is equal to the concentration of N2O4 b. The rate of the dissociation of N2O4 is equal to the rate of formation of N2O4 c. The rate constant for the forward reaction is equal to the rate constant for the reverse reaction d. The concentration of NO2 divided by the concentration of N2O4 is equal to a constant e. Two of the above ANS: B OBJ: State in words the meaning of chemical equilibrium. TOP: Equilibrium
134. The reaction: 2S(s) + 3O2(g)
2SO3(g) has an equilibrium constant of K = 1.91. What is the value of the equilibrium constant for the reaction: SO3(g) S(s) + 3/2 O2(g) ? a. 0.274 b. 0.524 c. 0.724 d. 1.38 e. 3.65 ANS: C OBJ: Calculate a new equilibrium constant given the change in the stoichiometric coefficients of the balanced equation. TOP: Variation of Kc with the Form of the Balanced Equation
135. Consider the following reaction:
2 CH2Cl2(g) CH4(g) + CCl4(g) An equilibrium mixture of the three gases in a 14.1 L container at 352K contains 0.121 moles of CH2Cl2, 0.661 moles of CH4, and 0.223 moles of CCl4. What is the value of the equilibrium constant at 352K? a. 0.0254 b. 0.0864 c. 0.0993 d. 10.1 e. 11.6 ANS: D OBJ: Calculate K given the equilibrium concentrations. TOP: Uses of the Equilibrium Constant, Kc
136. A student ran the following reaction in the laboratory at 1090 K:
2SO3(g) 2SO2(g) + O2(g) When she introduced 0.0683 moles of SO3 gas into a 1.00L container, she found the equilibrium concentration of O2 gas to be 0.0152 M. What is the value of the equilibrium constant, K? a. 0.00498 b. 0.00978 c. 0.0122 d. 0.0125 e. 0.0152 ANS: B OBJ: Calculate K nonequilibrium and equilibrium concentrations. TOP: Equilibrium 137. Consider the following reaction where Kc = 1.18 at 150K:
2HI(g) H2(g) + I2(s) A reaction mixture was found to contain 0.0381 moles of HI, 0.0471 moles of H2, and 0.0364 moles of I2 in a 1.00 L container. Is the reaction at equilibrium? And if not, what direction must it run in order to reach equilibrium?
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a. The reaction is at equilibrium b. The reaction must run towards the products to reach equilibrium c. The reaction must run towards the reactants to reach equilibrium ANS: C OBJ: Use the reaction quotient to determine if a reaction is at equilibrium and what direction it must proceed to attain equilibrium. TOP: The Reaction Quotient -4
138. The equilibrium constant, Kp, for the following reaction is 4.44 x 10 at 452K.
(CH3)2CHOH(g) (CH3)2CO(g) + H2(g) Calculate the equilibrium partial pressure of (CH3)2CHOH when (CH3)2CHOH is introduced into an evacuated flask at a pressure of 1.04 atm at 452K. a. 0.000462M b. 0.0207M c. 0.0215M d. 1.02M e. 1.039M ANS: D OBJ: Calculate the equilibrium partial pressure given K and the nonequilibrium pressure. TOP: Equilibrium 139. Consider the following system at equilibrium:
2SO3(g) 2SO2(g) + O2(g) Kc = 2.90 x 10-2 and Ho = 198 kJ/mol at 1150K. Which of the following changes will favor the production of SO2? a. Increasing the temperature b. Increasing the pressure c. Adding O2 gas d. Adding sulfur, S e. Adding a catalyst ANS: A OBJ: Identify the change which will increase the equilibrium concentration of product. TOP: Disturbing a System in Equilibrium: Predictions 140. An indicator, HIn, shows a color change from blue to yellow, depending on the acidity of the
solution: HIn (aq) H+ (aq) + In- (aq) (blue) (yellow) What color will the indicator change when NaOH is added? a. blue b. yellow c. no color change ANS: B OBJ: Identify the effect of base on the equilibrium. TOP: Disturbing a System in Equilibrium: Predictions
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141. Which of the following is the equilibrium expression for the reaction:
2OF2(g)
2F2(g) + O2(g)
a. b. c. d. e. ANS: B OBJ: Determine the equilibrium expression given the balanced equation. TOP: Equilibrium 142. Which of the following is the equilibrium expression for the reaction:
4MnO2(s)
2Mn2O3(s) + O2(g)
a. b. c. d. e. ANS: D OBJ: Determine the equilibrium expression given the balanced equation. TOP: Equilibrium 143. Which of the following is true about a chemical equilibrium? a. It is microscopically static and macroscopically dynamic. b. It is microscopically dynamic and macroscopically static. c. It is microscopically and macroscopically static. d. It is microscopically and macroscopically dynamic. ANS: B OBJ: Identify the correct description of equilibrium. TOP: Equilibrium 144. The reaction between lead ion and chloride ion is: Pb2+(aq) + 2Cl-(aq)
PbCl2(s). If K = 2.57 x 10 for this reaction, what is the value for the equilibrium constant for the reaction: 2PbCl2(s) 2Pb2+(aq) + 4Cl-(aq)? -8 a. 3.89 x 10 b. 6.60 x 1014 c. 1.51 x 10-15 d. 5.07 x 103 e. 1.97 x 10-4 7
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ANS: C OBJ: Determine the equilibrium constant given a change in the reaction stoichiometry. TOP: Variation of Kc with the Form of the Balanced Equation 145. Dinitrogen tetraoxide exists in equilibrium with nitrogen dioxide: N2O4(g)
2NO2(g). At a certain temperature, K = 6.98 x 104. Which of the following statements is true about this reaction? a. the concentration of NO2 is equal to the concentration of N2O4 at equilibrium b. the rate of dissociation of N2O4 is equal to the rate of formation of NO2 at equilibrium c. the reaction will reach equilibrium rapidly d. the rate constant for the forward reaction is equal to the rate constant for the reverse reaction at equilibrium e. two of the above ANS: B OBJ: Identify the correct description of the equilibrium. TOP: Heterogeneous Equilibria
146. Which of the following is the equilibrium expression for the reaction:
NiCO3(s)
Ni2+(aq) + CO32-(aq)?
a. b. c. [Ni2+][CO32-] d. e. [Ni+]2[CO3-]2 ANS: C OBJ: Determine the equilibrium expression given the equilibrium. TOP: Equilibrium 147. The equilibrium constant, K, for the following reaction is 1.96 x 105 at 548K
NH3(g) + HCl(g) NH4Cl (s) Which of the following statements is true about the above reaction? a. The reaction favors the products and the concentrations of NH3 and HCl will be low at equilibrium. b. The reaction favors the reactants and the concentrations of NH3 and HCl will be high at equilibrium c. The reaction favors the product and the equilibrium concentration of NH4Cl equals 1. d. The reaction favors the reactants and the equilibrium concentration of NH4Cl equals 1. e. Two of the above are true. ANS: A OBJ: Identify the correct description of the equilibrium. TOP: Equilibrium
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148. The equilibrium constant, K, for the following reaction is 6.50 x 10-3 at 298K
2NOBr(g) 2NO(g) + Br2(g) If an equilibrium mixture of the three gases in a 5.0L container at 298K contains 0.304mol of NOBr gas and 0.401mol of Br2 gas, what is the equilibrium concentration of NO? a. 6.14 x 10-2 M b. 3.74 x 10-3 M c. 4.93 x 10-3 M d. 1.73 x 10-2 M e. 3.00 x 10-4 M ANS: D OBJ: Calculate the missing equilibrium concentration. TOP: The Equilibrium Constant 149. The equilibrium constant, Kc, for the following reaction is 1.20 x 10-2 at 500K: PCl5(g)
PCl3(g) + Cl2(g). Calculate Kp for this reaction. a. 0.0120 b. 0.492 c. 49.9
d. 20.2
e. 7.13 x 10-6
ANS: B OBJ: Convert Kc to Kp. TOP: Relationship Between Kp and Kc
Use the information below to answer the following questions: For the reaction: CO2(g) + H2(g) H2O(g) + CO(g) At a certain temperature, K = 1.6 x 104.
H = 15.2 kJ/mol
150. If you mixed 5.0 mol CO2, 0.10 mol H2, 3.5 mol of CO, and 0.0010 mol H2O in a one-liter
container, in which direction would the reaction proceed? a. To the left. b. To the right. c. The above mixture is the equilibrium mixture. d. Cannot tell from the information given. ANS: B OBJ: Evaluate the reaction quotient. TOP: The Reaction Quotient 151. Addition of CO to an equilibrium mixture of the above reaction will a. cause [CO2] to increase c. have no effect b. cause [H2O] to increase d. cannot be determined ANS: A OBJ: Predict the effect of added reactant. TOP: Disturbing a System in Equilibrium: Predictions 152. Raising the temperature of the reaction mixture will: a. cause [CO2] to increase c. have no effect b. cause [H2O] to increase d. cannot be determined ANS: B OBJ: Predict the effect of increased temperature on the equilibrium. TOP: Evaluation of Equilibrium Constants at Different Temperatures
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CONCEPTUAL 1. Compare the situation of a crowded nightclub at capacity with a waiting line to equilibrium. What could change this equilibrium condition? OBJ: Relate equilibrium to a crowded nightclub with a waiting line. TOP: The Equilibrium Constant 2. A chemical engineer will use knowledge of a reaction in design of a chemical plant. Name at least four important pieces of information that the engineer would want to know about a reaction to maximize the yield of product. OBJ: Identify the chemical information important in maximizing reaction yield. TOP: Reaction Yield 3. Catalysts have no effect on the position of equilibrium. Why are they used in almost every industrial chemical equilibrium reaction? OBJ: Explain the importance of catalysts in industrial processes. TOP: Catalysts 4. Why would describing a reaction that has G > +200 kJ/mol or G < 200 kJ/mol as an equilibrium reaction not be meaningful? OBJ: Explain why the term equilibrium does not really to all reactions. TOP: Relationship Between Delta G° rxn and the Equilibrium Constant 5. List three reactions found in everyday life that are equilibrium reactions. What factors routinely affect the equilibrium concentrations of those reactions? OBJ: List three equilibrium reactions associated with daily life and describe the factors that effect equilibration. TOP: Equilibrium
Chapter 18—Ionic Equilibria I: Acids and Bases MULTIPLE CHOICE Chapter 18 Values The following values will be useful for the problems in this chapter. Acid
K
Substance or Species
K
HF HNO2 CH3COOH HOCl HOBr HOCN HCN H2SO4
Ka = 7.2 104 Ka = 4.5 104 Ka = 1.8 105 Ka = 3.5 108 Ka = 2.5 109 Ka = 3.5 104 Ka = 4.0 1010 Ka1 = very large Ka2 = 1.2 102
NH3 (CH3)3N [Co(OH2)6]2+ [Fe(OH2)6]2+ [Fe(OH2)6]3+ [Be(OH2)4]2+ [Cu(OH2)4]2+ HBO2 (COOH)2
Kb = 1.8 105 Kb = 7.4 105 Ka = 5.0 1010 Ka = 3.0 1010 Ka = 4.0 103 Ka = 1.0 105 Ka = 1.0 108 Ka = 6.0 1010 Ka1 = 5.9 102
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H2CO3
Ka1 = 4.2 107 Ka2 = 4.8 1011
CH3NH2
Ka2 = 6.4 105 Kb = 5.0 104
1. Which one of the following is a weak acid? a. H2SO4 b. HI c. HBr d. HF e. HClO4 ANS: D OBJ: Identify the weak acid formula. TOP: Review of Strong Electrolytes 2. Which of the following is a strong acid? a. HNO2 b. HClO2 c. HBrO d. HClO3 e. H2SO3 ANS: D OBJ: Identify the strong acid formula. TOP: Review of Strong Electrolytes 3. Of the following, which acids are weak acids? I. HBr II. HF III. HNO3 IV. HNO2 V. H2CO3 VI. H3PO4
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a. b. c. d. e.
I, II, and III II, IV, V, and VI I, II, and V IV, V, and VI another combination
ANS: B OBJ: Identify the weak acid formulas. TOP: Review of Strong Electrolytes 4. Which of the following is a soluble, strong base? a. Sr(OH)2 b. NH2OH c. Fe(OH)3 d. Cr(OH)3 e. Be(OH)2 ANS: A OBJ: Identify the strong base formula. TOP: Review of Strong Electrolytes 5. Which of the following is not a soluble base? a. Sr(OH)2 b. NaOH c. KOH d. Mn(OH)2 e. CsOH ANS: D OBJ: Identify the formula of an insoluble base. TOP: Review of Strong Electrolytes 6. Which one of the following is an insoluble base? a. Ca(OH)2 b. Sr(OH)2 c. Ba(OH)2 d. Cu(OH)2 e. CsOH ANS: D OBJ: Identify the formula of an insoluble base. TOP: Review of Strong Electrolytes 7. Which one of the following salts is soluble in water? a. AgCl b. NaClO3 c. BaSO4 d. FeS e. CaCO3 ANS: B OBJ: Identify the strong electrolyte. TOP: Review of Strong Electrolytes Whitten 10e
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8. Which one of the following salts is insoluble in water? a. CrCl3 b. AgF c. PbSO4 d. Mn(NO3)2 e. Cu(ClO4)2 ANS: C OBJ: Identify the insoluble salt. TOP: Review of Strong Electrolytes 9. Which one of the following salts is insoluble in water? a. Ba(CH3COO)2 b. BaCl2 c. CaCl2 d. Ca(NO3)2 e. Ca3(PO4)2 ANS: E OBJ: Identify the insoluble salt. TOP: Review of Strong Electrolytes 10. Which salt is produced from a strong acid and a strong base? a. LiF b. NaBrO c. NH4NO3 d. NaHCO3 e. NaCl ANS: E OBJ: Identify the product of a strong acid-strong base reaction. TOP: Review of Strong Electrolytes 11. Which term is not correctly matched with its description? a. weak acid / partially ionized b. salt / cation of an acid, anion of a base c. strong soluble base / soluble metal hydroxide d. weak base / accepts H+ from an acid e. strong electrolyte / strong acid, strong base, or soluble salt ANS: B OBJ: Identify the incorrect description of an aqueous chemistry term. TOP: Review of Strong Electrolytes 12. Which one of the following substances is not a strong electrolyte? a. NH4Cl b. H2SO4 c. HNO3 d. NH3 e. Mg(NO3)2 ANS: D OBJ: Identify the species that is not a strong electrolyte. TOP: Review of Strong Electrolytes
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13. Which one of the following is a soluble strong electrolyte? a. HNO2 b. H2CO3 c. Ca(OH)2 d. Mg(OH)2 e. BaCO3 ANS: C OBJ: Identify the strong electrolyte. TOP: Review of Strong Electrolytes 14. The molar concentration of the Ca2+ ion is ____ and the molar concentration of OH ion is ____ in 0.015 M calcium hydroxide. a. 0.015 M; 0.015 M b. 0.015 M; 0.030 M c. 0.030 M; 0.015 M d. 0.030 M; 0.030 M e. not enough information to calculate ANS: B OBJ: Calculate the molarity of each ion given the concentration of compound. TOP: Review of Strong Electrolytes 15. Each response gives a pair of solutions. Which pair of solutions should conduct electrical current equally well because they contain equal numbers of ions? a. 0.10 M NH3 and 0.10 M NH4Cl b. 0.10 M HBr and 0.10 M HF c. 0.10 M NaCl and 0.10 M Na2SO4 d. 0.10 M NaNO3 and 0.10 M HNO3 e. 0.10 M HNO3 and 0.10 M HNO2 ANS: D OBJ: Identify the solutions which contain equal numbers of ions. TOP: Review of Strong Electrolytes 16. Which electrolyte is not correctly matched? a. KClO3 / soluble salt b. HCN / weak base c. Ba(OH)2 / strong soluble base d. HNO3 / strong acid e. (NH4)2SO4 / soluble salt ANS: B OBJ: Identify the incorrect classification. TOP: Review of Strong Electrolytes 17. In a sample of pure water, only one of the following statements is always true at all conditions of temperature and pressure. Which one is always true? a. [H3O+] = 1.0 107 M b. [OH] = 1.0 107 M c. pH = 7.0 d. pH + pOH = 14.0 e. [H3O+] = [OH]
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ANS: E OBJ: Identify the equality that is always true for pure water. TOP: The Autoionization of Water 18. If additional OH is added to a sample of pure water, which of the following statements is incorrect? a. The equilibrium position shifts to the left. b. The solution becomes more basic. c. The [H3O+] remains unchanged. d. The [OH] > [H3O+]. e. The amount of non-ionized H2O increases. ANS: C OBJ: Identify the incorrect description of the effect of hydroxide ion on pure water. TOP: The Autoionization of Water 19. Which of the following relationships in incorrect? Assume 25C. a. pH + pOH = 14.00 b. [OH] = 10pOH c. pKW = log KW d. [OH] [H3O+] = 1.0 1014 e. pH = log [H3O+] ANS: B OBJ: Identify the incorrect equation describing pH, pOH, or Kw. TOP: The Autoionization of Water 20. Which solution would have the lowest [OH]? a. pure water b. 0.50 M NH3 c. 0.50 M HCl d. 0.10 M NaOH e. 0.10 M NaCl ANS: C OBJ: Identify the solution with the lowest hydroxide ion concentration. TOP: The Autoionization of Water 21. Calculate the concentrations of H3O+ and OH ions in a 0.25 M HClO4 solution. a. [H3O+] = 0.25 M; [OH] = 0.25 M b. [H3O+] = 0.25 M; [OH] = 4.0 M c. [H3O+] = 0.25 M; [OH] = 4.0 1014 M d. [H3O+] = 0.50 M; [OH] = 2.0 1014 M e. [H3O+] = 1.0 107 M; [OH] = 1.0 107 M ANS: C OBJ: Calculate the concentrations of hydronium and hydroxide ions in a solution of strong acid. TOP: The Autoionization of Water 22. Calculate the concentrations of H3O+ and OH ions in a 0.050 M Ba(OH)2 solution. a. [H3O+] = 0.050 M; [OH] = 0.050 M b. [H3O+] = 1.0 107 M; [OH] = 0.10 M c. [H3O+] = 2.0 1013 M; [OH] = 0.050 M d. [H3O+] = 1.0 1013 M; [OH] = 0.10 M e. [H3O+] = 0.10 M; [OH] = 1.0 1013 M Whitten 10e
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ANS: D OBJ: Calculate the concentrations of hydronium and hydroxide ions in a solution of strong base. TOP: The Autoionization of Water 23. At 60C, Kw = 9.6 1014. What are the concentrations of the H3O+ and OH ions in pure water that is neutral at 60C? a. [H3O+] = [OH] = 4.8 1014 b. [H3O+] = [OH] = 4.8 107 c. [H3O+] = [OH] = 3.1 107 d. [H3O+] = [OH] = 1.0 107 e. [H3O+] = 1.0 107; [OH] = 9.6 107 ANS: C OBJ: Calculate the concentrations of hydronium and hydroxide ions in pure water, given Kw. TOP: The Autoionization of Water 24. A solution having a pH of 1.4 would be described as ____. a. distinctly basic b. slightly basic c. neutral d. slightly acidic e. distinctly acidic ANS: E OBJ: Approximate the acidity or basicity of a solution based on its pH. TOP: The pH and pOH Scales 25. A solution in which the pOH is 12.5 would be described as ____. a. distinctly basic b. slightly basic c. neutral d. slightly acidic e. distinctly acidic ANS: E OBJ: Approximate the acidity or basicity of a solution based on its pOH. TOP: The pH and pOH Scales 26. Which pH or pOH value is incorrectly matched with its description? a. pH = 1.32 / distinctly acidic b. pOH = 13.8 / distinctly basic c. pOH = 7.8 / slightly acidic d. pH = 12.5 / distinctly basic e. pH = 6.7 / slightly acidic ANS: B OBJ: Identify the incorrect approximation of acidity or basicity of a solution pH or pOH. TOP: The pH and pOH Scales
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27. Calculate the pH of a solution that has the H3O+ concentration of 0.50 M. a. 0.30 b. 13.70 c. 0.30 d. 7.30 e. 0.50 ANS: C OBJ: Calculate pH given the hydronium ion concentration. TOP: The pH and pOH Scales 28. Calculate the pOH of a solution that has the OH concentration of 0.50 M. a. 0.50 b. 14.30 c. 6.70 d. 13.70 e. 0.30 ANS: E OBJ: Calculate pOH given the hydroxide ion concentration. TOP: The pH and pOH Scales 29. Calculate the pH of a solution in which [OH] = 2.50 104 M. a. 0.40 b. 3.60 c. 3.60 d. 10.40 e. 13.60 ANS: D OBJ: Calculate pH given the hydroxide ion concentration. TOP: The pH and pOH Scales 30. What is the pOH of a solution in which [H3O+] = 3.60 1010 M? a. 8.56 b. 5.44 c. 9.44 d. 4.56 e. 4.32 ANS: D OBJ: Calculate pOH given the hydronium ion concentration. TOP: The pH and pOH Scales 31. What is the concentration of H3O+ ions in a solution in which pH = 4.32? a. 4.8 105 M b. 6.2 104 M c. 5.1 104 M d. 8.6 105 M e. 3.5 104 M ANS: A OBJ: Calculate hydronium ion concentration given pH. TOP: The pH and pOH Scales
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32. The pH of a solution is 0.38. What is the concentration of H3O+ ions in this solution? a. 2.4 M b. 0.42 M c. 0.42 M d. 4.2 107 M e. 11.6 M ANS: A OBJ: Calculate hydronium ion concentration given pH. TOP: The pH and pOH Scales 33. What is the hydrogen ion concentration in a solution having a pOH of 3.62? a. 2.6 1011 M b. 4.2 1011 M c. 3.8 104 M d. 3.8 104 M e. 5.1 1010 M ANS: B OBJ: Calculate hydronium ion concentration given pOH. TOP: The pH and pOH Scales 34. What is the pOH of 0.013 M HBr solution? a. 9.66 b. 0.013 c. 1.89 d. 4.34 e. 12.11 ANS: E OBJ: Calculate the pOH given the molarity of a strong acid. TOP: The pH and pOH Scales 35. What is the pH of a 0.400 M HNO3 solution? a. 0.40 b. 2.05 c. 0.60 d. 4.12 e. 1.67 ANS: A OBJ: Calculate pH given the molarity of a strong acid. TOP: The pH and pOH Scales 36. Calculate the pH in a 0.025 M Ca(OH)2 solution. a. 12.70 b. 12.40 c. 1.30 d. 1.60 e. No way to calculate without Kb ANS: A OBJ: Calculate pH given the molarity of a strong base. TOP: The pH and pOH Scales
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37. Calculate the pH of 0.075 M NaOH. a. 10.40 b. 11.12 c. 11.46 d. 12.88 e. 13.26 ANS: D OBJ: Calculate pH given the molarity of a strong base. TOP: The pH and pOH Scales 38. What is the pH of 400. mL of solution containing 0.0112 gram of HNO3? a. 4.15 b. 3.35 c. 10.65 d. 3.75 e. 2.95 ANS: B OBJ: Calculate pH given the mass of strong acid and volume of solvent. TOP: The pH and pOH Scales 39. What is the pH of 500. mL of solution containing 0.0124 gram of Ca(OH)2? a. 2.96 b. 3.17 c. 9.68 d. 10.83 e. 11.04 ANS: D OBJ: Calculate pH given the mass of strong base and volume of solvent. TOP: The pH and pOH Scales 40. How many milligrams of HCl are contained in a 250. mL sample of a solution of hydrochloric acid with pH = 3.15? a. 6.46 mg b. 25.8 mg c. 103 mg d. 2.83 mg e. 0.177 mg ANS: A DIF: Harder Question OBJ: Calculate mass of strong acid given the pH and volume of solvent. TOP: The pH and pOH Scales 41. The pH of a solution of hydrochloric acid is 2.80. What is the molarity of the acid? a. 6.3 103 M b. 4.2 103 M c. 1.6 103 M d. 6.3 102 M e. 4.2 102 M
Whitten 10e
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653
ANS: C OBJ: Calculate molarity given pH. TOP: The pH and pOH Scales 42. The pH of a solution of Ba(OH)2 is 9.40. What is the molarity of this solution of base? a. 1.3 105 M b. 1.8 105 M c. 6.0 104 M d. 8.3 104 M e. 2.5 105 M ANS: A OBJ: Calculate molarity given pH. TOP: The pH and pOH Scales 43. If enough base is added to a solution to cause the pH to increase from 7.0 to 9.0, the ____. a. [OH] increases by a factor of 100 b. [OH] increases by a factor of 0.010 c. [OH] increases by 2 M d. [OH] increases by a factor of 9/7 e. [OH] increases by a factor of 2 ANS: A OBJ: Calculate the change in concentration given the change in pH. TOP: The pH and pOH Scales 44. Which of the following statements about measurement of pH is incorrect? a. The pH of a solution can be determined using a pH meter. b. The pH of a solution can be determined by the indicator method. c. A pH meter is more accurate than an indicator for determining the pH. d. Many indicators are strong acids or strong bases. e. Acid-base indicators have different colors in solutions of different pH. ANS: D OBJ: Identify the incorrect description of pH measurement. TOP: The pH and pOH Scales 45. For a given weak acid, HA, the value of Ka ____. a. will change with pH b. cannot be less than 107 c. cannot be greater than 107 d. does not change with temperature e. is calculated from experimental data ANS: E OBJ: Identify the best description of Ka. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
Whitten 10e
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46. In a solution containing only a weak monoprotic acid HA, [H3O+] is ____ [A]; if the solution is not very dilute, the concentration of nonionized HA is approximately equal to the ____ of the solution. a. greater than; molarity b. less than; molarity c. equal to; pH d. equal to; molarity e. less than; pH ANS: D OBJ: Identify the best words to complete the description of weak acid ionization. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 47. Which of the following statements about weak acids is false? a. Weak acids ionize only slightly in dilute aqueous solution. b. The Ka values for weak acids are equal to the pH for dilute solutions. c. Weak acids are much more numerous than strong acids. d. Many weak acids are familiar to us in everyday use. e. The ionization constant for a weak acid does not include a term for the concentration of water. ANS: B OBJ: Identify the incorrect description of weak acids. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 48. Consider calculations of [H3O+] in each of the following solutions. Do not go through the calculations. For which calculation is it not reasonable to assume that "x" is much less than the initial concentration? The x represents concentration ionized. a. 0.20 M H2O2 Ka = 2.4 1012 b. 0.010 M HCN Ka = 4.0 1010 c. 0.010 M H2S Ka1 = 1.0 107, Ka2 = 1.0 1019 d. 1.00 M NH3 Kb = 1.8 105 e. 0.010 M (COOH)2 Ka1 = 5.9 102, Ka2 = 6.4 105 ANS: E OBJ: Identify the weak acid whose pH must be solved without assumptions. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 49. We make a 1.0 M solution of an unknown acid, HX. With a pH meter, we determine that the pH of the solution is 5.00. Which of the following statements about the HX is true? a. HX is a strong acid. b. HX is a weak acid with a Ka value of about 105. c. HX is a weak acid with a Ka value of about 108. d. HX is a weak acid with a Ka value of about 1010. e. HX would probably be a good acid-base indicator. ANS: D OBJ: Approximate acidity and Ka given molarity and pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
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655
50. Dichloroacetic acid is a weak monoprotic acid. A 0.100 M solution of this acid has [H3O+] = 0.0070 M. What is the value of Ka for Cl2HCCOOH? The reaction is Cl2HCCOOH + H2O H3O+ + Cl2HCCOO a. b. c. d. e.
1.8 103 5.3 104 7.5 103 1.9 103 11.6
ANS: B OBJ: Calculate Ka given an acid molarity and hydronium ion concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 51. The [H3O+] = 2.0 104 M for a 0.020 M solution of a weak acid. Calculate the pKa for this acid. a. 1.70 b. 3.70 c. 2.00 d. 5.70 e. 4.69 ANS: D OBJ: Calculate pKa given an acid molarity and hydronium ion concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 52. Calculate the ionization constant for a weak acid, HA, that is 1.60% ionized in 0.0950 M solution. a. 2.69 103 b. 3.77 102 c. 9.91 106 d. 1.63 102 e. 2.47 105 ANS: E OBJ: Calculate Ka given an acid molarity and % ionization. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 53. Calculate the pKa for a weak acid, HA, that is 2.3% ionized in 0.080 M solution? a. 4.37 b. 4.71 c. 1.66 d. 2.33 e. 3.09 ANS: A OBJ: Calculate pKa given an acid molarity and % ionization. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 54. The pH of a 0.10 M solution of a monoprotic acid is 2.85. What is the value of the ionization constant of the acid? a. 6.3 105 b. 3.8 106 c. 2.0 105 d. 4.0 108 e. 7.2 106 Whitten 10e
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656
ANS: C OBJ: Calculate Ka given the pH and acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 55. The pH of a 0.20 M solution of a weak monoprotic acid is 3.70. What is the value of the ionization constant for the acid? a. 7.0 104 b. 4.0 106 c. 2.0 107 d. 1.8 105 e. 6.1 105 ANS: C OBJ: Calculate Ka given the pH and acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 56. The pH of a weak monoprotic acid (HA) is 3.75. If the ionization constant for this acid is 8.9 106, what is the concentration of the weak acid? a. 0.890 M b. 5.05 M c. 0.0500 M d. 0.00355 M e. 0.00712 M ANS: D OBJ: Calculate the acid concentration given the pH and Ka. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 57. The ionization constant for the hypothetical weak acid, HA, is 1.0 105. What is the equilibrium concentration of [H3O+] in 0.20 M HA solution? a. 4.3 103 M b. 8.1 104 M c. 1.4 103 M d. 1.0 105 M e. 5.0 104 M ANS: C OBJ: Calculate the hydronium ion concentration given Ka and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 58. Calculate the [H3O+] in 0.010 M HOCl solution. Ka = 3.5 108 a. 1.9 105 M b. 3.6 105 M c. 5.8 105 M d. 4.0 106 M e. 7.2 106 M ANS: A OBJ: Calculate the hydronium ion concentration given Ka and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 59. Calculate the value of [H3O+] in a 0.010 M HOBr solution. Ka = 2.5 109 a. 5.0 106 M b. 5.0 105 M Whitten 10e
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657
c. 2.5 107 M d. 2.5 1011 M e. 5.0 107 M ANS: A OBJ: Calculate the hydronium ion concentration given Ka and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 60. Calculate the pH of 0.10 M HCN solution. Ka = 4.0 1010 a. 6.75 b. 5.20 c. 8.42 d. 9.52 e. 10.4 ANS: B OBJ: Calculate pH given the Ka and acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 61. Calculate the pH of 0.050 M benzoic acid solution. Ka = 6.3 105 a. 4.20 b. 1.45 c. 5.50 d. 2.75 e. 2.10 ANS: D OBJ: Calculate pH given the Ka and acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 62. What is the [OH] in a 0.25 M hypobromous acid (HOBr) solution? Ka = 2.5 109 a. 4.0 1010 M b. 2.5 109 M c. 1.0 107 M d. 2.5 105 M e. 2.0 1010 M ANS: A OBJ: Calculate the hydroxide ion concentration given Ka and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 63. What is the [OCl] in 0.10 M hypochlorous acid, HOCl? Ka = 3.5 108 a. 5.9 105 M b. 8.4 104 M c. 6.1 104 M d. 4.2 106 M e. 3.6 107 M ANS: A OBJ: Calculate the conjugate base concentration given Ka and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
Whitten 10e
Test Bank
658
64. What is the value of [OH] in a 0.015 M CH3COOH solution? Ka = 1.8 105 a. 1.9 1011 M b. 2.0 106 M c. 1.0 109 M d. 5.0 108 M e. 5.0 107 M ANS: A OBJ: Calculate the hydroxide ion concentration given Ka and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 65. The pH of a 0.100 M solution of a weak acid, HA, is 3.50. Calculate the percent ionization of the acid in 0.100 M solution. a. 0.016% b. 0.078% c. 0.32% d. 0.68% e. 1.6% ANS: C OBJ: Calculate the % ionization given pH and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 66. What is the percent ionization of 0.20 M HNO2? Ka = 4.5 104 a. 1.0% b. 2.8% c. 4.6% d. 5.3% e. 5.9% ANS: C OBJ: Calculate the % ionization given pH and the acid concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 67. Calculate the pH of a solution of acetic acid that is 3.0% ionized. Ka = 1.8 105 a. 2.64 b. 3.24 c. 2.94 d. 4.99 e. 4.70 ANS: B DIF: Harder Question OBJ: Calculate pH given the acid Ka and % ionization. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 68. How many moles of nitrous acid, HNO2, are required initially to prepare 2.5 liters of a solution of pH = 3.00? Ka = 4.5 104 a. 1.8 104 mol b. 6.2 102 mol c. 1.7 104 mol d. 3.6 104 mol e. 8.0 103 mol
Whitten 10e
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ANS: E DIF: Harder Question OBJ: Calculate the moles weak acid required to obtain a specific volume and pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 69. Assume that five weak acids, identified only by numbers (I, II, III, IV, and V), have the following ionization constants. Acid I. II. III. IV. V.
Ionization Constant (Ka value) 5.0 103 3.0 105 2.6 107 4.0 109 7.3 1011
A 0.10 M solution of which acid would have the highest pH? a. I b. II c. III d. IV e. V ANS: E OBJ: Identify the Ka which will result in the highest solution pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 70. Assume that five weak acids, identified only by numbers (I, II, III, IV, and V), have the following ionization constants. Acid I. II. III. IV. V.
Ionization Constant (Ka value) 1.0 103 3.0 105 2.6 107 4.0 109 7.3 1011
The anion of which acid is the weakest base? a. I b. II c. III d. IV e. V ANS: A OBJ: Identify the Ka of the acid with the weakest conjugate base. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
Whitten 10e
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660
71. The [OH] = 1.3 106 M for a 0.025 M solution of a weak base. Calculate the value of Kb for this weak base. a. 5.2 105 b. 3.1 107 c. 7.7 109 d. 4.0 108 e. 6.8 1011 ANS: E OBJ: Calculate Kb given a base molarity and hydroxide ion concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 72. The pH of a 0.12 M solution of a weak base is 10.30. What is the value of pKb for this weak base? a. 3.70 b. 6.48 c. 10.30 d. 5.44 e. 4.49 ANS: B OBJ: Calculate pKb given a base molarity and pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 73. Calculate the pH of a 0.10 M solution of aqueous ammonia. Kb = 1.8 105 a. 9.36 b. 10.89 c. 11.11 d. 12.00 e. 2.89 ANS: C OBJ: Calculate pH given a base molarity and Kb. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 74. Calculate the value of [H3O+] in a 0.25 M solution of aqueous ammonia. Kb = 1.8 105 a. 2.1 103 M b. 4.7 1012 M c. 2.3 109 M d. 4.3 1010 M e. 2.4 1011 M ANS: B OBJ: Calculate the hydronium ion concentration given a base molarity and Kb. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 75. Calculate the value of [H3O+] in a 0.18 M solution of aqueous aniline. Kb = 4.2 1010 a. 1.2 109 M b. 8.7 106 M c. 2.0 105 M d. 1.0 107 M e. 4.2 1010 M
Whitten 10e
Test Bank
661
ANS: A OBJ: Calculate the hydronium ion concentration given a base molarity and Kb. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 76. Trimethylamine ionizes as follows in water. What concentration of trimethylammonium ion, (CH3)3NH+, is present in 9.0 102 M (CH3)3N? Kb = 7.4 105 (CH3)3N + H2O (CH3)3NH+ + OH a. b. c. d. e.
1.6 104 M 5.2 103 M 3.8 104 M 2.6 103 M 2.7 105 M
ANS: D OBJ: Calculate the conjugate acid concentration given a base molarity and Kb. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 77. What is the percent ionization for a 1.0 103 M solution of pyridine? Kb = 1.5 109 a. 0.12% b. 1.6% c. 2.8% d. 0.045% e. 0.67% ANS: A OBJ: Calculate the % ionization given Kb and the base concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 78. Calculate the pH of a 0.050 M solution of hydroxylamine, NH2OH. Kb = 6.6 109 a. 9.91 b. 9.48 c. 9.26 d. 10.56 e. 8.61 ANS: C OBJ: Calculate pH given a base molarity and Kb. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 79. Which answer includes all of the following true statements about 0.10 M H3PO4 solution? I. The species present in highest concentration is nonionized H3PO4. II. The species present in highest concentration is H2PO4 ion. III. The species present in lowest concentration is PO43 ion. IV. Ka2 > Ka3 a. b. c. d. e.
I and IV II and IV I and III II and III I, III and IV
Whitten 10e
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662
ANS: A OBJ: Identify the correct descriptions of a weak acid solution.
TOP: Polyprotic Acids
80. Which of the following statements about polyprotic acids is incorrect? a. Polyprotic acids can furnish two or more hydronium ions per molecule. b. It is generally accepted practice to ignore second or third ionizations when calculating the concentration of H3O+. c. The ionizations of polyprotic acids occur simultaneously. d. Successive ionization constants for polyprotic acids generally decrease. e. Phosphoric acid is a typical polyprotic acid. ANS: C OBJ: Identify the incorrect description of a polyprotic acid. TOP: Polyprotic Acids 81. Which response lists the species present in the highest concentration in a solution of 0.20 M H3PO4? a. H3PO4, H2PO4, HPO42 b. H2PO4, HPO42, PO43 c. H3PO4, H3O+, OH d. HPO42, PO43, OH e. H3PO4, H2PO4, H3O+ ANS: E OBJ: Identify the highest concentration species in a polyprotic acid solution. TOP: Polyprotic Acids 82. Consider a solution that is 0.10 M in a weak triprotic acid that is represented by the general formula H3A with the following ionization constants. For H3A: Ka1 = 1.0 103, Ka2 = 1.0 108, Ka3 = 1.0 1012 What is the concentration of HA2? a. 4.5 103 M b. 1.0 104 M c. 3.2 105 M d. 1.0 108 M e. 6.2 107 M ANS: D OBJ: Calculate the concentration of monoprotic acid in a solution of a triprotic acid. TOP: Polyprotic Acids 83. Calculate the pH of a 0.10 M solution of a hypothetical triprotic acid H3A, with Ka1 = 6.0 103, Ka2 = 2.0 108, and Ka3 = 1.0 1014. a. 1.48 b. 1.61 c. 1.66 d. 1.84 e. 2.06 ANS: C OBJ: Calculate the pH of a solution of triprotic acid. TOP: Polyprotic Acids
Whitten 10e
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84. What is the concentration of A3 ions at equilibrium for a 0.10 M solution of a hypothetical triprotic acid H3A, with Ka1 = 6.0 103, Ka2 = 2.0 108, and Ka3 = 1.0 1014? a. 9.1 1021 M b. 6.2 1018 M c. 3.1 1015 M d. 1.0 1014 M e. 4.8 1019 M ANS: A OBJ: Calculate the concentration of the nonprotonated anion in a solution of a triprotic acid. TOP: Polyprotic Acids 85. The hypothetical weak acid H2A ionizes as shown below. Calculate the [HA] in 0.20 M H2A. H2A H+ + HA Ka1 = 1.0 107 + 2 HA H +A Ka2 = 5.0 1011 a. b. c. d. e.
6.3 105 M 1.0 107 M 3.0 104 M 2.2 106 M 1.4 104 M
ANS: E OBJ: Calculate the concentration of monoprotic acid in a solution of diprotic acid. TOP: Polyprotic Acids 86. The hypothetical weak acid H2A ionizes as shown below. Calculate the [A2] in 0.20 M H2A. H2A H+ + HA Ka1 = 1.0 107 HA H+ + A2 Ka2 = 5.0 1011 a. b. c. d. e.
1.0 107 M 5.8 1014 M 5.0 1011 M 4.6 1013 M 3.8 1018 M
ANS: C OBJ: Calculate the concentration of nonprotonated acid in a solution of diprotic acid. TOP: Polyprotic Acids 87. Calculate the pH of 3.2 103 M H2CO3 solution. a. 4.09 b. 4.30 c. 4.44 d. 4.94 e. 5.56 ANS: C OBJ: Calculate the pH given the diprotic acid molarity. TOP: Polyprotic Acids
Whitten 10e
Test Bank
664
88. What is the [OH] in 0.20 M oxalic acid, (COOH)2, solution? a. 4.1 1010 M b. 7.4 1011 M c. 1.2 1013 M d. 3.2 1012 M e. 3.8 1012 M ANS: C OBJ: Calculate hydroxide ion concentration given the diprotic acid molarity. TOP: Polyprotic Acids 89. Calculate the [SO42] in 0.20 M H2SO4. a. 4.3 102 M b. 8.4 102 M c. 1.1 102 M d. 6.4 101 M e. 2.5 101 M ANS: C OBJ: Calculate the nonprotonated anion concentration given diprotic acid molarity. TOP: Polyprotic Acids 90. Which of the following anions is the strongest base? a. ClO b. ClO3 c. ClO4 d. Cl e. I ANS: A OBJ: Identify the strongest conjugate base. TOP: Solvolysis 91. Which of the following has the strongest conjugate base? a. HNO3 b. HF c. HBr d. HCl e. H2SO4 ANS: B OBJ: Identify the strongest conjugate base of the listed acids. TOP: Solvolysis 92. Which of the following statements is false? a. Solvolysis is the reaction of a substance with the solvent in which it is dissolved. b. Hydrolysis is the reaction of a substance with water. c. The anion of a weak acid reacts with water to form nonionized acid and OH ions. d. According to Brønsted-Lowry the anions of strong acids are very strong bases. e. The conjugate acid of a strong base is a very weak acid. ANS: D OBJ: Identify the incorrect description of acid-base chemistry and terms. TOP: Solvolysis Whitten 10e
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665
93. Which one of the following salts produces neutral solutions when it is dissolved in water? a. NaCN b. NaOCl c. NaF d. NaBr e. NaCH3COO ANS: D OBJ: Identify the neutral salt. TOP: Salts of Strong Bases and Strong Acids 94. Which one of the following salts produces neutral solutions when it is dissolved in water? a. NH4F b. LiOCl c. BaBr2 d. CaSO3 e. (NH4)2SO4 ANS: C OBJ: Identify the neutral salt. TOP: Salts of Strong Bases and Strong Acids 95. Which one of the following salts does not give a neutral solution when it is dissolved in water? a. KNO3 b. BaCl2 c. Ca(ClO3)2 d. NH4OH e. NaBr ANS: D OBJ: Identify the acidic or basic salt. TOP: Salts of Strong Bases and Strong Acids 96. Which of the following acid / base pairs produce neutral salts when they react? a. HClO4 / Ba(OH)2 b. HF / KOH c. HBr / LiOH d. Both (a) and (c). e. All of these choices. ANS: D OBJ: Identify the acid-base reactants which produce a neutral salt. TOP: Salts of Strong Bases and Strong Acids 97. When salts derived from ____ acids and ____ bases are dissolved in water, the resulting solution is always acidic. a. strong; strong b. strong; weak c. weak; strong d. weak; weak e. no way to determine without Ka and Kb ANS: B OBJ: Identify the acid-base combination that produces acidic salts. TOP: Salts of Strong Bases and Weak Acids Whitten 10e
Test Bank
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98. Which one of the following salts produces basic solutions when it is dissolved in water? a. NaNO3 b. NH4OCl c. NH4Br d. NH4I e. KCl ANS: B OBJ: Identify the basic salt. TOP: Salts of Strong Bases and Weak Acids 99. The value of Ka for benzoic acid, C6H5COOH, is 6.3 105. When sodium benzoate is dissolved in water, the reaction that occurs is ____, resulting in a solution that is ____. a. Na+ + C6H5COO NaC6H5COO; neutral b. C6H5COO + H2O H3O+ + C6H4COO2; acidic c. C6H5COOH + H2O H3O+ + C6H5COO; acidic d. No reaction; neutral e. C6H5COO + H2O CH6H5COOH + OH; basic ANS: E OBJ: Deduce the balanced reaction and solution acidity from the Ka and formula of an acid. TOP: Salts of Strong Bases and Weak Acids 100. When solid NH4NO3 is added to water, the pH ____. a. remains at 7 b. becomes greater than 7 c. becomes less than 7 d. is independent of the amount dissolved e. Can not be determined ANS: C OBJ: Describe the pH of a salt solution. TOP: Salts of Strong Bases and Weak Acids 101. Which one of the following salts produces basic solutions when it is dissolved in water? a. NH4NO3 b. NaBr c. NaF d. NaNO3 e. NaI ANS: C OBJ: Identify the basic salt. TOP: Salts of Strong Bases and Weak Acids 102. Which of the following acid / base pairs produce basic salts when they react? a. HCN / Ca(OH)2 b. H2SO4 / LiOH c. HCl / NaOH d. Both (a) and (b). e. None of these choices. ANS: A OBJ: Identify the acid-base reactants which produce a basic salt. TOP: Salts of Strong Bases and Weak Acids Whitten 10e
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103. A 0.10 M solution of which of the following salts is most basic? a. NaF b. NaNO2 c. NaCH3COO d. NaOCl e. NaCN ANS: E DIF: Harder Question OBJ: Identify the most basic salt. TOP: Salts of Strong Bases and Weak Acids 104. A 0.10 M solution of which of the following would be most basic? a. RbI b. NH4NO3 c. KCH3COO d. NaCN e. BaCl2 ANS: D DIF: Harder Question OBJ: Identify the most basic salt. TOP: Salts of Strong Bases and Weak Acids 105. Calculate the (base) hydrolysis constant for the hypochlorite ion, OCl. a. 3.5 108 b. 1.8 105 c. 5.6 1010 d. 2.9 107 e. 3.5 106 ANS: D OBJ: Determine Kb of an anion. TOP: Salts of Strong Bases and Weak Acids 106. Evaluate the (base) hydrolysis constant for sodium cyanate, NaOCN. a. 3.7 1012 b. 6.4 109 c. 2.9 1011 d. 4.0 1010 e. 6.8 1010 ANS: C OBJ: Determine Kb of an anion. TOP: Salts of Strong Bases and Weak Acids 107. What is the value of the (base) hydrolysis constant for NaNO2, sodium nitrite? Ka = 4.5 104 for HNO2. a. 4.5 104 b. 2.2 1011 c. 4.5 1018 d. 4.5 1010 e. 2.1 109
Whitten 10e
Test Bank
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ANS: B OBJ: Determine Kb given Ka. TOP: Salts of Strong Bases and Weak Acids 108. Calculate the acid ionization constant of an unknown monoprotic weak acid, HA, if its salt, NaA, has a (base) hydrolysis constant of 6.2 109. a. 6.0 107 b. 1.6 106 c. 4.5 107 d. 5.6 108 e. 4.3 106 ANS: B DIF: Harder Question OBJ: Calculate Ka given Kb. TOP: Salts of Strong Bases and Weak Acids 109. Calculate the pH of 0.14 M NaF solution. a. 8.09 b. 8.12 c. 8.14 d. 8.18 e. 8.21 ANS: C OBJ: Calculate pH given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids 110. What is the pH of 0.35 M KOBr solution? a. 8.60 b. 9.06 c. 11.07 d. 11.53 e. 13.54 ANS: C OBJ: Calculate pH given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids 111. What is the pH of 0.51 M Ca(CH3COO)2 solution? a. 11.1 b. 9.22 c. 9.38 d. 10.7 e. 4.77 ANS: C OBJ: Calculate pH given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids
Whitten 10e
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112. Calculate the pH of 0.10 M solution of NaBO2. a. 9.84 b. 12.89 c. 10.48 d. 11.11 e. 2.89 ANS: D OBJ: Calculate pH given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids 113. Calculate the pH of 0.050 M Ba(CN)2 solution. Ba(CN)2 is a soluble ionic compound. a. 2.80 b. 2.96 c. 11.04 d. 11.20 e. 12.40 ANS: D OBJ: Calculate pH given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids 114. Calculate the percent hydrolysis of the hypochlorite ion in 0.10 M NaOCl solution. a. 0.0012% b. 0.024% c. 0.056% d. 0.10% e. 0.17% ANS: E OBJ: Calculate % hydrolysis given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids 115. What is the percent hydrolysis in 0.075 M sodium acetate, NaCH3COO, solution? a. 0.0087% b. 0.012% c. 0.0064% d. 0.0038% e. 0.043% ANS: A OBJ: Calculate % hydrolysis given basic salt concentration. TOP: Salts of Strong Bases and Weak Acids 116. Calculate the [OH] in 0.050 M potassium fluoride, KF. a. 4.7 107 M b. 6.2 107 M c. 8.3 107 M d. 1.4 106 M e. 2.2 106 M ANS: C OBJ: Calculate hydroxide ion concentration given molarity of a basic salt. TOP: Salts of Strong Bases and Weak Acids
Whitten 10e
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117. Calculate the [OH] in 0.20 M NaNO2. a. 4.8 109 M b. 1.4 108 M c. 1.2 107 M d. 6.5 107 M e. 2.1 106 M ANS: E OBJ: Calculate hydroxide ion concentration given molarity of a basic salt. TOP: Salts of Strong Bases and Weak Acids 118. What is the [OH] in 0.20 M sodium cyanate, NaOCN, solution? a. 3.7 107 M b. 4.6 107 M c. 5.5 107 M d. 2.4 106 M e. 8.7 107 M ANS: D OBJ: Calculate hydroxide ion concentration given molarity of a basic salt. TOP: Salts of Strong Bases and Weak Acids 119. What is the [H3O+] in 0.40 M NaCN solution? a. 6.4 1010 M b. 3.3 1011 M c. 1.4 102 M d. 4.8 103 M e. 3.2 1012 M ANS: E OBJ: Calculate hydronium ion concentration given molarity of a basic salt. TOP: Salts of Strong Bases and Weak Acids 120. Calculate the [H3O+] in 0.030 M potassium fluoride, KF. a. 2.5 108 M b. 1.5 108 M c. 8.3 109 M d. 6.8 104 M e. 5.5 109 M ANS: B OBJ: Calculate hydronium ion concentration given molarity of a basic salt. TOP: Salts of Strong Bases and Weak Acids 121. Calculate the [HCN] in a 0.20 M KCN solution. a. 8.9 106 M b. 1.1 109 M c. 4.5 1012 M d. 2.2 103 M e. 5.0 103 M
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ANS: D DIF: Harder Question OBJ: Calculate acid concentration given molarity of a basic salt. TOP: Salts of Strong Bases and Weak Acids 122. Which one of the following salts produces acidic solutions when it is dissolved in water? a. KCH3COO b. KF c. KOCl d. KBr e. NH4NO3 ANS: E OBJ: Identify the acidic salt. TOP: Salts of Weak Bases and Strong Acids 123. Which one of the following salts produces acidic aqueous solutions? a. sodium chloride b. sodium acetate c. ammonium chloride d. calcium nitrate e. rubidium perchlorate ANS: C OBJ: Identify the acidic salt. TOP: Salts of Weak Bases and Strong Acids 124. Which of the following acid / base pairs produce acidic salts when they react? a. HNO3 / NH3 b. HNO3 / (CH3)3N c. HCl / C6H5NH2 d. All of these choices. e. None of these choices. ANS: D OBJ: Identify the acid-base reactants which produce an acidic salt. TOP: Salts of Weak Bases and Strong Acids 125. Which one of the following salts does not produce an acidic aqueous solution? a. NH4Cl b. NH4NO3 c. NH4Br d. NH4I e. NaNO3 ANS: E OBJ: Identify the neutral salt. TOP: Salts of Weak Bases and Strong Acids 126. The reaction that occurs when NH4Br dissolves in water is ____. a. NH4+ + OH NH4OH b. Br + H3O+ HBr + H2O c. NH3 + H2O NH4+ + OH + d. NH4 + H2O NH3 + H3O+ e. Br + H2O HBr + OH Whitten 10e
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672
ANS: D OBJ: Identify the reaction that results from dissolution of an acidic salt. TOP: Salts of Weak Bases and Strong Acids 127. The value of Kb for methylamine, (CH3)NH2, is 5.0 104. When methylammonium chloride is dissolved in water, the reaction that occurs is ____, resulting in a solution that is ____. a. (CH3)NH2 + H2O (CH3)NH3+ + OH; basic + b. (CH3)NH3 + H2O (CH3)NH2 + H3O+; acidic c. (CH3)NH3+ + OH (CH3)NH2 + H2O; acidic d. (CH3)NH3+ + OH (CH3)NH2 + H2O; basic e. (CH3)NH2 + H3O+ (CH3)NH3+ + H2O; acidic ANS: B OBJ: Deduce the balanced reaction and solution acidity from the Kb and formula of a base. TOP: Salts of Weak Bases and Strong Acids 128. Consider solutions of the five indicated salts dissolved in water. Which one could not possibly have the pH designated?
a. b. c. d. e.
Salt Solution NaCl NaF NH4Cl KCN NH4NO3
pH 7.00 8.16 7.64 9.48 5.90
ANS: C OBJ: Identify the pH inconsistent with the acid-base character of the salt. TOP: Salts of Weak Bases and Strong Acids 129. Calculate the hydrolysis constant for the ammonium ion, NH4+. a. 2.5 105 b. 1.0 107 c. 4.0 1010 d. 5.6 1010 e. 5.5 104 ANS: D OBJ: Calculate the Ka of an acid. TOP: Salts of Weak Bases and Strong Acids 130. Calculate the pH of 0.030 M NH4Cl. a. 4.78 b. 4.90 c. 5.12 d. 5.28 e. 5.39 ANS: E OBJ: Calculate pH given an acidic salt concentration. TOP: Salts of Weak Bases and Strong Acids
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673
131. The value of Kb for methylamine, (CH3)2NH, is 7.4 104. What is the pH of a solution containing 0.32 M dimethyl ammonium ion, (CH3)2NH2+? a. 5.68 b. 6.58 c. 8.32 d. 5.43 e. 4.34 ANS: A OBJ: Calculate pH given Kb and the molarity of the conjugate acid. TOP: Salts of Weak Bases and Strong Acids 132. Calculate the pH of 0.050 M CH3NH3Br. a. 4.70 b. 4.15 c. 5.28 d. 5.35 e. 6.00 ANS: E OBJ: Calculate pH given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 133. Calculate the pH of 0.15 M NH4NO3 solution. a. 5.04 b. 5.20 c. 5.36 d. 8.80 e. 8.96 ANS: A OBJ: Calculate pH given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 134. Calculate the pH of 0.020 M (CH3)3NHBr. a. 4.93 b. 5.78 c. 11.57 d. 8.17 e. 4.09 ANS: B OBJ: Calculate pH given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 135. What is the pH of 0.15 M solution of trimethylammonium nitrate, (CH3)3NHNO3, a salt? a. 8.66 b. 9.20 c. 8.88 d. 5.12 e. 5.34 ANS: E OBJ: Calculate pH given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids Whitten 10e
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674
136. What is the [H3O+] in 0.060 M NH4Cl? a. 8.7 106 M b. 7.6 106 M c. 6.6 106 M d. 5.8 106 M e. 4.5 106 M ANS: D OBJ: Calculate hydronium ion concentration given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 137. Calculate the [H3O+] in a 0.10 M solution of NH4NO3. a. 1.7 105 M b. 7.5 106 M c. 2.2 106 M d. 5.8 107 M e. 1.3 109 M ANS: B OBJ: Calculate hydronium ion concentration given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 138. Calculate the [OH] in a 0.20 M NH4Cl solution. a. 1.3 109 M b. 9.5 1010 M c. 1.0 107 M d. 1.2 106 M e. 1.7 104 M ANS: B OBJ: Calculate hydroxide ion concentration given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 139. What is the percent hydrolysis of a 0.15 M solution of (CH3)3NHNO3? a. 0.0031% b. 0.0068% c. 0.0094% d. 0.011% e. 0.022% ANS: A OBJ: Calculate % hydrolysis given molarity of acidic salt. TOP: Salts of Weak Bases and Strong Acids 140. A 0.10 M solution of which of the following salts is neutral? a. NH4F b. NH4NO2 c. NH4CH3COO d. NH4OCl e. NH4CN ANS: C OBJ: Identify the neutral salt. TOP: Salts of Weak Bases and Weak Acids Whitten 10e
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141. Consider an aqueous solution of ammonium hypochlorite. This is a(n) ____ salt. The resulting solution is ____. a. insoluble; acidic b. soluble; acidic c. insoluble; basic d. soluble; basic e. soluble; neutral ANS: D OBJ: Classify a salt as soluble or insoluble and acidic, basic, or neutral. TOP: Salts of Weak Bases and Weak Acids 142. Which of the following salts are incorrectly matched with its description? a. NH4CH3COO / neutral b. NaOBr / basic c. NH4OCl / basic d. NH4NO3 / acidic e. NH4CN / acidic ANS: E OBJ: Identify the salt that is incorrectly classified as basic, acidic, or neutral. TOP: Salts of Weak Bases and Weak Acids 143. A 0.10 M solution of which of the following salts is most basic? a. NH4F b. NH4NO2 c. NH4CH3COO d. NH4OCl e. NH4CN ANS: E DIF: Harder Question OBJ: Identify the salt that produces the most basic solution. TOP: Salts of Weak Bases and Weak Acids 144. Aqueous solutions of one of the following is acidic. Which one? a. NH4NO2 b. NH4CH3COO c. NH4OCl d. NH4OBr e. NH4CN ANS: A DIF: Harder Question OBJ: Identify the salt that produces an acidic solution. TOP: Salts of Weak Bases and Weak Acids 145. A 0.10 M solution of which of the following salts is most acidic? a. NH4F b. NH4NO2 c. NH4CH3COO d. NH4OCl e. NH4CN
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676
ANS: A DIF: Harder Question OBJ: Identify the salt which produces the most acidic solution. TOP: Salts of Weak Bases and Weak Acids 146. Which response contains all the salts whose aqueous solutions are acidic, and no other salts? I. NH4NO3 II. NaCN III. KCl IV. NH4Br V. LiCl VI. CaCl2 VII. CH3NH3Cl VIII. KNO2 IX. NH4CH3COO a. b. c. d. e.
II, III, V, VI, and VIII I, IV, and VII II, VIII, and IX I, IV, VII, and IX II and VIII
ANS: B OBJ: Identify the salts that produce acidic solutions. TOP: Salts of Weak Bases and Weak Acids 147. If 1.0 mole of ammonium cyanide, NH4CN, was dissolved in 1.0 liter of water, the pH of the solution would be ____. For NH3: Kb = 1.8 105 For HCN: Ka = 4.0 1010 a. b. c. d. e.
greater than 7 impossible to predict equal to 7 less than 7 close to 1
ANS: A OBJ: Approximate the pH of a solution of a salt of an acidic anion and basic cation. TOP: Salts of Weak Bases and Weak Acids 148. If 1.0 mole of ammonium nitrite, NH4NO2, was dissolved in 1.0 liter of water, the pH of the solution would be ____. For NH3: Kb = 1.8 105 For HNO2: Ka = 4.5 104 a. b. c. d. e.
greater than 7 impossible to predict equal to 7 less than 7 close to 14
ANS: D OBJ: Approximate the pH of a solution of a salt of an acidic anion and basic cation. TOP: Salts of Weak Bases and Weak Acids
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677
149. Which of the following statements about the hydrolysis of AlCl3 and other metal cations is false? a. The Al3+ ions become hydrated in solution to give [Al(H2O)6]3+. b. The aluminum ion hydrolyzes to give a basic solution. c. The positive Al3+ attracts the negative ends of polar water molecules. d. The hydrated cation will be octahedral. e. Smaller, more highly charged cations hydrolyze to a greater extent than larger, less highly charged cations. ANS: B OBJ: Identify the incorrect description of metal ion hydrolysis. TOP: Salts That Contain Small, Highly Charged Cations 150. Which response includes all the following salts that give acidic aqueous solutions, and no other salts? I. AlCl3 II. Cr(NO3)3 III. FeCl3 IV. CaCl2 V. BiCl3 a. b. c. d. e.
I and II I, II, III, and IV IV I, II, III, and V II and IV
ANS: D OBJ: Identify the acidic salts. TOP: Salts That Contain Small, Highly Charged Cations 151. Which of the following salts produce acidic solutions? a. Al(NO3)3 b. Co(ClO3)2 c. KCl d. Both (a) and (b). e. All of these choices. ANS: D OBJ: Identify the acidic salts. TOP: Salts That Contain Small, Highly Charged Cations 152. What is the pH of a 0.30 M FeCl2 solution? The hydrated ferrous ion is [Fe(OH2)6]2+. For [Fe(OH2)6]2+, Ka = 3.0 1010 a. b. c. d. e.
5.02 4.41 3.76 3.22 2.86
ANS: A OBJ: Calculate pH given the molarity of an ionic compound of a metal and Ka. TOP: Salts That Contain Small, Highly Charged Cations
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678
153. Calculate the pH of a 0.10 M solution of BeCl2 in water. The hydrated beryllium ion is [Be(OH2)4]2+. For [Be(OH2)4]2+, Ka = 1.0 105 a. b. c. d. e.
5.50 3.00 1.57 3.74 1.89
ANS: B OBJ: Calculate pH given the molarity of an ionic compound of a metal and Ka. TOP: Salts That Contain Small, Highly Charged Cations 154. What is the pH of 0.025 M CuCl2? For [Cu(OH2)4]2+, Ka = 1.0 108 a. b. c. d. e.
6.70 9.20 7.30 3.60 4.80
ANS: E OBJ: Calculate pH given the molarity of an ionic compound of a metal and Ka. TOP: Salts That Contain Small, Highly Charged Cations 155. What is the pH of a 0.10 M CuCl2 solution? For [Cu(OH2)4]2+, Ka = 1.0 108 a. b. c. d. e.
4.40 4.49 4.58 4.63 4.68
ANS: B OBJ: Calculate pH given the molarity of an ionic compound of a metal and Ka. TOP: Salts That Contain Small, Highly Charged Cations 156. Calculate the pH of 0.15 M Co(NO3)2. For [Co(OH2)6]2+, Ka = 5.0 1010 a. b. c. d. e.
4.52 4.74 4.88 5.06 5.28
ANS: D OBJ: Calculate pH given the molarity of an ionic compound of a metal and Ka. TOP: Salts That Contain Small, Highly Charged Cations
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679
157. Calculate the pH of a 0.050 M Fe(NO3)3 solution. The hydrated Fe3+ ion is [Fe(OH2)6]3+. For [Fe(OH2)6]3+, Ka = 4.0 103 a. b. c. d. e.
1.76 1.85 1.90 2.02 2.26
ANS: B OBJ: Calculate pH given the molarity of an ionic compound of a metal and Ka. TOP: Salts That Contain Small, Highly Charged Cations 158. What is the percent hydrolysis of Fe2+ in a 0.30 M FeCl2 solution? a. 0.20% b. 5.2 104% c. 0.067% d. 0.044% e. 0.0032% ANS: E OBJ: Calculate the % hydrolysis given molarity of an ionic compound of a metal. TOP: Salts That Contain Small, Highly Charged Cations 159. At 40°C, the ion-product constant of water, Kw, is 2.88 1014 . What is the pH of pure water at 40°C? a. 7.000 b. 6.190 c. 6.870 d. 6.770 e. none of these ANS: D DIF: moderate OBJ: Determine the pH of water at varying temperatures given the equilibrium constant. TOP: The Autoionization of Water 160. What is the hydronium-ion concentration of a 0.0029 M KOH solution? a. 3.4 10–12 M b. 2.9 10–3 M c. 1.0 10–14 M d. 1.0 10–7 M e. 2.9 10–17 M ANS: A DIF: easy OBJ: Determine the hydronium concentration of a strong base. TOP: The pH and pOH Scales 161. What is the pH of the final solution when 25 mL of 0.021 M HCl has been added to 35 mL of 0.036 M HCl at 25°C? a. 3.3 b. 1.9 c. 1.5 d. 2.7 e. 3.5 Whitten 10e
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ANS: C DIF: moderate OBJ: Determine the pH of a mixture of a strong acids. TOP: The pH and pOH Scales 162. Consider the Ka values for the following acids: Cyanic acid, HOCN, 3.5 10–4 Formic acid, HCHO2, 1.7 10–4 Lactic acid, HC3H5O3, 1.3 10–4 Propionic acid, HC3H5O2, 1.3 10–5 Benzoic acid, HC7H5O2, 6.3 10–5 Which has the strongest conjugate base? a. b. c. d. e.
propionic acid benzoic acid lactic acid formic acid cyanic
ANS: A DIF: easy OBJ: Use the Ka's to determine the strongest or weakest acid or base. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 163. Consider the Ka values for the following acids: Cyanic acid, HOCN, 3.5 10–4 Formic acid, HCHO2, 1.7 10–4 Lactic acid, HC3H5O3, 1.3 10–4 Propionic acid, HC3H5O2, 1.3 10–5 Benzoic acid, HC7H5O2, 6.3 10–5 Given initially equimolar solutions of each weak acid, which solution will have the highest hydronium ion concentration once equilibrium is established? a. b. c. d. e.
cyanic acid benzoic acid lactic acid formic acid propionic acid
ANS: A DIF: easy OBJ: Use the Ka's to determine the strongest or weakest acid or base. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 164. What is the percent ionization of a 1.8 M HC2H3O2 solution (Ka = 1.8 10–5 ) at 25°C? a. 0.57 % b. 0.32 % c. 1.8 % d. 0.18 % e. 0.24 % Whitten 10e
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ANS: B DIF: easy OBJ: Determine the percent ionization given formal concentration and K. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 165. A 0.010 M aqueous solution of a weak acid HA has a pH of 5.0. What is the degree of ionization of HA in the solution? a. 1 % b. 0.01 % c. 10 % d. 0.1 % e. 0.001 % ANS: D DIF: moderate OBJ: Determine the percent ionization given formal concentration and equilibrium pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 166. A 0.0367 M solution of a weak base has a pH of 11.59. What is the identity of the weak base? Weak Base Ethylamine (CH3CH2NH2) Hydrazine (N2H4) Hydroxylamine (NH2OH) Pyridine (C5H5N) Aniline (C6H5NH2) a. b. c. d. e.
Kb 4.7 10–4 1.7 10–6 1.1 10–8 1.4 10–9 4.2 10–10
hydrazine pyridine aniline ethylamine
hydroxylamine
ANS: D DIF: moderate OBJ: Identify the weak base given the formal concentration and equilibrium pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 167. Consider the reaction NH3(aq) + H2O(l) What is Ka for the NH4+ ion at 25°C? a. 5.6 104 b. 5.6 10–10 c. 1.8 10–5 d. 7.2 10–12 e. 9.2 10–8
NH4+(aq) + OH–(aq). Kb for NH3 is 1.8 10–5 at 25°C.
ANS: B DIF: easy OBJ: Determine Ka given Kb. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
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168. What is the pH of a 0.38 M solution of sodium propionate, NaC3H5O2, at 25°C? (For propionic acid, HC3H5O2, Ka = 1.3 10–5 at 25°C.) a. 6.11 b. 4.77 c. 11.10 d. 7.89 e. 9.23 ANS: E DIF: easy OBJ: Calculate the pH of a solution of weak base given Ka and the formal concentration. TOP: Salts of Weak Bases and Weak Acids 169. The hydronium ion concentration in an aqueous solution at 25oC is 6.1 x 10-2M. What is the
hydroxide ion concentration in this solution? a. 6.1 x 10-2 b. 1.6 x 10-13 c. 6.1 x 10-16 d. 1.3 x 10-6 e. 7.8 x 10-16 ANS: B 170. The hydronium ion concentration in an aqueous solution at 25oC is 6.1 x 10-2M. What is the
pH of this solution? a. 1.21 b. 12.79
c. 8.21
d. 7.90
e. 11.20
ANS: A OBJ: Calculate pH given the hydronium ion concentration. TOP: The pH and pOH Scales 171. The value of Ka for phenol, C6H5OH, is 1.00 x 10-10. Which of the equations below illustrates
this reaction for phenol? a. C6H5OH(aq) + H2O(l) b. C6H5OH(aq) + H2O(l) c. C6H5OH(aq) + OH-(l) d. C6H5OH(aq) + H3O+(aq) e. C6H5O-(aq) + H3O+(aq)
C6H5OH2+(aq) + OH-(aq) C6H5O-(aq) + H3O+(aq) C6H5O-(aq) + H2O(l) C6H5OH2+(aq) + H2O(l) C6H5OH(aq) + H2O(l)
ANS: B OBJ: Identify the correct equilibrium for a weak acid. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
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172. Which of the following is the correct equilibrium expression for an aqueous solution of
hydrocyanic acid, HCN: a.
Ka = b.
Ka =
c. Ka = [H+][CN-] d.
Ka =
e. Ka = [H+][CN-][HCN] ANS: A OBJ: Identify the correct weak acid equilibrium expression. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 173. Given the following acids and their Ka values:
Phenol, C6H5OH Ka = 1.00 x 10-10 Acetic acid, CH3COOH Ka = 1.80 x 10-5 Nitrous acid, HNO2 Ka = 4.50 x 10-4 What is the order of increasing base strength for C6H5O-, CH3COO-, and NO2-? a. C6H5O- < NO2- < CH3COOb. NO2- < CH3COO- < C6H5Oc. CH3COO- < C6H5O- < NO2d. C6H5O- < CH3COO- < NO2e. CH3COO- < NO2- < C6H5OANS: B OBJ: Rank the conjugate base basicity given the acid Ka's. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
174. Given the following acids and their Ka values:
Hydrocyanic acid, HCN Ka = 4.00 x 10-10 Phenol, C6H5OH Ka = 1.00 x 10-10 Benzoic acid, C6H5COOH Ka = 6.30 x 10-5 What is the order of increasing base strength for CN-, C6H5O-, and C6H5COO-? a. C6H5COO- < C6H5O- < CNb. C6H5O- < C6H5COO- < CNc. CN- < C6H5COO- < C6H5Od. C6H5COO- < CN- < C6H5Oe. CN- < C6H5O- < C6H5COOANS: D OBJ: Rank the conjugate base basicity given the acid Ka's. TOP: Ionization Constants for Weak Monoprotic Acids and Bases
175. When 14.7 mL of aqueous HBr (strong acid) was added to water, 482 mL of a solution with a
pH of 4.23 was produced. What was the molarity of the original HBr solution? a. 140 M b. 1.7 M c. 0.29 M d. 0.13 M e. 0.0019 M
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ANS: E OBJ: Calculate the strong acid concentration given the pH. TOP: The pH and pOH Scales 176. A student measured the pH of a 0.15 M solution of chloroacetic acid (ClCH2COOH) to be
1.86. What is the value of Ka for this acid? a. 0.72 b. 0.16 c. 0.099
d. 0.0014
e. 0.00027
ANS: D OBJ: Calculate the Ka given the weak acid pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 177. Ka for formic acid (HCOOH) is 1.8 x 10-4. What is Kb for the formate ion (HCOO-)? a. 1.8 x 10-4 b. 6.9 x 10-6 c. 5.6 x 10-11 d. 4.1 x 10-9 e. 7.9 x 10-6 ANS: C OBJ: Calculate Kb given the Ka. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 178. What is the pH of a solution which has a hydroxide ion concentration of 2.5 x 10-2M? a. 1.24 b. 1.60 c. 3.69 d. 10.31 e. 12.40 ANS: E OBJ: Calculate the pH given the hydroxide ion concentration. TOP: The pH and pOH Scales 179. What is the hydronium ion (H3O+) concentration of an aqueous HCl solution that has a pOH
of 9.040? a. 7.01 x 10-3 b. 1.10 x 10-5 c. 4.96 x 10-8 d. 3.98 x 10-10 e. 9.12 x 10-10 ANS: B OBJ: Calculate the hydrogen ion concentration given the pOH. TOP: The pH and pOH Scales 180. In the laboratory, a general chemistry student measured the pH of a 0.583M solution of HClO3
to be 3.862. What is the experimentally determined value of Ka for HClO3? a. 1.37 x 10-4 b. 2.35 x 10-4 c. 3.11 x 10-7 d. 1.89 x 10-8 e. 3.24 x 10-8 ANS: E OBJ: Calculate Ka given the solution molarity and pH. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 181. The percent ionization of a 0.331M solution of HCN is found to be 0.00337%. What is
the pH of this solution? a. 1.992 b. 2.953 Whitten 10e
c. 3.371
d. 3.992
Test Bank
e. 4.953 685
ANS: E OBJ: Calculate the solution pH given the percent ionization and concentration. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 182. What is the equilibrium constant for the following reaction:
HCO2- + H2O HCO2H + OHThe Ka value for HCO2H is 1.8 x 10-4 a. 1.8 x 10-4 b. 4.7 x 10-6 c. 9.2 x 10-8
d. 5.6 x 10-11
e. 6.4 x 10-11
ANS: D OBJ: Calculate Kb given the Ka. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 183. What is the pH of an aqueous solution of 0.184M carbonic acid, H2CO3?
(Ka1 = 4.2 x 10-7, Ka2 = 4.8 x 10-11) a. 2.69 b. 2.80 c. 2.97
d. 3.50
e. 3.56
ANS: E OBJ: Calculate the pH given the molarity and equilibrium constants. TOP: Polyprotic Acids 184. Calculate the pH of a 0.308 M ascorbic acid solution, H2C6H6O6 (aq).
Ka1 = 7.9 x 10-5 and Ka2 = 1.6 x 10-12 a. 0.511 b. 1.781 c. 2.307
d. 3.425
e. 4.614
ANS: C OBJ: Calculate pH given the Ka and acid concentration. TOP: Polyprotic Acids 185. For the following reaction, K > 1.
C8H10N4O2(aq) + HF(aq) F-(aq) + HC8H10N4O2+(aq) Which is the strongest Brønsted-Lowry acid? a. C8H10N4O2 c. Fb. HF d. HC8H10N4O2+ ANS: B OBJ: Predict the strongest acid in a given equilibrium, given K. TOP: Ionization Constants for Weak Monoprotic Acids and Bases 186. What is the pH of a 1.0L solution of 0.445 M hydrocyanic acid, HCN? (Ka = 4.0 x 10-10) a. 3.516 b. 4.250 c. 4.602 d. 4.699 e. 4.875 ANS: E OBJ: Calculate the pH of a weak acid solution. TOP: Ionization Constants for Weak Monoprotic Acids and Bases CONCEPTUAL 1. Why are some acids stronger than others? Consider the conjugate bases of the strong acids, and compare these anions to your solubility rules. What can you conclude? OBJ: Explain the factors that influence acidity. TOP: Acids and Bases Whitten 10e
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2. Does adding table salt to your food change the pH of the food? Why or why not? OBJ: Explain why table salt is classified as a neutral salt. TOP: Salts of Strong Bases and Strong Acids 3. Soap is made from adding base to fats or oils, creating a sodium salt of an organic acid. If NaA represents the soap molecule, determine whether a soap solution burns your eyes because the NaA solution is acidic or basic. OBJ: Classify the salt of an organic acid as neutral, acidic, or basic. TOP: Salts of Weak Bases and Weak Acids 4. Why can we generally ignore the contribution of water to the hydronium ion concentration in a solution containing a weak acid? OBJ: Explain why acid from water autoionization can be ignored in many circumstances. TOP: The Autoionization of Water 5. Dimethylamine is a stronger base than trimethylamine when dissolved in solution. Which solution would be a better solvent to dissolve a very weak acid? OBJ: Explain which base would make a better solvent for a weak acid. TOP: Solvolysis 6. Calculate the % autoionization of pure water at room temperature. If the current human population of the earth (~5 billion) were water molecules, how many would be dissociated at any given time? OBJ: Calculate the percent ionization of water and number out of 5 billion molecules that are ionized at any given time. TOP: The Autoionization of Water
Chapter 19—Ionic Equilibria II: Buffers and Titration Curves MULTIPLE CHOICE Chapter 19 Values The following equilibrium constants will be useful for the problems in this chapter. Substance HCO2H HNO2 HOCl HF HCN H2SO4 HOBr
Constant Ka = 1.8 104 Ka = 4.5 104 Ka = 3.5 108 Ka = 7.2 104 Ka = 4.0 1010 K1 = very large K2 = 1.2 102 Ka = 2.5 109
Substance H2CO3 (COOH)2 CH3COOH HOCN C6H5NH2 NH3
Constant K1 = 4.2 107 K2 = 4.8 1011 K1 = 5.9 102 K2 = 6.4 105 Ka = 1.8 105 Ka = 3.5 104 Kb = 4.2 1010 Kb = 1.8 105
1. A(n) ____ solution contains a conjugate acid-base pair with both the acid and the base in reasonable concentrations. a. saturated b. electrolytic Whitten 10e
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c. buffer d. titrated e. equivalence ANS: C OBJ: Identify a description of a buffer. TOP: The Common Ion Effect and Buffer Solutions 2. When a solution of weak electrolyte is altered by adding one of its ions from another source, the ionization of the weak electrolyte is suppressed. This behavior is termed the ____. a. common ion effect b. buffer effect c. titration curve d. equivalence point e. partial neutralization effect ANS: A OBJ: Identify a description of the common ion effect. TOP: The Common Ion Effect and Buffer Solutions 3. The pH of a 0.03 M formic acid (HCOOH) solution is 2.63. If 0.03 M sodium formate (NaHCOO) is added, which of the following statements is true? a. The pH decreases. b. The equilibrium position is shifted to the left. c. The [H3O+] increases. d. The [HCOOH] decreases. e. None of these are true. ANS: B OBJ: Identify a consequence of the common ion effect. TOP: The Common Ion Effect and Buffer Solutions
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4. What is the [H3O+] of a solution that is 0.0100 M in HOCl and 0.0300 M in NaOCl? a. 2.14 107 M b. 1.45 107 M c. 7.41 108 M d. 2.29 108 M e. 1.17 108 M ANS: E OBJ: Calculate the hydronium ion concentration of a buffer. TOP: The Common Ion Effect and Buffer Solutions 5. Calculate the [H3O+] of a solution that is 0.20 M in HF and 0.10 M in NaF. a. 3.2 104 M b. 4.0 106 M c. 1.4 103 M d. 6.3 105 M e. 5.0 103 M ANS: C OBJ: Calculate the hydronium ion concentration of a buffer. TOP: The Common Ion Effect and Buffer Solutions 6. Calculate the pH of a solution that is 0.20 M in sodium hypobromite and 0.10 M in hypobromous acid. a. 4.15 b. 4.45 c. 8.60 d. 8.90 e. 8.30 ANS: D OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions 7. Calculate the pH of a solution that is 0.15 M in HOCl and 0.25 M in NaOCl. a. 7.23 b. 8.28 c. 8.06 d. 7.68 e. 9.10 ANS: D OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions 8. What is the pH of a solution which is 0.0400 M in formic acid, HCO2H, and 0.0600 M in sodium formate, NaHCOO? a. 3.92 b. 3.96 c. 4.00 d. 9.52 e. 4.08 ANS: A OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions Whitten 10e
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9. What is the pH of a solution that is 0.20 M in HCN and 0.15 M in KCN? a. 7.60 b. 8.40 c. 8.80 d. 9.27 e. 10.10 ANS: D OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions 10. What is the pH of a 0.22 M HOCN solution containing 0.44 M NaOCN? a. 3.10 b. 3.16 c. 3.46 d. 2.80 e. 3.77 ANS: E OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions 11. Calculate the pH of 500. mL of 0.100 M acetic acid, CH3COOH, which also contains 0.100 mole of sodium acetate, NaCH3COO. a. 4.77 b. 5.05 c. 5.32 d. 5.68 e. 7.00 ANS: B OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: The Common Ion Effect and Buffer Solutions 12. A solution is made by combining 500 mL of 0.10 M HF with 300 mL of 0.15 M NaF. What is the pH of the solution? a. 2.97 b. 3.10 c. 3.19 d. 3.22 e. 3.32 ANS: B DIF: Harder Question OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: The Common Ion Effect and Buffer Solutions 13. Calculate the pH of a solution that is 0.050 M in HCN and 0.025 M in Ba(CN)2. a. 7.60 b. 8.80 c. 9.10 d. 10.20 e. 9.40
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ANS: E DIF: Harder Question OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: The Common Ion Effect and Buffer Solutions 14. Calculate the pH of a solution which is 0.400 M in HNO2 and 1.875 M in Ca(NO2)2. a. 3.64 b. 4.06 c. 4.87 d. 5.68 e. 4.32 ANS: E DIF: Harder Question OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: The Common Ion Effect and Buffer Solutions 15. What is the pH of an aqueous solution containing CH3COOH and NaCH3COO in a molar ratio of 4.0 to 1.0? a. 4.37 b. 4.14 c. 9.25 d. 5.35 e. 4.74 ANS: B OBJ: Calculate the pH of a buffer given the molar ratio of acid and conjugate base. TOP: The Common Ion Effect and Buffer Solutions 16. A solution that is 0.20 M in NH3 is also 0.30 M in NH4Cl. What is the [OH] in this solution? a. 4.5 106 M b. 1.2 105 M c. 7.4 105 M d. 6.4 104 M e. 2.4 107 M ANS: B OBJ: Calculate the hydroxide ion concentration of a buffer. TOP: The Common Ion Effect and Buffer Solutions 17. What is the [H3O+] of a solution that is 0.010 M in aqueous NH3 and 0.030 M in NH4NO3? a. 7.2 106 M b. 6.0 106 M c. 1.7 109 M d. 1.4 109 M e. 1.2 109 M ANS: C OBJ: Calculate the hydronium ion concentration of a buffer. TOP: The Common Ion Effect and Buffer Solutions
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18. What is the pH of a solution that is 0.080 M in aqueous ammonia and 0.040 M in NH4Cl? a. 2.92 b. 4.44 c. 7.00 d. 9.56 e. 11.08 ANS: D OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions 19. What is the pH of a solution that is 0.30 M in aniline, C6H5NH2, and 0.15 M in anilinium chloride, C6H5NH3+Cl? Aniline ionizes as follows. C6H5NH2 + H2O C6H5NH3+ + OH a. b. c. d. e.
4.32 4.92 5.62 5.74 5.95
ANS: B OBJ: Calculate the pH of a buffer. TOP: The Common Ion Effect and Buffer Solutions 20. What is the pH of a solution containing aqueous ammonia and ammonium nitrate in a molar ratio of 5.0 to 3.0? a. 4.52 b. 4.96 c. 9.04 d. 9.26 e. 9.48 ANS: E OBJ: Calculate the pH of a buffer given the molar ratio of acid and conjugate base. TOP: The Common Ion Effect and Buffer Solutions 21. Which one of the following combinations cannot produce a buffer solution? a. HNO2 and NaNO2 b. HCN and NaCN c. HClO4 and NaClO4 d. NH3 and (NH4)2SO4 e. NH3 and NH4Br ANS: C OBJ: Identify the pair of compounds that do not form a buffer. TOP: Buffering Action 22. Which one of the following combinations is not a buffer solution? a. NH3 / (NH4)2SO4 b. HBr / KBr c. HCN / NaCN d. NH3 / NH4Br e. CH3COOH / NaCH3COO
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ANS: B OBJ: Identify the pair of compounds that do not form a buffer. TOP: Buffering Action 23. Which of the following statements about buffers is false? a. A buffer resists changes in pH. b. A buffer always consists of a weak acid and a soluble ionic salt of the weak acid. c. A buffer solution can react with either H3O+ or OH ions. d. Most body fluids contain natural buffer systems. e. Many medications are buffered to prevent digestive upset. ANS: B OBJ: Identify the incorrect description of a buffer. TOP: Buffering Action 24. A buffer is prepared using 0.085 M formic acid and 0.085 M sodium formate. Which of the following statements is false? a. The addition of 0.02 M HCl will decrease the pH slightly. b. The addition of 0.02 M NaOH will increase the pH slightly. c. The formate ion can neutralize bases added to the buffer. d. The addition of 1.0 M HCl will cause the pH to drop significantly. e. Diluting the solution with pure water won't change the pH of the buffer. ANS: C OBJ: Identify the incorrect description of a buffer. TOP: Buffering Action 25. Choose the response that includes all the following combinations that are buffer solutions and none that are not buffer solutions. All components are present in 0.10 M concentrations. I. HCN and NaCN II. NH3 and NH4Cl III. HNO3 and NH4NO3 IV. H2SO4 and Na2SO4 a. b. c. d. e.
I, III, and IV I and II II, III, and IV III and IV I and III
ANS: B OBJ: Identify the compound pairs that form buffers. TOP: Buffering Action 26. A solution is initially 0.100 M in HOCl and 0.300 M in NaOCl. What is the pH if 0.030 mol of solid NaOH is added to 1.00 L of this solution? Assume no volume change. a. 5.24 b. 5.38 c. 8.02 d. 8.13 e. 9.06 ANS: D OBJ: Calculate the pH of a buffer after the addition of a strong base. TOP: Buffering Action Whitten 10e
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27. What is the pH of a solution that is 0.15 M in HOCl and 0.25 M NaOCl after 0.050 mol HCl/L has been bubbled into the solution? a. 7.46 b. 6.15 c. 6.98 d. 7.23 e. 7.93 ANS: A OBJ: Calculate the pH of a buffer after the addition of a strong acid. TOP: Buffering Action 28. If 100. mL of 0.040 M NaOH solution is added to 100. mL of solution which is 0.10 M in CH3COOH and 0.10 M in NaCH3COO, what be will the pH of the new solution? a. 4.74 b. 4.81 c. 4.89 d. 5.00 e. 5.11 ANS: E OBJ: Calculate the pH of a buffer after the addition of a strong base. TOP: Buffering Action 29. If 0.040 moles of solid NaOH is added to 1.0 liter of a solution that is 0.10 M in NH3 and 0.20 M in NH4Cl, what will be the pH of the resulting solution? Assume no volume change due to the addition of the NaOH. a. 4.80 b. 8.95 c. 5.05 d. 8.65 e. 9.20 ANS: E OBJ: Calculate the pH of a buffer after the addition of a strong base. TOP: Buffering Action 30. If 0.050 moles of gaseous HCl is bubbled in 1.0 liter of a solution that is 0.15 M in NH3 and 0.10 M in NH4Cl, what will be the pH of the resulting solution? a. 7.05 b. 9.08 c. 4.57 d. 9.43 e. 4.92 ANS: B OBJ: Calculate the pH of a buffer after the addition of a strong acid. TOP: Buffering Action
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31. If 100. mL of 0.030 M HCl solution is added to 100. mL of buffer solution which is 0.10 M in NH3 and 0.10 M in NH4Cl, what will be the pH of the new solution? a. 5.01 b. 4.48 c. 7.88 d. 8.99 e. 9.52 ANS: D OBJ: Calculate the pH of a buffer after the addition of a strong acid. TOP: Buffering Action 32. If 0.40 g of solid NaOH is added to 1.0 liter of a buffer solution that is 0.10 M in CH3COOH and 0.10 M in NaCH3COO, how will the pH of the solution change? a. The pH increases from 4.74 to 4.83. b. The pH decreases from 7.00 to 4.83. c. The pH does not change. d. The pH decreases from 4.74 to 4.65. e. The pH increases from 4.74 to 7.00. ANS: A OBJ: Calculate the initial pH of a buffer and the pH after addition of a strong base. TOP: Buffering Action 33. Consider a buffer consisting of 0.75 M NH3 and 0.50 M NH4Cl. If 0.10 M H2SO4 is added to the solution with no change in volume, what is the resulting pH? a. 4.56 b. 9.44 c. 9.29 d. 9.16 e. 4.84 ANS: D OBJ: Calculate the pH of a buffer after the addition of a strong acid. TOP: Buffering Action 34. Calculate the pH for a buffer solution prepared by mixing 100. mL of 0.10 M HF and 200. mL of 0.10 M KF. a. 2.82 b. 2.96 c. 3.32 d. 3.44 e. 3.53 ANS: D OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: Preparation of Buffer Solutions 35. If 400. mL of 0.100 M CH3COOH and 200. mL of 0.100 M NaCH3COO solutions are mixed, what is the pH of the resulting solution? a. 3.09 b. 3.33 c. 3.78 d. 4.44 e. 4.60 Whitten 10e
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ANS: D OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: Preparation of Buffer Solutions 36. A buffer solution is prepared by mixing 250. mL of 1.00 M CH3COOH with 500. mL of 0.500 M calcium acetate, Ca(CH3COO)2. Calculate the pH. a. 5.36 b. 5.05 c. 4.74 d. 4.58 e. 4.40 ANS: B OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: Preparation of Buffer Solutions 37. A buffer solution is prepared by mixing 250. mL of 1.00 M HNO2 with 500. mL of 0.500 M calcium nitrite, Ca(NO2)2. Calculate the pH. a. 4.43 b. 3.35 c. 3.05 d. 3.65 e. 4.88 ANS: D OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: Preparation of Buffer Solutions 38. It is desired to buffer a solution at pH = 4.30. What molar ratio of CH3COOH to NaCH3COO should be used? a. 1.2/1 b. 0.8/1 c. 0.12/1 d. 2.8/1 e. 6.2/1 ANS: D DIF: Harder Question OBJ: Calculate the acid-conjugate base molar ratio of a buffer. TOP: Preparation of Buffer Solutions 39. Calculate the ratio [CH3COOH]/[NaCH3COO] that gives a solution with pH = 5.00. [CH3COOH]/[NaCH3COO] ____. a. b. c. d. e.
0.28 0.36 0.44 0.56 0.63
ANS: D DIF: Harder Question OBJ: Calculate the acid-conjugate base molar ratio of a buffer. TOP: Preparation of Buffer Solutions
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40. What ratio of NaOCN/HOCN will produce a buffer with pH = 3.10? a. 0.50 b. 1.1 c. 0.44 d. 2.3 e. 1.4 ANS: C OBJ: Calculate the acid-conjugate base molar ratio of a buffer. TOP: Preparation of Buffer Solutions 41. What ratio of NH4Cl/NH3 should be used to give a buffer with pH = 8.50? a. 5.7 b. 0.17 c. 0.76 d. 1.3 e. 4.2 ANS: A OBJ: Calculate the acid-conjugate base molar ratio of a buffer. TOP: Preparation of Buffer Solutions 42. Calculate the mass of solid NaCH3COO that must be added to 1.0 liter of 0.20 M CH3COOH solution so that the pH of the resulting solution will be 5.00. Assume no volume change due to addition of solid NaCH3COO. a. 15 g b. 20 g c. 25 g d. 30 g e. 35 g ANS: D OBJ: Calculate the mass of conjugate base to be mixed with a known quantity of acid to achieve a certain pH. TOP: Preparation of Buffer Solutions 43. How many grams of KNO2 must be added to 5.00 liters of 0.67 M HNO2 solution to produce a buffer with pH = 3.15? Assume no change in volume. a. 181 g b. 3.15 g c. 270 g d. 53.6 g e. 315 g ANS: A OBJ: Calculate the mass of conjugate base to be mixed with a known quantity of acid to achieve a certain pH. TOP: Preparation of Buffer Solutions
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44. If 0.090 mole of solid NaOH is added to 1.0 liter of 0.180 M CH3COOH, what will be the pH of the resulting solution? Assume no volume change due to addition of NaOH. a. 4.51 b. 4.74 c. 5.08 d. 5.70 e. 5.94 ANS: B OBJ: Calculate the pH of a buffer made by mixing a strong base with a weak acid. TOP: Preparation of Buffer Solutions 45. One of the following buffer solutions has pOH = 5.05. Which one? Hint: Solve the general problem rather than 5 specific problems. a. 0.10 M NH3 and 0.10 M NH4Cl b. 0.10 M NH3 and 0.20 M NH4Cl c. 0.20 M NH3 and 0.10 M NH4Cl d. 0.050 M NH3 and 0.20 M NH4Cl e. 0.20 M NH3 and 0.050 M NH4Cl ANS: B OBJ: Identify the buffer with the given pH. TOP: Preparation of Buffer Solutions 46. Calculate the pH for a buffer solution prepared by mixing 100. mL of 0.60 M NH3 and 200. mL of 0.45 M NH4Cl. a. 8.65 b. 9.08 c. 9.87 d. 4.90 e. 6.62 ANS: B OBJ: Calculate the pH of a buffer after determining the acid and conjugate base concentrations. TOP: Preparation of Buffer Solutions 47. Calculate the ratio [NH3]/[NH4Cl] that gives a solution with pH = 9.48. a. 0.33 b. 3.0 c. 1.7 d. 0.61 e. 4.5 ANS: C DIF: Harder Question OBJ: Calculate the acid-conjugate base molar ratio of a buffer. TOP: Preparation of Buffer Solutions 48. How many moles of NH4Cl must be added to 1.00 liter of 0.010 M aqueous NH3 to adjust the pH to 10.00? a. 3.6 105 mol b. 3.6 103 mol c. 2.7 103 mol d. 1.8 103 mol e. 1.8 102 mol Whitten 10e
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ANS: D OBJ: Calculate the moles of acid to be mixed with a known quantity of conjugate base to achieve a certain pH. TOP: Preparation of Buffer Solutions 49. How much NH4Cl must be added to 2.00 liters of 0.200 M aqueous ammonia to give a solution with pH = 8.20? Assume no volume change due to the addition of NH4Cl. a. 246 g b. 166 g c. 2.25 g d. 123 g e. 14.6 g ANS: A OBJ: Calculate the moles of acid to be mixed with a known quantity of conjugate base to achieve a certain pH. TOP: Preparation of Buffer Solutions 50. If 0.10 mole of HCl is bubbled into 1.0 liter of 0.25 M NH3 solution, what will be the pH of the resulting solution? a. 9.08 b. 4.56 c. 9.68 d. 4.92 e. 9.44 ANS: E OBJ: Calculate the pH of a buffer made by mixing a strong acid with a weak base. TOP: Preparation of Buffer Solutions 51. Which response is false? An acid-base indicator ____. a. might be an acid b. might have only one highly colored form c. might be a base d. might have two highly colored forms e. can be non-polar ANS: E OBJ: Identify the incorrect description of an acid-base indicator. TOP: Acid-Base Indicators 52. Which of the following statements about indicators is false? a. An indicator is an organic dye. b. An indicator's color depends on the [H3O+]. c. Phenolphthalein is colorless when the pH > 8. d. Many acid-base indicators are weak acids. e. Some indicators are vegetable/plant dyes. ANS: C OBJ: Identify the incorrect description of an acid-base indicator. TOP: Acid-Base Indicators
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53. The nonionized form of an acid indicator is yellow, and its anion is blue. The Ka of this indicator is 106. What will be the approximate pH range over which this indicator changes color? a. 35 b. 46 c. 57 d. 810 e. 911 ANS: C OBJ: Approximate the pH range over which an indicator changes color. TOP: Acid-Base Indicators 54. The nonionized form of an acid indicator is yellow, and its anion is blue. The Ka of this indicator is 105. What will be the color of the indicator in a solution of pH 5? a. red b. orange c. yellow d. green e. blue ANS: D OBJ: Approximate the pH range over which an indicator changes color. TOP: Acid-Base Indicators 55. The equivalence point of the titration of an unknown base with HCl is at pH = 5.90. What would be the Ka for the best choice of an indicator for this titration? a. 102 b. 104 c. 108 d. 106 e. 107 ANS: D OBJ: Identify the best indicator Ka for a given equivalence point pH. TOP: Acid-Base Indicators 56. The equivalence point of the titration of an unknown acid with NaOH is at pH = 8.10. What would be the Ka for the best choice of an indicator for this titration? a. 102 b. 104 c. 108 d. 106 e. 107 ANS: C OBJ: Identify the best indicator Ka for a given equivalence point pH. TOP: Acid-Base Indicators 57. Consider an indicator (KHIn = 6.3 106) that ionizes as shown below. Which of the following statements is false? HIn + H2O H3O+ + In yellow blue
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a. The ionized form of the indicator results in a blue solution. b. In acidic solutions containing the indicator, we would expect predominantly yellow color. c. Adding a base to a solution containing this indicator will cause the color to become yellow. d. At pH = 10.0, a solution of this indicator will be blue. e. At pH = 3.0, most of the indicator is in the non-ionized form. ANS: C OBJ: Identify the incorrect description of an acid-base indicator. TOP: Acid-Base Indicators 58. Which of the following statements about titration curves is false? a. A titration curve for titrating a strong acid/strong base will always have an equivalence point at pH = 7.0. b. A titration curve shows how pH changes near the equivalence point. c. The end point on a titration curve is the point where chemically equivalence amounts of acid and base have reacted. d. In titration curves for weak acid/weak base, pH changes near the equivalence point are too small for color changes to be used. e. The equivalence point will be basic when titrating a weak acid with a strong base. ANS: C OBJ: Identify an incorrect description of a titration curve. TOP: Strong Acid/Strong Base Titration Curves 59. Which is the best indicator for the titration of HCl solution with NaOH solution, i.e. the most nearly ideal one?
a. b. c. d. e.
Acid Range Color pH Range pink 1.22.8 blue 3.44.6 yellow 6.57.8 colorless 9.911.1 none of these indicators
Basic Range Color yellow yellow purple red
ANS: C OBJ: Identify the best indicator for a strong acid-strong base titration. TOP: Strong Acid/Strong Base Titration Curves 60. Consider the titration curve describing the titration of a strong acid by addition of a strong base. Which of the following statements is false? a. The equivalence point is at pH = 7.0. b. The pH is lower at the end of the titration than at the beginning. c. The pH increases rapidly around the equivalence point. d. At the equivalence point, the only species present are water and a neutral salt. e. The pH does not increase very rapidly at the beginning of the titration. ANS: B OBJ: Identify an incorrect description of a strong acid-strong base titration. TOP: Strong Acid/Strong Base Titration Curves 61. Which of the following acid / base pairs used in a titration would produce an equivalence point at pH = 7.0? Whitten 10e
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a. b. c. d. e.
HI / NH3 HI / RbOH HNO2 / NH3 HClO3 / NH3 HCN / NaOH
ANS: B OBJ: Identify the strong acid-strong base pair. TOP: Strong Acid/Strong Base Titration Curves 62. What is the pH at the point in a titration at which 20.00 mL of 1.000 M KOH has been added to 25.00 mL of 1.000 M HBr? a. 1.67 b. 0.95 c. 3.84 d. 2.71 e. 1.22 ANS: B OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 63. Calculate the pH of a solution prepared by adding 80.0 mL of 0.100 M NaOH solution to 100. mL of 0.100 M HNO3 solution. a. 1.95 b. 2.02 c. 2.08 d. 2.16 e. 2.24 ANS: A OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 64. Calculate the pH of a solution prepared by adding 115 mL of 0.100 M NaOH to 100. mL of 0.100 M HNO3 solution. a. 11.60 b. 11.68 c. 11.76 d. 11.84 e. 11.92 ANS: D OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 65. If 50.00 mL of 0.1000 M NaOH is titrated with 0.1000 M HCl, what is the pH of the solution after 30.00 mL of HCl solution has been added? a. 13.00 b. 12.40 c. 12.60 d. 12.00 e. 12.80
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ANS: B OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 66. Calculate the pH of the solution resulting from the addition of 30.0 mL of 0.200 M HClO4 to 60.0 mL of 0.150 M NaOH. a. 1.47 b. 7.00 c. 11.88 d. 12.52 e. 13.06 ANS: D OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 67. Calculate the pH of the solution resulting from the addition of 100.0 mL of 0.20 M HClO4 to 100.0 mL of 0.15 M NaOH. a. 1.3 b. 1.6 c. 7.0 d. 12.4 e. 12.7 ANS: B OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 68. What is the pH of the solution resulting from the addition of 30.0 mL of 0.200 M HClO4 to 20.0 mL of 0.150 M NaOH? a. 1.00 b. 1.22 c. 1.36 d. 1.48 e. 1.67 ANS: B OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves 69. What is the pH of the solution resulting from the addition of 40.0 mL of 0.200 M HClO4 to 20.0 mL of 0.150 M NaOH? a. 1.08 b. 1.25 c. 1.36 d. 1.48 e. 1.67 ANS: A OBJ: Calculate the pH of a mixture of strong acid and strong base. TOP: Strong Acid/Strong Base Titration Curves
Whitten 10e
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70. Which titration curve could describe the titration of a solution of HCl by addition of a solution of KOH? a.
b.
c.
d.
e.
ANS: B OBJ: Identify the titration curve of a strong base added to a strong acid. TOP: Strong Acid/Strong Base Titration Curves
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71. Which titration curve could describe the titration of a solution of NaOH by addition of a solution of HCl? a.
b.
c.
d.
e.
ANS: C OBJ: Identify the titration curve of a strong acid added to a strong base. TOP: Strong Acid/Strong Base Titration Curves 72. When a weak acid is titrated with a strong base, the pH at the equivalence point is always ____. a. 7 b. < 7 c. > 7 d. < 1 e. > 4 ANS: C OBJ: Estimate the equivalence point pH of a weak acid-strong base titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
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73. When a weak base is titrated with a strong acid, the pH at the equivalence point is always ____. a. 7 b. < 7 c. > 7 d. < 1 e. > 4 ANS: B OBJ: Estimate the equivalence point pH of a weak base-strong acid titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 74. Which indicator could be used to titrate CH3COOH with NaOH solution? a. b. c. d. e.
Acid Range Color pH Range pink 1.22.8 blue 3.44.6 yellow 6.57.8 colorless 8.39.9 none of these indicators
Basic Range Color yellow yellow purple red
ANS: D OBJ: Identify the best indicator for a weak acid-strong base titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 75. Which indicator could be used to titrate aqueous NH3 with HCl solution? a. b. c. d. e.
Acid Range Color pH Range pink 1.22.8 blue 3.44.6 yellow 6.57.8 colorless 8.39.9 none of these indicators
Basic Range Color yellow yellow purple red
ANS: B OBJ: Identify the best indicator for a strong acid-weak base titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 76. Consider the titration of a strong acid with a weak base. Which of the following statements is incorrect? a. The solution is buffered only after the equivalence point. b. The equivalence point would be less than pH = 7.0. c. At the equivalence point, only water and an acidic salt are present. d. Methyl orange (pH color range 3.14.4) could be a suitable indicator. e. The titration of HNO3 with dimethylamine is an example. ANS: A OBJ: Identify an incorrect description of a strong acid-weak base titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
Whitten 10e
Test Bank
706
77. Consider the titration of a weak acid with a strong base. Which of the following statements is incorrect? a. The solution is buffered before the equivalence point. b. The equivalence point would be greater than pH = 7.0. c. At the equivalence point, only water and a basic salt are present. d. KOH added to formic acid is an example of this. e. Methyl orange (pH color range 3.14.4) could be a suitable indicator. ANS: E OBJ: Identify an incorrect description of a weak acid-strong base titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 78. Which acid / base pair would produce an acidic equivalence point? a. HCl / RbOH b. HCl / NH3 c. CH3COOH / KOH d. H2SO4 / Ca(OH)2 e. HNO3 / Ba(OH)2 ANS: B OBJ: Identify the acid-base pair that produces an acidic equivalence point. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 79. What is the [H3O+] in a solution resulting from mixing of 100. mL of 0.100 M HCN and 10.0 mL of 0.100 M KOH? a. 9.1 103 M b. 5.7 106 M c. 3.6 109 M d. 8.2 105 M e. 2.0 108 M ANS: C OBJ: Calculate the hydronium ion concentration of a mixture of weak acid and strong base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 80. Calculate the pH of a solution prepared by adding 60.0 mL of 0.100 M NaOH to 100. mL of 0.100 M CH3COOH solution. a. 4.56 b. 4.92 c. 5.00 d. 5.08 e. 5.16 ANS: B OBJ: Calculate the pH of a mixture of weak acid and strong base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 81. What is the pH of the solution resulting from the addition of 25.0 mL of 0.0100 M NaOH solution to 40.0 mL of 0.0100 M acetic acid, CH3COOH? a. 4.54 b. 4.52 c. 4.94 d. 4.96 e. 5.17 Whitten 10e
Test Bank
707
ANS: D OBJ: Calculate the pH of a mixture of weak acid and strong base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 82. What is the pH at the equivalence point in the titration of 50.0 mL of 0.100 M hydrofluoric acid, HF, with 0.100 M NaOH? a. 5.88 b. 6.08 c. 7.92 d. 8.12 e. 8.56 ANS: C OBJ: Calculate the equivalence point pH of a weak acid-strong base titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 83. Calculate the pH of a solution resulting from the addition of 20.0 mL of 0.100 M HCl to 50.0 mL of 0.100 M NH3. a. 9.26 b. 4.91 c. 9.44 d. 4.60 e. 9.08 ANS: C OBJ: Calculate the pH of a mixture of strong acid and weak base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 84. Calculate the pH of a solution resulting from the addition of 50.0 mL of 0.30 M HNO3 to 50.0 mL of 0.30 M NH3. a. 4.92 b. 7.46 c. 6.18 d. 5.04 e. 8.30 ANS: D OBJ: Calculate the pH of a mixture of strong acid and weak base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 85. Which of the following titrations could the following curve describe?
a. b. c. d. e.
KOH added to HNO3 HCl added to aqueous NH3 HNO3 added to KOH NaOH added to CH3COOH CH3COOH added to aqueous KOH
Whitten 10e
Test Bank
708
ANS: D OBJ: Identify the titration that is consistent with the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 86. Which of the following titrations could the following curve describe?
a. b. c. d. e.
NaOH added to HF HCl added to aqueous NH3 CH3COOH added to aqueous NH3 KOH added to HClO4 HNO3 added to NaOH
ANS: B OBJ: Identify the titration that is consistent with the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 87. Which titration curve could describe the titration of a solution of CH3COOH by addition of a solution of KOH? a.
b.
c.
d.
Whitten 10e
Test Bank
709
e.
ANS: E OBJ: Identify the titration curve of a strong base added to a weak acid. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 88. Which titration curve could describe the titration of a solution of NH2OH by addition of a solution of HNO3? a.
b.
c.
d.
e.
ANS: D OBJ: Identify the titration curve of a strong acid added to a weak base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
Whitten 10e
Test Bank
710
89. When a weak base is titrated with a weak acid, the pH at the equivalence point ____. a. 7 b. is always less than 7 c. is always greater than 7 d. depends on the value of Kb for the base and Ka for the acid e. zero ANS: D OBJ: Estimate the equivalence point pH of a weak acid-weak base titration. TOP: Weak Acid/Weak Base Titration Curves 90. Which indicator could be used to titrate aqueous ammonia with CH3COOH? a. b. c. d. e.
Acid Range Color pH Range pink 1.22.8 blue 3.44.6 yellow 6.57.8 colorless 8.39.9 none of these indicators
Basic Range Color yellow yellow purple red
ANS: E OBJ: Identify the best indicator for a weak acid-weak base titration. TOP: Weak Acid/Weak Base Titration Curves 91. Consider the titration of 30.0 mL of 0.0200 M nitrous acid, HNO2, by adding 0.0500 M aqueous ammonia to it. Which statement is true? The pH at the equivalence point ____. a. is greater than 7 b. is equal to 7 c. is less than 7 d. is less than 0.02 e. zero ANS: C DIF: Harder Question OBJ: Estimate the equivalence point pH of a weak acid-weak base titration. TOP: Weak Acid/Weak Base Titration Curves 92. Consider a titration performed using acetic acid and aqueous ammonia. Which of the following statements is correct? a. The solution is buffered before and after the equivalence point. b. The equivalence point would be at pH > 10. c. Methyl orange (pH color range 3.14.4) could be a suitable indicator. d. There is a rapid change in pH throughout the entire titration. e. An acidic salt is present at the equivalence point. ANS: A OBJ: Identify the correct description of a weak acid-weak base titration. TOP: Weak Acid/Weak Base Titration Curves 93. Consider the titrations of the pairs of aqueous acids and bases listed at the left. Which pair is incorrectly described (at the right) in terms of the acidic, basic, or neutral character of the solutions at the equivalence point?
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Test Bank
711
a. b. c. d. e.
Acid-Base Pair / Character at Equivalence Point HClO + NaOH / acidic HNO3 + Ca(OH)2 / neutral CH3COOH + KOH / basic HCl + NH3 / acidic CH3COOH + NH3 / neutral
ANS: A OBJ: Identify the incorrect equivalence point pH of the acid-base pairs. TOP: Weak Acid/Weak Base Titration Curves 94. Which titration curve could describe the titration of a solution of CH3COOH by addition of a solution of NH3? a.
b.
c.
d.
e.
ANS: A OBJ: Identify the titration curve of a weak base added to a weak acid. TOP: Weak Acid/Weak Base Titration Curves
Whitten 10e
Test Bank
712
95. When a strong base is titrated with a strong acid, the pH at the equivalence point a. is greater than 7. b. is less than 7. c. depends on the value of Kb for the base and Ka for the acid. d. is equal to 7. e. zero ANS: D OBJ: Identify the equivalence point pH of a given acid-base titration combination. TOP: Weak Acid/Weak Base Titration Curves 96. What molar ratio of acetic acid to sodium acetate is required to create a buffer solution having a pH of 4.89 at 25°C? Ka for HC2H3O2 is 1.8 10–5. a. 0.72 b. 1.4 c. 0.56 d. 2.0 e. 2.9 ANS: A DIF: moderate OBJ: Calculate the acid-conjugate base ratio required to achieve the stated pH given the Ka. TOP: Buffering Action 97. A certain weak base B has a base-ionization constant Kb of 2.4 10–4 at 25°C. If strong acid is added to a solution of B, at what pH will [B] = [BH+]? a. 8.5 b. 10.4 c. 7.0 d. 3.6 e. 5.5 ANS: B DIF: moderate OBJ: Calculate the pH at which the concentration of acid and conjugate base are equal. TOP: Preparation of Buffer Solutions 98. What is the pH of a solution that is 0.038 M in HA and also 0.0036 M in NaA? (Ka = 3.8 10–6) a. 8.45 b. 4.40 c. 6.44 d. 5.42 e. 7.18 ANS: B DIF: moderate OBJ: Calculate the pH of a buffer given the concentrations of acid and conjugate base. TOP: Preparation of Buffer Solutions
Whitten 10e
Test Bank
713
99. What mass of sodium hydroxide must be added to 75.0 mL of 0.205 M acetic acid in order to create a buffer with a pH of 4.74? Ka for acetic acid is 1.8 10–5. a. 40 g b. 0.31 g c. 1.0 g d. 0.000055 g e. 0.61 g ANS: B DIF: difficult OBJ: Calculate the mass of strong base required to react with a weak acid to produce a buffer of a given pH. TOP: Preparation of Buffer Solutions 100. What is the pH of a buffer made by combining 175 mL of 0.33 M NaC2H3O2 with 126 mL of 0.48 M HC2H3O2? The Ka of acetic acid is 1.75 10-5. a. 4.74 b. 4.78 c. 5.79 d. 4.69 e. 5.24 ANS: A DIF: difficult OBJ: Calculate the pH of a buffer made by mixing solutions of acid and conjugate base. TOP: Preparation of Buffer Solutions 101. Which of the following will give a buffer with a pH near 4.76 when the acid and conjugate base are mixed in equimolar proportions? Acid NH4+ (from ammonia) HC2H3O2 (acetic acid) HF (hydrofluoric acid) CH3CH2NH3+ (from ethylamine) a. b. c. d. e.
Ka 5.69 10-10 1.75 10-5 6.8 10-4 2.12 10-11
acetic acid hydrofluoric acid ethylamine none ammonia
ANS: A DIF: moderate OBJ: Identify the substance based on weak acid Ka which will produce a buffer with the given pH. TOP: Preparation of Buffer Solutions
Whitten 10e
Test Bank
714
102. Which acid-base combination is depicted by this titration curve? (The marker is located at
titrant volume where the titration solution pH equals 7.)
a. b. c. d. e.
Titration of a weak base with a strong acid. Titration of a weak acid with a strong base. Titration of a strong acid with a strong base. Titration of a strong base with a strong acid. Not enough information provided.
ANS: A DIF: easy OBJ: Identify the acid-base titration given the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 103. Consider the titration of 300.0 mL of 0.410 M NH3 (Kb = 1.8 10–5) with 0.500 M HNO3. After 150.0 mL of 0.500 M HNO3 has been added, what is the pH of the solution? a. 4.94 b. 9.06 c. 6.06 d. 11.06 e. none of these ANS: B DIF: moderate OBJ: Calculate the pH of the solution at a given point in a titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 104. If 40 mL of 0.10 M NaOH is added to 50 mL of 0.20 M HC2H3O2, what is the pH of the resulting solution at 25°C? Ka for HC2H3O2 is 1.8 10–5 at 25°C. a. 10.5 b. 4.3 c. 4.9 d. 2.7 e. 4.6 ANS: E DIF: moderate OBJ: Calculate the pH at a given point in the titration of a weak acid with a strong base. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
Whitten 10e
Test Bank
715
105. Which of the following aqueous mixtures would make a good buffer system? a. 0.25 M HClO4 and 0.22 M NaClO4 b. 0.35 M NH4Br and 0.37 M NH3 c. 0.12 M HCN and 0.21 M HCl d. 0.11 M KOH and 0.29 M KCl e. 0.36 M HNO3 and 0.29 M KNO3 ANS: B OBJ: Identify the mixture that results in a buffer. TOP: Preparation of Buffer Solutions 106. Which of the following aqueous mixtures would make a good buffer system? a. 100.0mL of 0.25M HBr and 50.0mL of 0.22M NaOH b. 100.0mL of 0.35M NH3 and 50.0mL of 0.37M NaOH c. 100.0mL of 0.12M HCN and 100.0mL of 0.21M HCl d. 50.0mL of 0.11M KOH and 50.0mL of 0.29M KCl e. 100.0mL of 0.36M NaBr and 100.0mL of 0.29M KBr ANS: B OBJ: Identify the mixture that results in a buffer. TOP: Preparation of Buffer Solutions 107. What is the pH of a 1.0L solution of 0.445 M hydrocyanic acid, HCN, after 0.191 mol of
potassium cyanide, KCN, is added? (Ka of HCN = 4.0 x 10-10) a. 9.031 b. 9.125 c. 9.750 d. 9.765
e. 10.117
ANS: A OBJ: Calculate the pH of a weak acid solution after addition of conjugate base. TOP: Le Chatelier's Principle and The Common Ion Effect 108. What is the pH of an aqueous solution that contains 0.226 M potassium hydrogen phosphate,
K2HPO4, and 0.451 M potassium dihydrogen phosphate, KH2PO4? (Ka for H2PO4- = 6.2 x 10-8) a. 6.562 b. 6.862 c. 6.908 d. 7.208
e. 7.508
ANS: C OBJ: Calculate the pH of a buffer given the acid and conjugate base concentrations. TOP: Preparation of Buffer Solutions 109. What is the pH of a buffer solution that is 0.270 M in dimethylamine, (CH3)2NH, and 0.449 M
in dimethylammonium chloride, (CH3)2NH2Cl? (Kb for (CH3)2NH = 5.9 x 10-4) a. 3.008 b. 3.450 c. 10.298 d. 10.550 e. 10.771 ANS: D OBJ: Calculate the pH of a buffer given the concentrations of acid and conjugate base. TOP: Preparation of Buffer Solutions
Use the information below to answer the following questions: 1.0 L of a buffer solution is created which is 0.363 M in hydrocyanic acid, HCN, and 0.303 M sodium cyanate, NaCN. Ka for HCN = 4.0 x 10-10
Whitten 10e
Test Bank
716
110. What is the pH of this buffer solution? a. 8.176 b. 8.439 c. 9.319
d. 9.398
e. 9.476
ANS: C OBJ: Calculate the pH of a buffer given the concentrations of acid and conjugate base. TOP: Preparation of Buffer Solutions 111. What is the pH after 0.107 mol of NaOH is added to the buffer solution? a. 9.193 b. 9.319 c. 9.398 d. 9.602 e. 9.928 ANS: D OBJ: Calculate the pH of a buffer after the addition of a strong base. TOP: Preparation of Buffer Solutions 112. What is the pH after 0.089 mol of HCl is added to the buffer solution? a. 8.787 b. 8.866 c. 9.073 d. 9.398 e. 9.723 ANS: C OBJ: Calculate the pH of a buffer after the addition of a strong acid. TOP: Preparation of Buffer Solutions 113. An aqueous solution contains 0.26 M hydrocyanic acid, HCN. One liter of this solution could
be converted to a buffer by the addition of: a. 0.13 mol HBr b. 0.26 mol KBr c. 0.27 mol HBr d. 0.13 mol KOH e. 0.13 mol NH3 ANS: D OBJ: Identify the substance to add to a weak acid to produce a buffer. TOP: Preparation of Buffer Solutions 114. An aqueous solution contains 0.27 M ammonium chloride, NH4Cl. One liter of this solution
could be converted into a buffer by the addition of: a. 0.13 mol HCl b. 0.26 mol KCl c. 0.26 mol NH3 d. 0.27 mol HBr e. 0.27 mol KOH ANS: C OBJ: Identify the substance to add to a weak acid to produce a buffer. TOP: Preparation of Buffer Solutions 115. An aqueous solution contains 0.26 M ammonia, NH3, One liter of this solution could be
converted into a buffer by the addition of: a. 0.27 mol KOH b. 0.26 mol KCl c. 0.27 mol NH4Cl d. 0.27 mol HBr e. 0.13 mol KOH
Whitten 10e
Test Bank
717
ANS: C OBJ: Identify the substance to add to a weak base to produce a buffer. TOP: Preparation of Buffer Solutions 116. Which of the following acids would be best to create a buffer with a pH of 3.75? a. HF, Ka = 7.2 x 10-4 b. C6H5COOH, Ka = 6.3 x 10-5 c. CH3COOH, Ka = 1.8 x 10-5 d. H2S, Ka1 = 1.0 x 10-7 e. HCN, Ka = 4.0 x 10-10 ANS: B OBJ: Identify the best acid for making a buffer with the specified pH. TOP: Preparation of Buffer Solutions
Use the information below to answer the following questions: 25.3 mL of 0.297 M hydroiodic acid, HI, is titrated with 0.188 M sodium hydroxide, NaOH. 117. What is the pH of the solution before any sodium hydroxide is added? a. 0.196 b. 0.527 c. 0.726 d. 0.963 e. 2.125 ANS: B OBJ: Calculate the pH before addition of titrant. TOP: Strong Acid/Strong Base Titration Curves 118. What is the pH of the solution after the addition of 19.9 mL of sodium hydroxide? a. 0.779 b. 0.827 c. 1.079 d. 2.124 e. 2.424 ANS: C OBJ: Calculate the pH after addition of a certain amount of titrant. TOP: Strong Acid/Strong Base Titration Curves 119. What volume of sodium hydroxide is required to reach the equivalence point? a. 16.0 mL b. 20.0 mL c. 25.3 mL d. 40.0 mL e. 41.3 mL ANS: D OBJ: Calculate the volume of titrant required to reach the endpoint. TOP: Strong Acid/Strong Base Titration Curves 120. What will be the pH at the equivalence point? a. above 7.00 c. exactly 7.00 b. below 7.00 d. cannot tell without the Ka for HI ANS: C OBJ: Calculate the pH at the equivalence point. TOP: Strong Acid/Strong Base Titration Curves
Use the information below to answer the following questions: A 24.8 mL solution of 0.399 M aqueous hydrofluoric acid, HF, is titrated with a 0.235 M aqueous potassium hydroxide, KOH, solution. (Ka for HF = 7.2 x 10-4) 121. What volume of potassium hydroxide is required to reach the equivalence point? a. 14.6 mL b. 24.8 mL c. 28.6 mL d. 32.4 mL e. 42.1 mL Whitten 10e
Test Bank
718
ANS: E OBJ: Calculate the volume of titrant required to reach the equivalent point. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 122. What is the pH of the above solution at the equivalence point? a. above 7.00 b. below 7.00 c. exactly 7.00 ANS: A OBJ: Qualitatively determine the pH at the equivalence point. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 123. What is the pH of the solution after the addition of 21.1 mL of potassium hydroxide? a. 3.143 b. 3.444 c. 3.463 d. 3.990 e. 6.711 ANS: A OBJ: Calculate the pH at a specified point in the titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
Use the information below to answer the following questions: A 29.9 mL sample of 0.299 M methylamine, CH3NH2, is titrated with 0.331 M hydroiodic acid, HI. (Kb for methylamine is 4.2 x 10-4) 124. What is the pH of the solution before the addition of any hydroiodic acid? a. 1.951 b. 3.377 c. 5.574 d. 10.623 e. 12.050 ANS: E OBJ: Calculate the pH before addition of titrant. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 125. What is the pH at the midpoint of the titration? a. 3.377 b. 8.318 c. 10.318
d. 10.623
e. 10.714
ANS: D OBJ: Calculate the pH at the specified point in the titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 126. In the titration of a weak monoprotic acid with a strong monoprotic base, what is the pH at the
equivalence point? a. above 7.00 b. below 7.00
c. exactly 7.00 d. cannot tell without a Ka for the acid
ANS: A OBJ: Approximate the pH at the equivalence point of titration. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
Whitten 10e
Test Bank
719
The following pH curve is for the titration of 20.0 mL of a 0.10 M solution of a weak monoprotic acid with a 0.10 M solution of a strong monoprotic base. Data points at 1 mL increments.
127. What is the pH at the midpoint of the titration? a. 2.5 b. 3.7 c. 7.8
d. 11.5
e. 12.0
ANS: A OBJ: Identify the pH at a given point on the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 128. What is the value of Ka for the weak acid? a. 1.3 x 10-2 b. 3.2 x 10-3 c. 1.8 x 10-4
d. 3.1 x 10-8
e. 6.3 x 10-12
ANS: B OBJ: Approximate Ka from the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
The following pH curve is for the titration of 20.0 mL of a 0.10 M solution of a weak monoprotic base with a 0.10 M solution of a strong monoprotic acid. Data points at 1 mL increments.
129. What is the pH at the midpoint of the titration? a. 1.7 b. 1.9 c. 3.3
d. 5.2
e. 6.5
ANS: D OBJ: Identify the pH at a given point on the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves
Whitten 10e
Test Bank
720
130. What is the pH at the equivalence point? a. above 7.00 b. below 7.00
c. exactly 7.00 d. cannot tell without the Kb for the base
ANS: B OBJ: Identify the pH at a given point on the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 131. What is the value of Kb for the weak base? a. 6.3 x 10-6 b. 1.6 x 10-9 c. 5.0 x 10-4
d. 2.0 x 10-11
e. 7.9 x 10-13
ANS: B OBJ: Approximate Kb from the titration curve. TOP: Weak Acid/Strong Base and Weak Base/Strong Acid Titration Curves 132. The pH curve below represents the titration of a ______.
mL of 0.1 M base added
a. strong acid with a strong base b. strong acid with a weak base
c. weak acid with a strong base d. weak acid with a weak base
ANS: D OBJ: Classify the titration given the titration curve. TOP: Titration Curves 133. The pH curve below represents the titration of a ______.
mL of 0.1 M base added
a. strong acid with a strong base b. strong acid with a weak base
c. weak acid with a strong base d. weak acid with a weak base
ANS: A OBJ: Classify the titration given the titration curve. TOP: Titration Curves
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Test Bank
721
134. The pH curve below represents the titration of a ______.
mL of 0.1 M base added
a. strong acid with a weak base b. strong acid with a strong base
c. weak acid with a weak base d. weak acid with a strong base
ANS: C OBJ: Classify the titration given the titration curve. TOP: Titration Curves 135. Which of the following titration curves depicts the titration of a strong acid with a strong
base? a.
c.
b.
d.
ANS: A OBJ: Classify the titration given the titration curve. TOP: Titration Curves CONCEPTUAL 1. Why is it important that many biological fluids are buffered? OBJ: Explain the biological importance of buffers. TOP: Buffering Action
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722
2. Hydrangeas have flowers that have different colors depending on the soil they are planted in. Propose an explanation. OBJ: Explain the natural origins of many acid-base indicators. TOP: Acid-Base Indicators 3. Are all indicators equally good for every titration? If not, explain how you would go about choosing an indicator for a desired experiment. Demonstrate by first choosing a specific acid/base pair and roughly determining the pH of the equivalence point as a basis for the indicator. OBJ: Explain the process of selecting an indicator for an acid-base titration. TOP: Acid-Base Indicators 4. Why don't all acid/base reactions produce a neutral (pH = 7) equivalence point? OBJ: Explain why not all titration curves have an equivalence point at pH = 7. TOP: Titration Curves 5. Relate the Common Ion Effect to Le Chatelier's Principle. DIF: Harder Question OBJ: Compare Le Chatelier's principle and the common ion effect. TOP: Le Chatelier's Principle and The Common Ion Effect 6. Compounds that form acidic or basic solutions in water behave differently in other solvents. How would you expect the equilibrium constants of weak acids and bases to be affected if the solvent were liquid ammonia instead of water? OBJ: Qualitatively compare the equilibrium constants of weak acids and bases in water versus liquid ammonia. TOP: Nonaqueous Solvents
Chapter 20—Ionic Equilibria III: The Solubility Product Principle MULTIPLE CHOICE 1. Which of the following solubility product expressions is incorrect? a. b. c. d. e. ANS: C OBJ: Identify the incorrect Ksp expression. TOP: Solubility Product Constants 2. Which of the following solubility product expressions is incorrect? a. Cu2S, Ksp = [Cu+][S2] Whitten 10e
Test Bank
723
b. c. d. e.
Co2S3, Ksp = [Co3+]2[S2]3 Ni(CN)2, Ksp = [Ni2+][CN]2 AuI, Ksp = [Au+][I] Cr(OH)3, Ksp = [Cr3+][OH]3
ANS: A OBJ: Identify the incorrect Ksp expression. TOP: Solubility Product Constants 3. Which of the following solubility product expressions is incorrect?
a. b. c. d. e.
Compound / Ksp Expression gold(III) chloride / [Au3+][Cl]3 calcium fluoride / [Ca2+][F]2 lead(II) iodide / [Pb2+][I]2 zinc phosphate / [Zn2+][PO43] silver chromate / [Ag+]2[CrO42]
ANS: D OBJ: Identify the incorrect Ksp expression. TOP: Solubility Product Constants
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Test Bank
724
4. Which of the following solubility product expressions is correct? a. b. c. d. e. ANS: B DIF: Harder Question OBJ: Identify the correct Ksp expression. TOP: Solubility Product Constants 5. Which statement about solubility product constant, Ksp, is false? a. It is a constant at a given temperature. b. It equals the equilibrium constant in equilibria that involve slightly soluble compounds in water. c. The concentration of the solid is not included in the solubility product expression. d. The solubility product expression is the product of the concentrations of the compound's constituent ions. e. It is based on the solubility product principle. ANS: D OBJ: Identify the incorrect description of Ksp. TOP: Solubility Product Constants 6. If X = the molar solubility (mol/L) of Ni(OH)2, which of the following represents the correct relationship between the Ksp and X, the molar solubility of Ni(OH)2? a. Ksp = 4 X2 b. Ksp = 4 X3 c. Ksp = 2 X2 d. Ksp = X3 e. Ksp = X2 ANS: B OBJ: Write the Ksp of a compound in terms of a single variable. TOP: Determination of Solubility Product Constants 7. If X = the molar solubility (mol/L) of Ca3(PO4)2, which of the following represents the correct relationship between the Ksp and X, the molar solubility of Ca3(PO4)2? a. Ksp = X2 b. Ksp = 27 X5 c. Ksp = 4 X2 d. Ksp = 108 X5 e. Ksp = 16 X3 ANS: D OBJ: Write the Ksp of a compound in terms of a single variable. TOP: Determination of Solubility Product Constants
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Test Bank
725
8. The molar solubility of BaCO3 is 9.0 105 M at 25C. What is the solubility product constant for BaCO3? a. 1.2 108 b. 8.1 109 c. 5.3 1012 d. 4.0 1015 e. 6.7 1011 ANS: B OBJ: Calculate the Ksp given molar solubility. TOP: Determination of Solubility Product Constants 9. Calculate the solubility product constant for aluminum hydroxide. Its molar solubility is 2.9 109 mole per liter at 25C. a. 9.8 1026 b. 4.9 1026 c. 7.1 1035 d. 2.1 1034 e. 1.9 1033 ANS: E OBJ: Calculate the Ksp given molar solubility. TOP: Determination of Solubility Product Constants 10. At 25C, 1.4 105 mole of Cd(OH)2 dissolves to give 1.0 liter of saturated aqueous solution. What is the solubility product for Cd(OH)2? a. 1.7 105 b. 2.9 1010 c. 1.1 1014 d. 5.8 1015 e. 4.1 1012 ANS: C OBJ: Calculate the Ksp given molar solubility. TOP: Determination of Solubility Product Constants 11. One liter of saturated zinc hydroxide solution contains 0.00022 g of dissolved Zn(OH)2. Calculate Ksp for Zn(OH)2. a. 4.8 1012 b. 2.6 1016 c. 4.5 1017 d. 7.1 1014 e. 1.1 1017 ANS: C OBJ: Calculate the Ksp given solubility in g/L. TOP: Determination of Solubility Product Constants
Whitten 10e
Test Bank
726
12. The solubility of Ce(OH)3 is 9.9 104 g per liter at 25C. Calculate the solubility product for Ce(OH)3. a. 5.2 106 b. 2.0 1020 c. 7.3 1020 d. 4.0 1014 e. 1.6 1018 ANS: B OBJ: Calculate the Ksp given solubility in g/L. TOP: Determination of Solubility Product Constants 13. The solubility of Fe(OH)2 is 3.00 103 g in 2.00 liters at 18C. What is its Ksp at 18C? a. 4.92 1012 b. 6.03 109 c. 2.44 1010 d. 1.86 1014 e. 2.11 1011 ANS: D OBJ: Calculate the Ksp given solubility in g/L. TOP: Determination of Solubility Product Constants 14. The solubility of cerium periodate, Ce(IO4)4, is 0.015 g/mL of water at 25C. Calculate its solubility product constant. Its formula weight is 904 g/mol. a. 8.1 1014 b. 3.2 107 c. 9.4 1024 d. 4.1 1012 e. 6.9 1022 ANS: B OBJ: Calculate the Ksp given solubility in g/L. TOP: Determination of Solubility Product Constants 15. Magnesium hydroxide is a slightly soluble substance. If the pH of a saturated solution of Mg(OH) 2 is 10.49 at 25C, calculate Ksp for Mg(OH)2. a. 8.8 1016 b. 4.2 1015 c. 6.0 1010 d. 4.4 1014 e. 1.5 1011 ANS: E OBJ: Calculate the Ksp of a metal hydroxide given the saturated solution pH. TOP: Determination of Solubility Product Constants
Whitten 10e
Test Bank
727
16. How is the molar solubility, X (mol/L), related to the Ksp for Fe2S3; i.e., X = ____? a.
b.
c.
d. (Ksp)1/5 e. (Ksp)1/2 ANS: C OBJ: Write the Ksp of a compound in terms of a single variable and solve for this variable. TOP: Uses of Solubility Product Constants 17. Which of the following has the lowest molar solubility in water at 25C? a. Ni(CN)2, Ksp = 3.0 1023 b. ZnS, Ksp = 1.1 1021 c. PbS, Ksp = 8.4 1028 d. Co3(AsO4)2, Ksp = 7.6 1029 e. CaF2, Ksp = 3.9 1016 ANS: C OBJ: Identify the compound with the lowest molar solubility given Ksp's. TOP: Uses of Solubility Product Constants 18. Calculate the molar solubility of AgCl at 25C. Ksp = 1.8 1010. a. 1.3 105 M b. 1.7 105 M c. 4.2 105 M d. 4.6 105 M e. 1.8 1010 M ANS: A OBJ: Calculate molar solubility given Ksp. TOP: Uses of Solubility Product Constants 19. The value of Ksp for SrSO4 is 2.8 107. What is the molar solubility of SrSO4? a. 7.6 107 M b. 5.8 1013 M c. 5.3 104 M d. 5.7 103 M e. 1.3 108 M ANS: C OBJ: Calculate molar solubility given Ksp. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
728
20. The Ksp for magnesium arsenate is 2.1 1020 at 25C. What is the molar solubility of Mg3(AsO4)2 at 25C? a. 6.7 103 M b. 3.6 104 M c. 4.5 105 M d. 7.0 105 M e. 1.4 106 M ANS: C OBJ: Calculate molar solubility given Ksp. TOP: Uses of Solubility Product Constants 21. Ksp for silver arsenate is 1.1 1020. What is the molar solubility of Ag3AsO4? a. 2.2 107 M b. 4.5 106 M c. 6.2 108 M d. 4.1 107 M e. 1.0 1010 M ANS: B OBJ: Calculate molar solubility given Ksp. TOP: Uses of Solubility Product Constants 22. Calculate the molar solubility of nickel phosphate at 25C. Its Ksp is 5.0 1031. a. 3.4 107 M b. 8.7 107 M c. 6.1 107 M d. 7.1 1016 M e. 5.0 1011 M ANS: A OBJ: Calculate molar solubility given Ksp. TOP: Uses of Solubility Product Constants 23. Calculate the concentration of OH ions in a saturated Mn(OH)2 solution. The solubility product for Mn(OH)2 is 4.6 1014. a. 1.0 105 M b. 2.0 105 M c. 1.6 105 M d. 3.2 105 M e. 4.5 105 M ANS: E OBJ: Calculate the molar solubility of an ion given Ksp. TOP: Uses of Solubility Product Constants 24. Calculate the pH in a saturated Mn(OH)2 solution. The solubility product for Mn(OH)2 is 4.6 1014. a. 9.00 b. 9.25 c. 9.35 d. 9.50 e. 9.65
Whitten 10e
Test Bank
729
ANS: E DIF: Harder Question OBJ: Calculate pH given Ksp. TOP: Uses of Solubility Product Constants 25. Calculate the concentration of F ions in saturated CaF2 solution at 25C. Ksp = 3.9 1011. a. 2.1 104 M b. 4.3 104 M c. 0.016 M d. 0.032 M e. 0.10 M ANS: B OBJ: Calculate the molar solubility of an ion given Ksp. TOP: Uses of Solubility Product Constants 26. Calculate [Al3+] in a saturated Al(OH)3 solution at 25C. Ksp = 1.9 1033 a. 6.6 109 M b. 2.9 109 M c. 1.5 1017 M d. 8.4 1018 M e. 1.5 107 M ANS: B OBJ: Calculate the molar solubility of an ion given Ksp. TOP: Uses of Solubility Product Constants 27. Calculate the pH of a saturated aqueous solution of Co(OH)2. Ksp is 2.5 1016. a. 8.60 b. 8.90 c. 9.10 d. 9.20 e. 9.40 ANS: B DIF: Harder Question OBJ: Calculate pH given Ksp. TOP: Uses of Solubility Product Constants 28. What mass of Zn(OH)2 is contained in 1.0 liter of saturated solution? Ksp = 4.5 1017. a. 0.00011 g b. 0.00022 g c. 0.00044 g d. 0.010 g e. 0.016 g ANS: B OBJ: Calculate solubility in grams of compound per liter solution given Ksp. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
730
29. What mass of CaF2 is contained in 1.0 liter of saturated solution? Ksp = 3.9 1011. a. 0.0010 g b. 0.0028 g c. 0.0034 g d. 0.010 g e. 0.017 g ANS: E OBJ: Calculate solubility in grams of compound per liter solution given Ksp. TOP: Uses of Solubility Product Constants 30. How many grams of Mn(OH)3 will dissolve in 1350 mL of water at 25C? Ksp = 1.0 1036 a. 4.6 108 g b. 6.3 108 g c. 5.9 1010 g d. 1.4 107 g e. 9.3 107 g ANS: B OBJ: Calculate solubility in grams of compound per stated volume given Ksp. TOP: Uses of Solubility Product Constants 31. Calculate the solubility of Mg(OH)2 in g per 100. mL of water. Ksp = 1.5 1011. a. 9.1 104 g/100. mL b. 3.6 103 g/100. mL c. 6.6 105 g/100. mL d. 1.8 103 g/100. mL e. 5.0 106 g/100. mL ANS: A DIF: Harder Question OBJ: Calculate solubility in grams of compound per stated volume given Ksp. TOP: Uses of Solubility Product Constants 32. The solubility product constant for MgF2 is 6.4 109. How many grams of MgF2 will dissolve in 150 mL of H2O at 25C? a. 1.1 102 g b. 5.8 103 g c. 4.7 101 g d. 6.0 104 g e. 2.2 103 g ANS: A DIF: Harder Question OBJ: Calculate solubility in grams of compound per stated volume given Ksp. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
731
33. Given the following values of Ksp for four slightly soluble sulfides at 25C. Sulfide CdS CuS
Ksp 3.6 1029 8.7 1036
Sulfide PbS MnS
Ksp 8.4 1028 5.1 1015
Which one of the following ions exists in the lowest concentration in a solution in which the sulfide ion concentration had been fixed at some (fairly large) constant value at 25C? a. Cd2+ b. Cu2+ c. Pb2+ d. Mn2+ e. Cannot be answered without knowing the sulfide ion concentration. ANS: B OBJ: Apply the common-ion effect to determine the metal ion in lowest concentration. TOP: Uses of Solubility Product Constants 34. AgCl would be least soluble at 25C in ____. a. pure water b. 0.1 M CaCl2 c. 0.1 M HCl d. 0.1 M HNO3 e. It is equally soluble in all of these substances. ANS: B OBJ: Apply the common-ion effect to identify the solution in which a compound would be least soluble. TOP: Uses of Solubility Product Constants 35. Ksp for lead fluoride is 3.7 108. What is the molar solubility of PbF2 in 0.10 M NaF? a. 4.6 105 M b. 1.9 104 M c. 3.7 107 M d. 3.7 106 M e. 8.5 108 M ANS: D OBJ: Calculate molar solubility in a solution with an ion in common. TOP: Uses of Solubility Product Constants 36. How many grams of AgCl will dissolve in 1.0 L of 0.25 M CaCl2? Ksp (AgCl) = 1.8 1010 a. 3.6 1010 b. 1.0 107 c. 5.1 108 d. 1.3 108 e. 7.2 1010 ANS: C OBJ: Calculate solubility in grams per liter in a solution with an ion in common. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
732
37. How many grams of MgF2 will dissolve in 150. mL of 0.100 M NaF solution? Ksp for MgF2 = 6.4 109 a. 6.2 107 g b. 4.1 106 g c. 1.0 105 g d. 6.0 106 g e. 9.3 107 g ANS: D OBJ: Calculate solubility in grams per stated volume with an ion in common. TOP: Uses of Solubility Product Constants 38. How many grams of BaCO3 will dissolve in 853 mL of 0.15 M BaCl2? a. b. c. d. e.
= 8.1 109
1.1 105 g 4.6 108 g 5.5 108 g 8.1 109 g 9.1 106 g
ANS: E OBJ: Calculate solubility in grams per stated volume with an ion in common. TOP: Uses of Solubility Product Constants 39. If aqueous solutions of the following pairs of compounds are mixed, which combination might result in the formation of a precipitate? a. MgCl2 + Na2S b. NH4ClO4 + K2S c. BaCl2 + Ca(CH3COO)2 d. CrCl3 + Ni(NO3)2 e. Na3PO4 + Cr(NO3)3 ANS: E OBJ: Identify the combination of compounds that might produce a precipitate. TOP: Uses of Solubility Product Constants 40. We mix each of the following pairs of solutions together. In which case would we not expect a precipitate (solid) to be formed? a. KCl solution and AgNO3 solution b. Pb(NO3)2 solution and H2SO4 solution c. CuCl2 solution and Na2S solution d. CaCl2 solution and HNO3 solution e. A precipitate would be likely to form in every case. ANS: D OBJ: Identify the combination of compounds that would not produce a precipitate. TOP: Uses of Solubility Product Constants 41. When we mix together, from separate sources, the ions of a slightly soluble ionic salt, the salt will begin to precipitate if Qsp ____ Ksp, and will continue to precipitate until Qsp ____ Ksp. a. is greater than; equals b. is less than; is greater than c. is less than; equals d. equals; is less than e. equals; is greater than Whitten 10e
Test Bank
733
ANS: A OBJ: Compare the reaction quotient to Ksp before and after equilibrium is established. TOP: Uses of Solubility Product Constants 42. The Ksp for Fe(IO3)3 is 1014. We mix two solutions, one containing Fe3+ and one containing IO3 ions at 25C. At the instant of mixing, [Fe3+] = 102 M and [IO3] = 105 M. Which one of the following statements is true? a. A precipitate forms, because Qsp > Ksp. b. A precipitate forms, because Qsp < Ksp. c. No precipitate forms, because Qsp > Ksp. d. No precipitate forms, because Qsp < Ksp. e. None of these statements is true. ANS: D OBJ: Compare the reaction quotient to Ksp at the conditions given. TOP: Uses of Solubility Product Constants 43. The Ksp for Zn3(AsO4)2 is 1.1 1027. When 100 mL of 5.5 104 M Zn2+ is mixed with 50 mL of 1.2 104 M AsO43, which of the following statements is true? a. A precipitate forms, because Qsp > Ksp. b. A precipitate forms, because Qsp < Ksp. c. No precipitate forms, because Qsp > Ksp. d. No precipitate forms, because Qsp < Ksp. e. None of these statements is true. ANS: A OBJ: Compare the reaction quotient to Ksp at the conditions given. TOP: Uses of Solubility Product Constants 44. Calculate the [Ca2+] required to start the precipitation of calcium fluoride, CaF2, from a solution containing 0.0025 M F at 25C. Ksp for CaF2 = 3.9 1011. a. 6.4 107 M b. 5.2 1010 M c. 4.8 103 M d. 6.2 106 M e. 1.6 108 M ANS: D OBJ: Calculate the molar solubility of an ion in a solution of a counter ion with which it can form an insoluble compound. TOP: Uses of Solubility Product Constants 45. What concentration of Al3+ must be exceeded in a solution buffered at pH = 4.80 in order to initiate precipitation of Al(OH)3 at 25C? Ksp for Al(OH)3 = 1.9 1033. a. 6.3 1010 M b. 7.6 106 M c. 4.1 104 M d. 5.3 107 M e. 2.2 108 M ANS: B OBJ: Calculate the molar solubility of an ion in a solution of a counter ion with which it can form an insoluble compound. TOP: Uses of Solubility Product Constants Whitten 10e
Test Bank
734
46. A solution contains 0.025 M Ba2+. If 9.7 g of Na2CO3 is added to 1.0 L of this solution, what percentage of Ba2+ remains in solution? Assume no change in volume occurs. = 8.1 109. a. b. c. d. e.
27.3 % 6.6 % 0.00049 % 0.000012 % 0.025 %
ANS: C OBJ: Calculate the % of an ion not precipitated. TOP: Uses of Solubility Product Constants 47. Calculate the concentration of carbonate ion in a saturated solution of calcium carbonate to which calcium chloride has been added until [Ca2+] = 0.015 M at 25C. Ksp for CaCO3 = 2.8 109. a. 4.2 1011 M b. 1.9 107 M c. 1.2 105 M d. 6.3 1013 M e. 1.5 102 M ANS: B OBJ: Calculate the molar solubility of an ion in a solution of a counter ion with which it can form an insoluble compound. TOP: Uses of Solubility Product Constants 48. What is the minimum concentration of iodide ion required to limit the concentration of lead ion in solution to a maximum of 1.0 106 M? Ksp for PbI2 is 8.7 109. a. 1.7 102 M b. 1.8 101 M c. 7.6 105 M d. 8.7 103 M e. 9.3 102 M ANS: E OBJ: Calculate the minimum ion concentration required to achieve the stated concentration of a counter ion with which it can form an insoluble compound. TOP: Uses of Solubility Product Constants 49. An aqueous solution of silver bromide is adjusted so that the concentration of silver ion in solution is limited to a maximum of 1.0 109 M. Which of the following statements about the solution is false? Ksp for AgBr is 3.3 1013. a. The minimum concentration of bromide needed for this limit is 3.3 104 M. b. If the concentration of bromide is 1.5 106, no precipitate will form. c. If the concentration of bromide is held precisely at 3.3 104, neither forward nor reverse process is favored. d. Adjusting the bromide concentration always effects the silver concentration. e. If [Br] is raised to 1 103 M, the silver concentration drops to 3.3 1010. ANS: D OBJ: Identify the incorrect description of a solid-solution equilibrium. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
735
50. Which of the following responses contains all of the true statements? I. An ion may never be completely precipitated from solution, even when the precipitating reagent is used in large excess. II. If solid NaCl is added slowly to a saturated solution of NiS in contact with solid NiS, nothing significant will happen to the NiS. III. Consider two relatively insoluble 1:1 salts (i.e., one cation and one anion per formula unit) containing the same cation, whose solubility products differ by 104. More than 90% of one anion can be precipitated before the other precipitates when the common cation is added to a solution of the two anions. a. b. c. d. e.
I and III I and II II and III III I, II, and III
ANS: E OBJ: Identify the correct descriptions of solid-solution equilibria. TOP: Fractional Precipitation 51. A solution is 0.012 M in Pb(NO3)2 and 0.20 M in Sr(NO3)2. Solid Na2SO4 is added until a precipitate just begins to form. The precipitate is ____ and the concentration of sulfate ion at this point is ____. Ksp for PbSO4 is 1.8 108 and for SrSO4 is 2.8 107. a. SrSO4; 2.6 107 M b. SrSO4; 8.3 107 M c. PbSO4; 6.3 106 M d. PbSO4; 1.5 106 M e. SrSO4; 1.4 106 M ANS: D OBJ: Identify the precipitate formed and calculate the concentration of the precipitating ion when precipitation begins. TOP: Fractional Precipitation 52. A solution contains 0.05 M Au+, 0.05 M Cu+, and 0.05 M Ag+ ions. When solid NaCl is added to the solution, what is the order in which the chloride salts will begin to precipitate? Ksp(AgCl) = 1.8 1010, Ksp(AuCl) = 2.0 1013, Ksp(CuCl) = 1.9 107 a. AuCl > AgCl > CuCl b. AuCl > AgCl > NaCl c. AgCl > CuCl > AuCl d. CuCl > AgCl > AuCl e. NaCl > CuCl > AgCl ANS: A OBJ: Determine the order of precipitation. TOP: Fractional Precipitation
Whitten 10e
Test Bank
736
53. Solid Na2SO4 is added to a solution that is 0.30 M in both Sr2+ and Pb2+. Assuming no volume change, what will be the [Pb2+] at the point at which SrSO4 just begins to precipitate at 25C? Ksp for SrSO4 = 2.8 107 and for PbSO4 = 1.8 108. a. 0.24 M b. 0.16 M c. 0.30 M d. 0.019 M e. 0.040 M ANS: D OBJ: Calculate the molar concentration of an ion in a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 54. When 10.0 g Na2CO3 is added to 1.0 L of a solution containing 0.05 M of each Mg2+, Ca2+, Sr2+, and Ba2+, which cation concentration is lowest after the carbonate salts precipitate? = 4.0 105, a. b. c. d. e.
= 4.8 109,
= 9.4 1010,
= 8.1 109
Mg2+ Ca2+ Na+ Sr2+ Ba2+
ANS: D OBJ: Identify the least soluble compound given Ksp's. TOP: Fractional Precipitation 55. Solid sodium chloride is added to a solution that is 0.0100M in silver nitrate and 0.0100 M in lead(II) nitrate. Assuming no volume change, calculate the percent of silver that will be precipitated when the lead chloride just begins to precipitate. Ksp = 1.8 1010 for AgCl Ksp = 1.7 105 for PbCl2 a. b. c. d. e.
99.8941% 99.9996% 99.9989% 95.9000% 98.9413%
ANS: B DIF: Harder Question OBJ: Calculate the % an ion precipitated from a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 56. The solubility product for barium chromate, BaCrO4, is 2.0 1010 and the solubility product for lead chromate, PbCrO4, is 1.8 1014. If solid Na2CrO4 is added slowly to a solution which is 0.010 M in Ba(NO3)2 and 0.010 M in Pb(NO3)2, what will the concentration of Pb2+ be just before BaCrO4 begins to precipitate? Assume no volume change due to the addition of solid Na2CrO4. a. 4.0 107 M b. 2.0 108 M c. 1.8 1014 M d. 9.0 107 M e. 1.4 105 M
Whitten 10e
Test Bank
737
ANS: D OBJ: Calculate the molar concentration of an ion in a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 57. A solution is 0.0010 M in both Ag+ and Au+. Some solid NaCl is added slowly until the second solid compound just begins to precipitate. What is the concentration of Au+ ions at this point? Ksp for AgCl = 1.8 1010 and for AuCl is 2.0 1013. a. 2.0 1010 M b. 4.5 107 M c. 1.8 107 M d. 3.0 104 M e. 1.1 106 M ANS: E OBJ: Calculate the molar concentration of an ion in a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 58. If solid AgNO3 is slowly added to a solution that is 0.050 M in NaI and 0.12 M in NaCl, what is the concentration of I when AgCl just begins to precipitate? Ksp for AgCl = 1.8 1010, Ksp for AgI = 1.5 1016 a. 1.0 109 M b. 9.2 109 M c. 8.5 108 M d. 1.0 107 M e. 6.7 107 M ANS: D OBJ: Calculate the molar concentration of an ion in a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 59. At 25C the Ksp for MgCO3 is 4.0 105 and that for BaCO3 is 8.1 109. Assuming both magnesium ions and barium ions are present in 1.0 103 M concentrations, what is the equilibrium concentration of carbonate ions that will precipitate the maximum concentration of Ba2+ without precipitating any Mg2+ at 25C? a. 4.0 102 M b. 4.2 103 M c. 3.5 103 M d. 5.8 102 M e. 3.2 102 M ANS: A OBJ: Calculate the molar concentration of an ion in a mixture before the second of two ions with which it precipitates begins to precipitate. TOP: Fractional Precipitation
Whitten 10e
Test Bank
738
60. Solid lead nitrate is added slowly to a solution that is 0.010 M in sodium sulfate and 0.010 M in sodium chromate at 25C. What percent of the chromate ions remain in solution, i.e., unprecipitated, just before lead sulfate begins to precipitate? Ksp for PbSO4 = 1.8 108, Ksp for PbCrO4 = 1.8 1014 a. 0.18% b. 0.018% c. 0.0018% d. 0.00010% e. 0.00018% ANS: D OBJ: Calculate the % of an ion from a mixture remaining in solution when the other ion begins to precipitate. TOP: Fractional Precipitation 61. Solid silver nitrate is added slowly to a solution that is 0.0010 M in sodium chloride and 0.0010 M in sodium bromide. What % of the bromide ions remain in solution, i.e., unprecipitated, just before silver chloride begins to precipitate? Ksp for AgCl = 1.8 1010, Ksp for AgBr = 3.3 1013 a. 0.18% b. 0.018% c. 0.0010% d. 0.00010% e. 0.0018% ANS: A OBJ: Calculate the % of an ion from a mixture remaining in solution when the other ion begins to precipitate. TOP: Fractional Precipitation 62. A solution is 1.0 103 M in Mg(NO3)2 and 1.0 103 M in Cd(NO3)2. Some solid NaOH is added slowly. What percentage of the Cd2+ originally in solution has precipitated as Cd(OH)2 at the point at which Mg(OH)2 just begins to precipitate? Ksp for Cd(OH)2 is 1.2 1014 and Ksp for Mg(OH)2 is 1.5 1011. a. 98.12% b. 99.92% c. 99.63% d. 98.73% e. 99.52% ANS: B OBJ: Calculate the % an ion precipitated from a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 63. A solution is 1.0 104 M in sodium sulfate, Na2SO4, and 1.0 104 M in sodium selenate, Na2SeO4. Solid barium chloride, BaCl2, is added slowly and one of the two salts, BaSO4 or BaSeO4, begins to precipitate. What percentage of the anion that precipitates first has precipitated at the point at which the second anion begins to precipitate? Ksp for BaSO4 is 1.1 1010 and for BaSeO4 is 2.8 1011. a. 10% b. 25% c. 90% d. 75% e. 50%
Whitten 10e
Test Bank
739
ANS: D DIF: Harder Question OBJ: Calculate the % an ion precipitated from a mixture when the other ion begins to precipitate. TOP: Fractional Precipitation 64. Solid AgNO3 is added slowly to a solution which is 0.0010 M in NaCl and 0.0010 M in NaBr. The Ksp for AgCl is 1.8 1010 and the Ksp for AgBr is 3.3 1013. What concentration of Br remains in solution when 50.% of the Cl has precipitated? a. 3.6 107 M b. 1.2 108 M c. 3.3 1010 M d. 9.2 107 M e. 4.2 109 M ANS: D OBJ: Calculate the % of an ion from a mixture remaining in solution when a given amount of the other ion has precipitated. TOP: Fractional Precipitation 65. A solution contains 0.10 M Ca2+ and 0.10 M Mg2+. What pH range would result in only Mg(OH)2 precipitating? Ksp for Ca(OH)2 is 6.5 106 and for Mg(OH)2 is 7.1 1012. a. 3.85 < pH < 9.82 b. 8.92 < pH < 11.91 c. 2.85 < pH < 8.81 d. 9.00 < pH < 13.00 e. 8.62 < pH < 11.61 ANS: B DIF: Harder Question OBJ: Determine the pH range which will precipitate only one of a mixture of ions. TOP: Fractional Precipitation 66. If a solution is 0.10 M in magnesium nitrate and then is also made 0.10 M in aqueous ammonia, what possible precipitate could form? a. Mg(NO3)2 b. NH4NO3 c. Mg(OH)2 d. NH4OH e. No possible precipitate ANS: C OBJ: Identify the precipitate possible given the reactants. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 67. If a solution of 0.10 M HCN is mixed with a solution of 0.10 M AgNO3, what possible precipitate may form? a. Ag2CN b. NH4NO3 c. NH4OH d. AgCN e. None is possible.
Whitten 10e
Test Bank
740
ANS: D OBJ: Identify the precipitate possible given the reactants. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 68. If a solution of 0.10 M HI is mixed with a solution of 0.10 M Sn(ClO3)2, what possible precipitate may form? a. Sn(ClO3)2 b. SnI2 c. HClO3 d. SnI4 e. None is possible. ANS: B OBJ: Identify the precipitate possible given the reactants. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 69. What concentration of aqueous NH3 is necessary to just start precipitation of Mn(OH)2 from a 0.020 M solution MnSO4? Kb for NH3 is 1.8 105 and Ksp for Mn(OH)2 is 4.6 1014. a. 1.4 105 M b. 3.7 107 M c. 1.6 106 M d. 1.3 107 M e. 8.4 102 M ANS: D OBJ: Calculate the molar concentration of weak base required to precipitate a metal ion. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 70. If a solution is to be made 0.010 M in Mg(NO3)2 and 0.20 M in aqueous NH3, how many mol/L of NH4Cl are required to prevent the precipitation of Mg(OH)2 at 25C? The Kb for aqueous NH3 is 1.8 105 and the Ksp for Mg(OH)2 is 1.5 1011. a. 0.054 b. 0.56 c. 0.092 d. 1.8 e. 0.86 ANS: C OBJ: Calculate the molar concentration of weak acid required to prevent precipitation of a metal ion from a solution of weak base. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 71. What minimum concentration of ammonium ion (from ammonium chloride) is necessary to prevent the precipitation of Mn(OH)2 from a solution which is to be made 0.030 M in Mn(NO3)2 and 0.030 M in aqueous ammonia? The solubility product for Mn(OH)2 is 4.6 1014, and the ionization constant for aqueous ammonia is 1.8 105. a. 0.18 M b. 0.44 M c. 0.54 M d. 0.72 M e. 0.88 M
Whitten 10e
Test Bank
741
ANS: B OBJ: Calculate the molar concentration of weak acid required to prevent precipitation of a metal ion from a solution of weak base. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 72. If 1.0 liter of solution is to be made 0.010 M in Mg(NO3)2 and 0.10 M in aqueous ammonia, how many moles of NH4Cl are necessary to prevent the precipitation of magnesium hydroxide? The solubility product for Mg(OH)2 is 1.5 1011, and the ionization constant for aqueous ammonia is 1.8 105. a. 0.018 mol b. 0.016 mol c. 0.020 mol d. 0.040 mol e. 0.046 mol ANS: E OBJ: Calculate the moles of weak acid required to prevent precipitation of a metal ion from a solution of weak base. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 73. A 2.0-liter volume of a solution is 4.2 105 M in Mn(NO3)2 and 0.10 M in ammonia. How many moles of NH4NO3 are required to prevent the precipitation of Mn(OH)2? Ksp for Mn(OH)2 = 4.6 1014 and Kb for NH3 = 1.8 105. a. 0.62 mol b. 0.11 mol c. 0.048 mol d. 0.24 mol e. 0.033 mol ANS: B OBJ: Calculate the moles of weak acid required to prevent precipitation of a metal ion from a solution of weak base. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 74. A 50.0 mL-sample of 1.8 M aqueous NH3 is mixed with an equal volume of a solution containing 0.010 mol of MgCl2. What mass of NH4Cl must be added to the resulting solution to prevent precipitation of Mg(OH)2? Ksp for Mg(OH)2 = 1.5 1011 and Kb for NH3 = 1.8 105. a. 4.4 g b. 5.7 g c. 6.2 g d. 6.6 g e. 7.1 g ANS: E DIF: Harder Question OBJ: Calculate the grams of weak acid required to prevent precipitation of a metal ion from a solution of weak base. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds
Whitten 10e
Test Bank
742
75. The solubility of magnesium carbonate, MgCO3, can be increased by acidifying the solution in which MgCO3 is suspended. This is an example of dissolution via ____. a. formation of a weak electrolyte b. reduction of the anion c. oxidation of the anion d. formation of a complex ion e. changing an ion to another species which is not a weak electrolyte ANS: A OBJ: Complete the description of a dissolution process. TOP: Dissolving Precipitates 76. Which of the following salts would not be expected to be more soluble in acidic solution than in pure water? a. Mg(OH)2 b. ZnS c. BaCO3 d. PbI2 e. AgF ANS: D OBJ: Identify the salt whose solubility is not effected by acid. TOP: Dissolving Precipitates 77. Which of the following salts would be expected to be more soluble in acidic solution than in pure water? a. AgBr b. Hg2I2 c. CaF2 d. PbCl2 e. BaSO4 ANS: C OBJ: Identify the salt whose solubility is not effected by acid. TOP: Dissolving Precipitates 78. How might one test if PbS has been completely precipitated from a saturated H2S solution? a. heat the solution b. add a strong acid c. add a weak acid d. add more H2S e. add a weak base ANS: E OBJ: Identify a test to determine if a metal ion has been completely precipitated. TOP: Dissolving Precipitates 79. Which of the following is a technique that could increase the solubility of CuS? a. Reducing the S2 to sulfur by adding nitric acid. b. Conversion of S2 to H2S by adding HCl. c. Conversion of Cu2+ to a complex ion by adding NH3. d. All three would increase the solubility. e. None of these would increase the solubility.
Whitten 10e
Test Bank
743
ANS: D OBJ: Identify methods that increase the solubility of a metal ion. TOP: Dissolving Precipitates 80. Calculate the number of moles of ammonia needed to dissolve 0.0010 mole of silver chloride in 4000. mL of solution at 25C. Ksp for AgCl is 1.8 1010 and the dissociation constant for [Ag(NH3)2]+ is 6.3 108. a. 0.16 mole b. 0.021 mole c. 14 moles d. 0.28 mole e. 1.5 moles ANS: B DIF: Harder Question OBJ: Calculate the moles of complexing agent required to dissolve a precipitate. TOP: Dissolving Precipitates 81. Calculate the minimum concentration of NH3 necessary in 1.0 liter of solution to just dissolve 3.0 103 mole of AgBr at 25C. Ksp for AgBr = 3.3 1013, Kd for [Ag(NH3)2]+ = 6.3 108. a. 6.2 M b. 8.6 M c. 1.3 M d. 0.18 M e. 0.067 M ANS: C OBJ: Calculate the concentration of complexing agent required to dissolve a precipitate. TOP: Dissolving Precipitates 82. What concentration of NH3 must be present in 4.0 103 M Ag+ to prevent the precipitation of AgCl when [Cl] reaches 1.0 103 M? Ksp for AgCl = 1.8 1010 and Kd for [Ag(NH3)2]+ = 6.3 108. a. 7.4 104 M b. 6.1 103 M c. 4.5 102 M d. 1.6 102 M e. 8.5 101 M ANS: C DIF: Harder Question OBJ: Calculate the concentration of complexing agent required to prevent precipitation. TOP: Dissolving Precipitates 83. The cations in many slightly soluble compounds can form complex ions; this results in the ____ of the slightly soluble compound as ____ are formed with molecules and ions such as NH3, CN, and the halides. a. precipitation; weak electrolytes b. dissolution; weak electrolytes c. dissolution; ions d. precipitation; coordinate covalent bonds e. dissolution; coordinate covalent bonds
Whitten 10e
Test Bank
744
ANS: E OBJ: Complete the description of dissolution by complexation. TOP: Dissolving Precipitates 84. What is the molar solubility of AgCl in 0.10 M NH3 at 25C? Ksp is 1.8 1010 for AgCl and Kd for [Ag(NH3)2+] is 5.9 108. a. 4.98 103 M b. 3.06 103 M c. 9.44 104 d. 5.53 103 M e. 1.34 105 M ANS: A DIF: Harder Question OBJ: Calculate the molar solubility of a sparingly soluble compound in a solution of complexing agent. TOP: Dissolving Precipitates 85. Calculate the concentration of Cu2+ ions in a 0.010 M [Cu(NH3)4]2+ solution at 25C. Kd for [Cu(NH3)4]2+ = 8.5 1013 a. 1.3 103 M b. 5.1 104 M c. 6.3 105 M d. 8.7 105 M e. 1.3 106 M ANS: B OBJ: Calculate the concentration of uncomplexed metal ion. TOP: Dissolving Precipitates 86. Calculate the [Zn2+] in a solution which is initially 0.30 M in [Zn(CN)4]2 ions at 25C. Kd for [Zn(CN)4]2 = 1 1019. a. 4 105 M b. 6 108 M c. 5 106 M d. 1 103 M e. 3 104 M ANS: A OBJ: Calculate the concentration of uncomplexed metal ion. TOP: Dissolving Precipitates 87. Calculate the concentration of cadmium ions in a 0.10 M [Cd(CN)4]2 solution. The complex ion dissociates: [Cd(CN)4]2 Cd2+ + 4CN and its dissociation constant is 7.8 1018. a. 3.0 105 M b. 5.7 105 M c. 7.9 105 M d. 9.8 105 M e. 2.2 104 M
Whitten 10e
Test Bank
745
ANS: C OBJ: Calculate the concentration of uncomplexed metal ion. TOP: Dissolving Precipitates 88. Calculate the concentration of cyanide ions in a 0.10 M [Cd(CN)4]2 solution. The complex ion dissociates: [Cd(CN)4]2 Cd2+ + 4CN and its dissociation constant is 7.8 1018. a. 1.1 104 M b. 7.9 105 M c. 9.4 106 M d. 3.2 104 M e. 8.8 104 M ANS: D OBJ: Calculate the concentration of unbound complexing agent. TOP: Dissolving Precipitates 89. What is the solubility product expression for Co(OH)3? a. Ksp = [Co3+][3OH–] b. Ksp = 3[Co3+][OH–]3 c. Ksp = [Co3+][OH–]3 d. Ksp = [Co3+][3OH–]3 e. Ksp = [Co3+][OH–] ANS: C DIF: easy OBJ: Identify the correct Ksp expression given the compound formula. TOP: Solubility Product Constants 90. The concentration of strontium carbonate in a saturated aqueous solution at 25°C is 3.05 105 M. What is the Ksp of this sparingly soluble salt? a. 9.30 1010 b. 1.13 1013 c. 2.34 1017 d. 5.52 103 e. 3.12 102 ANS: A DIF: easy OBJ: Calculate the Ksp given molar solubility. TOP: Determination of Solubility Product Constants 91. The solubility of strontium carbonate in water at 25°C is 4.50 103 g/L. What is the Ksp of this sparingly soluble salt? a. 9.30 1010 b. 1.13 1013 c. 2.34 1017 d. 5.52 103 e. 3.12 102
Whitten 10e
Test Bank
746
ANS: A DIF: easy OBJ: Calculate the Ksp given solubility in g/L. TOP: Determination of Solubility Product Constants 92. Calculate the molar concentration of uncomplexed Cd2+(aq) in a solution that contains 0.25 mol of Cd(NH3)42+ per liter and 0.3137 M NH3 at equilibrium. Kf for Cd(NH3)42+ is 1.0 107 . a. 2.6 106 M b. 8.0 108 M c. 3.9 105 M d. 2.5 107 M e. 2.6 108 M ANS: A DIF: easy OBJ: Calculate the concentration of uncomplexed metal ion. TOP: Dissolving Precipitates 93. Given the two equilibria below, Ag+(aq) + 2NH3(aq); Kd = 5.9 10–8
Ag(NH3)2+(aq) AgBr(s)
Ag+(aq) + Br(aq); Ksp = 5.0 1013
what is Kc for the following equilibrium? AgBr(s) + 2NH3(aq) a. b. c. d. e.
Ag(NH3)2+(aq) + Br–(aq)
8.5 106 2.9 1020 1.2 105 7.2 1011 5.9 108
ANS: A DIF: easy OBJ: Determine K for the specified overall reaction by summing two equilibria. TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds 94. A 4.0 10–4 M solution of MnSO4 is gradually made more basic by adding NaOH. At what pH will manganese(II) hydroxide begin to precipitate? For Mn(OH)2, Ksp = 2.0 10–13. a. 4.70 b. 9.57 c. 4.65 d. 9.35 e. 9.30 ANS: D DIF: easy OBJ: Calculate the pH at which the metal hydroxide will precipitate. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
747
95. What is the minimum concentration of Ni2+ required to begin precipitating Ni(OH)2(s) in a solution of pH 10.20? For Ni(OH)2, Ksp = 2.0 10–15. a. 7.9 10–5 M b. 3.2 10–5 M c. 1.3 10–11 M d. 8.0 10–8 M e. 1.9 10–17 M ANS: D DIF: moderate OBJ: Calculate the maximum metal ion concentration possible given the solution pH. TOP: Uses of Solubility Product Constants 96. What is the pH of a saturated solution of Fe(OH)2? For Fe(OH)2, Ksp = 8.0 10–16. a. 4.93 b. 8.77 c. 5.23 d. 9.07 e. 7.00 ANS: D DIF: moderate OBJ: Calculate the pH of a saturated solution given the Ksp. TOP: Uses of Solubility Product Constants 97. The hydroxide ion concentration of a saturated solution of Cu(OH)2 is 4.58 107 M. What is the solubility product constant for Cu(OH)2? a. 4.80 1020 b. 3.84 1019 c. 9.60 1020 d. 6.77 104 e. 7.71 103 ANS: A DIF: moderate OBJ: Calculate a Ksp of a metal hydroxide given the equilibrium concentration of hydroxide ion. TOP: Uses of Solubility Product Constants 98. It is found that the concentration of Pb2+ in a saturated solution of lead(II) bromide is 1.2 10–2 M. What is Ksp for PbBr2? a. 1.7 10–6 b. 6.6 10–6 c. 1.4 10–4 d. 3.5 10–2 e. 3.1 10–7 ANS: B DIF: moderate OBJ: Calculate the Ksp of compound given the equilibrium concentration of the metal ion. TOP: Uses of Solubility Product Constants
Whitten 10e
Test Bank
748
99. The molar solubility of manganese(II) hydroxide, Mn(OH)2, is 2.26 x 10-5 M. The solubility
product constant, Ksp, for manganese(II) hydroxide is: a. 4.6 x 10-14 b. 2.3 x 10-14 c. 5.1 x 10-10 d. 2.0 x 10-9
e. 4.5 x 10-11
ANS: A OBJ: Calculate the Ksp given the molar solubility. TOP: Determination of Solubility Product Constants 100. If the molar solubility of manganese(II) hydroxide, Mn(OH)2 is 2.26 x 10-5 M, what is the pH
of a saturated solution of manganese(II) hydroxide? a. 11.978 b. 11.677 c. 10.479 d. 9.655
e. 9.354
ANS: D OBJ: Calculate the pH of a saturated solution given the Ksp. TOP: Uses of Solubility Product Constants 101. A student measures the molar solubility of iron(II) carbonate, FeCO3, in a water solution to be
6.06 x 10-6 M. Based on her data, the solubility product constant for this compound is: a. 1.21 x 10-5 b. 3.67 x 10-11 c. 8.90 x 10-27 d. 8.17 x 10-27 e. 1.06 x 10-25 ANS: B OBJ: Calculate the Ksp given the molar solubility. TOP: Determination of Solubility Product Constants
102. When 12.0 mL of a 7.13 x 10-4 M manganese(II) iodide, MnI2, solution is combined with
22.0 mL of 5.17 x 10-4 M potassium hydroxide, does a precipitate form? (Ksp for manganese(II) hydroxide is 4.6 x 10-14) a. Mn(OH)2 will precipitate until the solution is saturated b. The solution is unsaturated – no precipitate forms c. The concentration of iodide ions is reduced by the addition of OH- ions d. One must know Ksp for MnI2 to make a prediction e. The presence of KOH will raise the solubility of MnI2 ANS: A OBJ: Use a reaction quotient to determine if a precipitate forms. TOP: Reaction Quotients
103. Which of the following is the correct equilibrium expression for the solubility of magnesium
fluoride, MgF2? a. [Mg2+][F-]2 b. [Mg2+][F2-] c. [Mg+][F2-] d. e.
ANS: A OBJ: Identify the correct equilibrium expression. TOP: Equilibrium Expression
Whitten 10e
Test Bank
749
104. The molar solubility of lead(II) chloride (PbCl2) is 1.6 x 10-2 M. What is the solubility
product constant, Ksp, of PbCl2? a. 4.9 x 10-2 b. 1.7 x 10-5
c. 8.5 x 10-6
d. 4.2 x 10-6
e. 6.9 x 10-6
ANS: B OBJ: Calculate the Ksp given the molar solubility. TOP: Determination of Solubility Product Constants 105. The solubility product constant, Ksp, for ZnCO3 is 1.5 x 10-11 at 25oC and it is 3.47 x 10-11 at
45oC. Is the dissolution of ZnCO3 an endothermic or exothermic process? a. endothermic c. not enough information to tell b. exothermic ANS: A OBJ: Determine if K is exo- or endothermic given K at two temperatures. TOP: Relationship between Temperature and K
106. The molar solubility for copper(II) sulfide in water is 8.53 x 10-19M. What is the Ksp? a. 7.28 x 10-37 b. 2.48 x 10-54 c. 6.21 x 10-55 d. 1.63 x 10-89 e. 4.52 x 10-91 ANS: A OBJ: Calculate the Ksp given the molar solubility. TOP: Determination of Solubility Product Constants -4
107. Calculate Q, the reaction quotient, for when 12.0mL of 4.38 x 10 M Ba(C2H3O2)2 is mixed -5
with 25.0mL of 2.67 x 10 M Na3PO4, and predict whether a precipitate will form. Ksp for Ba3(PO4)2 is 3.40 x 10-23 a. Q = 3.16 x 10-10 and a precipitate will form b. Q = 1.75 x 10-24 and a precipitate will form c. Q = 3.16 x 10-10 and no precipitate will form d. Q = 1.75 x 10-24 and no precipitate will form e. Q = 3.40 x 10-23 and it is exactly at equilibrium ANS: D OBJ: Use a reaction quotient to determine if a precipitate forms. TOP: Reaction Quotients CONCEPTUAL 1. Why is it not correct to call silver chloride an insoluble compound? OBJ: Contrast sparingly soluble with insoluble. TOP: Solubility Product Constants 2. On the basis of Le Chatelier's Principle, explain the following observation: addition of ammonium chloride to a beaker containing solid lead hydroxide in water causes the solid to dissolve. OBJ: Explain the how a weak acid might cause the dissolution of a metal hydroxide. TOP: Dissolving Precipitates 3. Why is the concentration of solid left out of the solubility product expression? OBJ: Explain the omission of solids from equilibrium expressions. TOP: Solubility Product Constants
Whitten 10e
Test Bank
750
4. Addition of HCl and HNO3 both dissolve MnS when added to a saturated aqueous solution. Explain how each helps the dissolution process. Include equations. OBJ: Explain the how a strong acid might cause the dissolution of a basic salt. TOP: Dissolving Precipitates 5. Barium ions have an approximate LD50 of 80 mg/kg of body mass. Calculate the quantity of barium required to be lethal for a 100 kg man, then calculate the free barium ions contained in a 500 ml, saturated BaSO4 solution dose. From these calculations explain why BaSO4 can be taken orally for intestinal X-rays with no adverse effect. OBJ: Calculate the amount of barium dissolved is a solution saturated with barium sulfate, compare this to a lethal dose, and explain why barium sulfate can be taken orally. TOP: Uses of Solubility Product Constants 6. Metal parts before they are painted are often treated with acid to etch the surface of the metal to improve the adhesion of the paint. Once the acid bath becomes too concentrated in metal ions, it no longer is effective and has to be disposed of. Suppose you are now in charge of properly disposing of this waste. The last person in charge was fired for paying $100/gallon to have a hazardous waste handler haul it away because it was corrosive and contained Fe(II), Cr(III) ions in high concentration. What are some of the methods you could use to "keep your job" and impress your boss? OBJ: Apply your knowledge of equilibria in the remediation of waste metal etching solution. TOP: Fractional Precipitation 7. A suspension of magnesium hydroxide is commonly used as an antacid ingredient in "Milk of Magnesia". Why would it not be a good idea to substitute Ca(OH)2 for the same purpose? OBJ: Compare the solubilities of magnesium and calcium hydroxides. TOP: Solubility Product Constants
Chapter 21—Electrochemistry MULTIPLE CHOICE 1. Which of the following statements about electrical conduction is false? a. Both metallic and electrolytic conduction occur in electrolytic cells. b. Ionic conduction is the conduction of electric current by the motion of ions through a solution. c. Metallic conduction involves chemical change in the metal atoms. d. Electric current represents transfer of charge. e. Charge can be conducted through pure liquid electrolytes (molten salts). ANS: C OBJ: Identify the incorrect description of electrical conduction. TOP: Electrical Conduction 2. In any electrochemical cell, the cathode is always ____ a. the positive electrode. b. the negative electrode. c. the electrode at which some species gains electrons. d. the electrode at which some species loses electrons. e. the electrode at which oxidation occurs. Whitten 10e
Test Bank
751
ANS: C OBJ: Define cathode. TOP: Electrodes 3. In any electrochemical cell, the anode is always ____ a. the positive electrode. b. the negative electrode. c. the electrode at which some species gains electrons. d. the electrode at which some species loses electrons. e. the electrode at which reduction occurs. ANS: D OBJ: Define anode. TOP: Electrodes 4. In an electrolytic cell, the electrode that acts as a source of electrons to the solution is called the ____; the chemical change that occurs at this electrode is called ____. a. anode; oxidation b. anode; reduction c. cathode; oxidation d. cathode; reduction e. Cannot answer unless we know the species being oxidized and reduced. ANS: D OBJ: Complete the description of an electrolytic cell. TOP: Electrodes
Whitten 10e
Test Bank
752
5. Which of the following statements about electrodes is false? a. The cathode is the electrode at which reduction occurs. b. The anode can be either positive or negative. c. Electrodes are surfaces on which oxidation or reduction half-reactions occur. d. Electrodes that do not react are called inert electrodes. e. Electrons are gained by some species at the anode. ANS: E OBJ: Identify the incorrect description of electrodes. TOP: Electrodes 6. What product is formed at the anode when molten sodium chloride, NaCl, is electrolyzed using a Downs Cell? a. O2 b. Cl2 c. NaOH d. H2 e. Na metal ANS: B OBJ: Identify the product formed at the anode of a Downs Cell. TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell) 7. Which of the following statements concerning use of the Downs Cell for the electrolysis of molten sodium chloride is incorrect? a. The pale green gas, Cl2, is liberated at the anode. b. The anode is the positive electrode and the cathode is the negative electrode for this cell. c. The molten sodium and gaseous chlorine products must be kept separated to prevent an explosive reaction. d. The Downs cell is expensive to run because of the cost of construction, of electricity and of heat to melt the NaCl. e. Although production of sodium metal by the electrolysis of aqueous NaCl is much cheaper, the electrolysis of molten NaCl is used because it gives a purer metal. ANS: E OBJ: Identify the incorrect description of a Downs Cell. TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell) 8. Which of the following statements about what occurs during the electrolysis of molten sodium chloride is false? a. Sodium is reduced at the cathode. b. The net result is the electrolysis of water. c. Chloride is oxidized at the anode. d. Hydrogen gas and sodium hydroxide are produced at the cathode. e. Sodium is a spectator ion. ANS: B OBJ: Identify the incorrect description of a Downs Cell. TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell)
Whitten 10e
Test Bank
753
9. During the electrolysis of molten sodium bromide, sodium ions move ____. a. to the anode, which is positively charged b. to the anode, which is negatively charged c. to the cathode, which is positively charged d. to the cathode, which is negatively charged e. through the wire to the battery ANS: D OBJ: Identify the charge and identity of the electrode which attracts sodium ions in the electrolysis of molten salts. TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell) 10. The half-reaction that occurs at the cathode during the electrolysis of molten sodium bromide is ____. a. 2Br Br2 + 2e b. Br2 + 2e 2Br c. Na+ + e Na d. Na Na+ + e e. 2H2O + 2e 2OH + H2 ANS: C OBJ: Identify the cathode half-reaction in molten salt electrolysis. TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell) 11. The half-reaction that occurs at the anode during the electrolysis of molten sodium bromide is ____. a. 2Br Br2 + 2e b. Br2 + 2e 2Br c. Na+ + e Na d. Na Na+ + e e. 2H2O + 2e 2OH + H2 ANS: A OBJ: Identify the anode half-reaction in molten salt electrolysis. TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell) 12. Which of the following statements about the electrolysis of aqueous NaCl is false? a. Molten sodium metal is produced at the cathode. b. Reduction takes place at the cathode. c. Cl2 gas is produced at the anode. d. The anode is positive. e. H2O has a greater tendency to be reduced than Na+. ANS: A OBJ: Identify the incorrect description of aqueous NaCl electrolysis. TOP: The Electrolysis of Aqueous Salt Solutions 13. Which one of the following is not obtained from the electrolysis of an aqueous solution of NaCl? a. Na b. NaOH c. Cl2 d. H2 e. All of these are obtained from this electrolysis. ANS: A OBJ: Identify the compound that is not a product of aqueous NaCl electrolysis. TOP: The Electrolysis of Aqueous Salt Solutions Whitten 10e
Test Bank
754
14. The electrolysis of an aqueous sodium chloride solution using inert electrodes produces gaseous chlorine at one electrode. At the other electrode gaseous hydrogen is produced, and the solution becomes basic around the electrode. Which of the following is the equation for the cathode halfreaction in this electrolytic cell? a. 2Cl Cl2 + 2e b. 2H2O + 2e H2 + 2OH c. Cl2 + 2e 2Cl d. H2 + 2OH 2H2O + 2e e. none of these ANS: B OBJ: Identify the anode half-reaction in an aqueous NaCl electrolysis. TOP: The Electrolysis of Aqueous Salt Solutions 15. What reaction occurs at the anode during the electrolysis of aqueous Na2SO4? a. Na+ + e Na b. 2H+ + 2e H2 c. SO42 SO4 + 2e d. SO42 SO2 + O2 + 2e e. 2H2O O2 + 4H+ + 4e ANS: E OBJ: Identify the anode half-reaction in an aqueous sodium sulfate electrolysis. TOP: The Electrolysis of Aqueous Sodium Sulfate 16. Which of the following statements about the electrolysis of aqueous Na2SO4 is false? a. The cathode is negative. b. Sulfate ion is oxidized at the anode. c. Water is reduced at the cathode. d. The reaction at the anode produces e. e. H2 gas is produced at the cathode. ANS: B OBJ: Identify the incorrect description of aqueous sodium sulfate electrolysis. TOP: The Electrolysis of Aqueous Sodium Sulfate 17. For the electrolysis of aqueous KCl solution using inert electrodes, chlorine gas is evolved at one electrode and hydrogen gas is evolved at the other electrode. The solution around the electrode at which hydrogen gas is evolved becomes basic as the electrolysis proceeds. Which reaction occurs at the anode? a. 2Cl Cl2 + 2e b. 2H2O O2 + 4H+ + 4e c. Cl2 + 2e 2Cl d. 2H2O + 2e H2 + 2OH e. None of these is correct. ANS: A OBJ: Identify the anode half-reaction in an aqueous KCl electrolysis. TOP: The Electrolysis of Aqueous Sodium Sulfate
Whitten 10e
Test Bank
755
18. Which of the following statements regarding Faraday's Law of Electrolysis is false? a. The faraday is a quantitative unit of electricity. b. One mole of electrons gained in reduction is equivalent to one faraday of electricity. c. One mole of electrons lost in oxidation is equivalent to one faraday of electricity. d. One coulomb = 96,485 faradays. e. One ampere of current = One coulomb per second. ANS: D OBJ: Identify the incorrect description of Faraday's law of electrolysis. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 19. How many coulombs of charge pass through a cell if 2.40 amperes of current are passed through the cell for 85.0 minutes? a. 2.04 102 C b. 1.33 101 C c. 1.22 104 C d. 2.12 103 C e. 3.40 C ANS: C OBJ: Calculate the coulombs of charge passed given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 20. How many faradays (F) are passed through a cell if 6.25 amperes of current are passed through the cell for 1.50 hours? a. 4.19 F b. 2.86 F c. 251 F d. 0.350 F e. 5.83 103 F ANS: D OBJ: Calculate the number of faradays passed given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 21. An aqueous copper(II) sulfate solution is electrolyzed for 45 minutes. A 3.2 ampere current is used. What mass of copper is produced? a. 0.95 g b. 1.9 g c. 2.8 g d. 4.6 g e. 5.5 g ANS: C OBJ: Calculate the mass of metal produced given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 22. How many moles of oxygen, O2, will be produced by the electrolysis of water with a current of 1.5 amperes for 6.0 hours? a. 0.014 mol b. 0.34 mol c. 0.74 mol d. 0.084 mol e. 0.0014 mol
Whitten 10e
Test Bank
756
ANS: D OBJ: Calculate the moles of oxygen produced in aqueous electrolysis given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 23. How many grams of metallic nickel can be produced by the electrolysis of aqueous nickel(II) chloride, NiCl2, with a 0.350 ampere current for 5.00 hours? a. 1.19 g b. 1.92 g c. 7.66 g d. 2.76 g e. 3.83 g ANS: B OBJ: Calculate the mass of metal produced given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 24. An aqueous solution of nickel acetate is electrolyzed for 3 hours with a 1.8 ampere current. What mass of nickel is produced? a. 3.28 g b. 5.91 g c. 11.8 g d. 7.30 g e. 0.099g ANS: B OBJ: Calculate the mass of metal produced given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 25. How many liters of F2 at STP could be liberated from the electrolysis of molten NaF under a 2.16 ampere current for 60.0 minutes? a. 0.774 L b. 0.902 L c. 1.55 L d. 1.80 L e. 2.16 L ANS: B OBJ: Calculate the liters of gaseous fluorine produced in molten electrolysis given current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 26. Calculate the quantity of charge necessary to produce 10 liters of H2(g) at STP from the electrolysis of water. a. 8.6 104 coulombs b. 3.7 104 coulombs c. 1.7 104 coulombs d. 5.3 104 coulombs e. 4.8 104 coulombs ANS: A OBJ: Calculate the coulombs of charge required for the production of an amount of gas by electrolysis. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis
Whitten 10e
Test Bank
757
27. How long would a constant current of 18.0 amperes be required to flow in order for 9000. coulombs of charge to pass through a cell? a. 200. s b. 500. s c. 0.002 s d. 50. s e. 1.6 105 s ANS: B OBJ: Calculate the time required to pass a certain amount of charge given current. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 28. For how many minutes would 8.55 A of current need to flow to produce 3.17 104 C? a. 3710 minutes b. 528 minutes c. 4520 minutes d. 2.81 minutes e. 61.8 minutes ANS: E OBJ: Calculate the time required to pass a certain amount of charge given current. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 29. Current is passed through a cell where the half-reaction that occurs at the cathode is 5e + MnO4 + 8H+ Mn2+ + 4H2O All the MnO4 ions present in 25.0 mL of solution have been reduced after a current of 0.600 ampere has passed for 844 seconds. What was the original concentration of MnO4 ions? a. 7.10 103 M b. 1.02 101 M c. 0.21 M d. 1.47 M e. 4.20 102 M ANS: E DIF: Harder Question OBJ: Calculate the concentration of a species given the current and time required to achieve complete reduction. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 30. How many moles of chromium would be electroplated by passing a current of 5.2 amperes through a solution of Cr2(SO4)3 for 45.0 minutes? a. 0.048 mol b. 2.9 mol c. 0.15 mol d. 6.9 mol e. 0.073 mol ANS: A OBJ: Calculate the moles of metal produced given current and time. TOP: Commercial Applications of Electrolytic Cells
Whitten 10e
Test Bank
758
31. How long would a constant current of 4.5 amperes be required to flow in order to plate out 15 g of chromium from a chromium(III) sulfate solution? a. 268 hr b. 309 hr c. 5.15 hr d. 23.2 hr e. 1.72 hr ANS: C OBJ: Calculate the time required to produce a certain amount of metal at a given current. TOP: Commercial Applications of Electrolytic Cells 32. Molten AlCl3 is electrolyzed for 5.0 hours with a current of 0.40 ampere. Metallic aluminum is produced at one electrode and chlorine gas, Cl2, is produced at the other. How many grams of aluminum are produced? a. 1.1 g b. 0.22 g c. 0.44 g d. 0.58 g e. 0.67 g ANS: E OBJ: Calculate the mass of metal produced given current and time. TOP: Commercial Applications of Electrolytic Cells 33. Molten AlCl3 is electrolyzed for 5.0 hours with a current of 0.40 ampere. Metallic aluminum is produced at one electrode and chlorine gas, Cl2, is produced at the other. How many liters of Cl2 measured at STP are produced at the other electrode? a. 0.56 L b. 0.63 L c. 0.84 L d. 0.98 L e. 1.02 L ANS: C OBJ: Calculate the liters of gaseous chlorine produced in molten electrolysis given current and time. TOP: Commercial Applications of Electrolytic Cells 34. How many mL of chlorine gas can be obtained at STP by the electrolysis of molten NaCl using a 0.500 ampere current for 25.0 minutes? a. 87.0 mL b. 48.7 mL c. 348 mL d. 174 mL e. 3.89 mL ANS: A OBJ: Calculate the volume of gaseous chlorine produced in molten electrolysis given current and time. TOP: Commercial Applications of Electrolytic Cells
Whitten 10e
Test Bank
759
35. How many minutes would a 5.00 ampere current have to be applied to plate out 8.00 grams of copper metal from aqueous copper(II) sulfate solution? a. 14.6 minutes b. 33.3 minutes c. 81.0 minutes d. 124 minutes e. 188 minutes ANS: C OBJ: Calculate the time required to produce a certain amount of metal at a given current. TOP: Commercial Applications of Electrolytic Cells 36. A spoon is to be electroplated with gold using 1.0 M Au(NO3)3 and 2.57 A of current. How many minutes are required to deposit 5.50 grams of gold on the spoon? a. 17.5 minutes b. 52.4 minutes c. 3145 minutes d. 135 minutes e. 0.266 minutes ANS: B OBJ: Calculate the time required to produce a certain amount of metal at a given current. TOP: Commercial Applications of Electrolytic Cells 37. Molten AlCl3 is electrolyzed with a current of 0.500 ampere. Metallic aluminum is produced at one electrode and chlorine gas, Cl2, is produced at the other. If 0.450 liters of Cl2, measured at STP, are produced at one electrode, how many grams of aluminum are produced at the other? a. 0.362 g b. 0.373 g c. 0.542 g d. 0.181 g e. 0.893 g ANS: A DIF: Harder Question OBJ: Calculate the mass of a product generated at one electrode given the volume of product generated at the other electrode. TOP: Commercial Applications of Electrolytic Cells 38. Which of the following statements about voltaic cells is false? a. Voltaic cells are spontaneous reactions. b. The cathode is positive. c. Electrons flow from the cathode to the anode. d. A salt bridge maintains electrical contact and charge neutrality in the half-cells. e. The half-reactions take place in separate cells. ANS: C OBJ: Identify the incorrect description of a voltaic cell. TOP: The Construction of Simple Voltaic Cells
Whitten 10e
Test Bank
760
39. In voltaic cells, such as those diagrammed in your text, the salt bridge ____. a. is not necessary in order for the cell to work b. acts as a mechanism to allow mechanical mixing of the solutions c. allows charge balance to be maintained in the cell d. is tightly plugged with a firm agar gel through which ions cannot move e. drives electrons from one half-cell to the other ANS: C OBJ: Identify the purpose of a salt bridge. TOP: The Construction of Simple Voltaic Cells 40. Reduction occurs at the ____ in a voltaic cell and reduction occurs at the ____ in an electrolytic cell. a. anode; anode b. cathode; cathode c. anode; cathode d. cathode; anode e. anode; salt bridge ANS: B OBJ: Identify the electrode where reduction occurs in an electrolytic or voltaic cell. TOP: The Construction of Simple Voltaic Cells 41. Which of the following statements about the salt bridge in a voltaic cell is false? a. It allows electrical contact between the two solutions in the half-cells. b. The ions from the salt bridge participate in the half-reactions. c. It prevents mixing of the electrode solutions. d. It maintains the electrical neutrality in each half-cell. e. Ions flow into and out of the salt bridge. ANS: B OBJ: Identify the incorrect description of a salt bridge. TOP: The Construction of Simple Voltaic Cells 42. A voltaic cell is constructed with one cell consisting of an Al electrode in 1.0 M Al3+ and another cell with an Fe electrode in 1.0 M Fe2+. When this cell operates, the Al electrode loses mass and the Fe electrode gains mass. Which of the following represents the reaction that occurs at the positive electrode of this cell? a. Al3+ + 3e Al b. Fe Fe2+ + 2e c. Al Al3+ + 3e d. Fe2+ + 2e Fe e. Fe2+ Fe3+ + e ANS: D OBJ: Identify the half reaction that occurs at the positive electrode. TOP: The Construction of Simple Voltaic Cells 43. A voltaic cell is constructed with one cell consisting of an Cd electrode in 1.0 M Cd2+ and another cell with an Sn electrode in 1.0 M Sn2+. When this cell operates, the Cd electrode loses mass and the Sn electrode gains mass. Which of the following represents the reaction that occurs at the negative electrode of this cell?
Whitten 10e
Test Bank
761
a. b. c. d. e.
Cd2+ + 2e Cd Sn Sn2+ + 2e Cd Cd2+ + 2e Sn2+ Sn4+ + 2e Sn2+ + 2e Sn
ANS: C OBJ: Identify the half reaction that occurs at the positive electrode. TOP: The Construction of Simple Voltaic Cells Chapter 21 Values A table of standard electrode potentials is necessary for many of the following question(s). 44. Which of the following statements about the operation of a standard galvanic cell made of a Cu/Cu2+ half-cell and a Zn/Zn2+ half-cell is false? a. The mass of the copper electrode increases. b. The [Zn2+] increases. c. The [Cu2+] decreases. d. The salt bridge maintains charge neutrality. e. The zinc electrode is reduced. ANS: E OBJ: Identify the incorrect description of a galvanic cell. TOP: The Zinc – Copper Cell 45. Which of the following shorthand galvanic cell notations for the zinc copper standard cell is correct? Cu2+ + Zn Zn2+ + Cu a. b. c. d. e.
Cu2+ | Cu || Zn | Zn2+ Cu2+ | Cu || Cu | Cu2+ Cu2+ | 2e || 2e | Zn Zn | Zn2+ || Cu2+ | Cu Zn | Cu2+ || Zn2+ | Cu
ANS: D OBJ: Identify the correct cell notation for a reaction. TOP: The Zinc – Copper Cell 46. Which of the following statements about the operation of a standard galvanic cell made of a Cu/Cu2+ half-cell and a Ag/Ag+ half-cell is false? a. The mass of the copper electrode decreases. b. The electrons flow from the copper electrode to the silver electrode. c. The [Cu2+] increases. d. Positive ions enter into the Ag/Ag+ half-cell from the salt bridge. e. The copper electrode is positive. ANS: E OBJ: Identify the incorrect description of a galvanic cell. TOP: The Copper – Silver Cell
Whitten 10e
Test Bank
762
47. Which of the following statements about the standard hydrogen electrode (SHE) is incorrect? a. The potential is arbitrarily assigned a value of 0.000 V. b. The reduction half-reaction is 2H+ + 2e H2 c. The oxidation half-reaction is H2 + 2e 2H+ d. The cell consists of 1.0 atm H2 gas, 1.0 M HCl and a Pt electrode. e. The Pt electrode is inert. ANS: C OBJ: Identify the incorrect description of the SHE. TOP: The Standard Hydrogen Electrode 48. When the SHE is combined with a standard Zn/Zn2+ half-cell, which of the following represents the correct overall reaction and cell potential? a. Zn + 2H+ Zn2+ + H2; E0cell = 0.000 V b. Zn + 2H+ Zn2+ + H2; E0cell = 0.763 V c. Zn + 2H+ Zn2+ + H2; E0cell = 0.763 V d. Zn2+ + H2 Zn + 2H+; E0cell = 0.763 V e. Zn2+ + H2 Zn + 2H+; E0cell = 0.763 V ANS: B OBJ: Determine the cell potential and overall reaction of an electrochemical cell. TOP: The Zinc – SHE Cell 49. When the SHE is combined with a standard Cu/Cu2+ half-cell, which of the following statements is false? a. The copper (II) ion is reduced. b. H2 is oxidized. c. The observed cell potential represents the reduction potential for Cu2+. d. The oxidation potential is 0.337 V. e. Current flows from the SHE to the Cu/Cu2+. ANS: D OBJ: Determine the cell potential and overall reaction of an electrochemical cell. TOP: The Copper – SHE Cell 50. The observed cell potential of a voltaic cell consisting of one SHE and the standard Cu/Cu2+ half-cell is 0.337 V. Hydrogen is oxidized in this cell. Which of the following statements is true? a. The reduction potential of the cathode is 0.00 V. b. The reduction potential of Cu2+ is 0.337 V. c. The oxidation potential of the anode is 0.337 V. d. The reduction potential of Cu2+ is 0.337 V. e. The oxidation potential of H2 is 0.337 V. ANS: B OBJ: Identify the correct description of an electrochemical cell. TOP: The Copper – SHE Cell 51. Which statement concerning a table of standard reduction potentials is incorrect? a. On the left side of the table are cations, hydrogen ion and elemental nonmetals. b. On the right side of the table are elemental metals, hydrogen and nonmetal anions. c. Fluorine, F2, is the strongest oxidizing agent. d. The alkali metals (Group IA) are among the strongest reducing agents. e. The more positive the reduction potential, the stronger the species on the left acts as a reducing agent. Whitten 10e
Test Bank
763
ANS: E OBJ: Identify the incorrect description of standard reduction potentials. TOP: Standard Electrode Potentials 52. Which of the following is the strongest oxidizing agent? a. Mg2+ b. Mg c. F2 d. F e. H+ ANS: C OBJ: Identify the strongest oxidant. TOP: Standard Electrode Potentials 53. Which of the following species is the strongest oxidizing agent? a. Sn2+ b. Sn4+ c. Br2 d. Br e. Li ANS: C OBJ: Identify the strongest oxidant. TOP: Standard Electrode Potentials 54. Which of the following species is the strongest reducing agent? a. Mn2+ b. Mn c. Au+ d. H2 e. Au ANS: B OBJ: Identify the strongest reductant. TOP: Standard Electrode Potentials 55. Which of the following is the strongest reducing agent? a. K b. Ag c. Ba2+ d. F2 e. Cu ANS: A OBJ: Identify the strongest reductant. TOP: Standard Electrode Potentials 56. Which of the following is the weakest reducing agent? a. Al3+ b. Al c. F2 d. F e. K+
Whitten 10e
Test Bank
764
ANS: D OBJ: Identify the weakest reductant. TOP: Standard Electrode Potentials 57. Which of the following is the weakest oxidizing agent? a. Cu2+ b. Zn2+ c. F d. Na e. K+ ANS: E OBJ: Identify the weakest oxidant. TOP: Standard Electrode Potentials 58. Which of the following metals is most easily oxidized? a. Cd b. Cu c. Fe d. Sn e. Zn ANS: E OBJ: Identify the species that is easiest to oxidize. TOP: Standard Electrode Potentials 59. Which one of the following statements about the oxidizing strength of the group IB metals (Cu, Ag, and Au) is true? a. Cu is easier to oxidize than Au. b. Au is easier to oxidize than Ag. c. Ag is easier to oxidize than Cu. d. Au is easier to oxidize than Cu. e. Nothing can be decided about this from a table of electrode potentials. ANS: A OBJ: Identify the correct description of relative oxidizing strength. TOP: Standard Electrode Potentials 60. At standard conditions, which of the following can oxidize Hg to Hg2+? a. Cu2+ b. Cl2 c. Ag d. Zn2+ e. Zn ANS: B OBJ: Identify the species capable of performing a given oxidation. TOP: Standard Electrode Potentials
Whitten 10e
Test Bank
765
61. At standard conditions, which one of the following will reduce Ni2+ to Ni but will not reduce Mg2+ to Mg? a. Cd2+ b. Sn c. Ca d. Cr e. Na ANS: D OBJ: Identify the species capable of reducing one species but not another. TOP: Standard Electrode Potentials 62. Which one of the following statements about the half-cell processes is true for the cell, Cd|Cd2+(1 M)||Cu2+(1 M)|Cu? a. Cu2+ is reduced at the anode. b. Cu2+ is reduced at the cathode. c. Cd2+ is reduced at the anode. d. Cd2+ is reduced at the cathode. e. The spontaneous reaction that occurs in this cell is not a redox reaction. ANS: B OBJ: Identify the correct description of an electrochemical cell. TOP: Uses of Standard Electrode Potentials 63. A voltaic cell consists of a standard hydrogen electrode connected by a salt bridge and a wire to an electrode consisting of a strip of Cd metal dipping into a 1 M solution of Cd(NO3)2. When the cell produces current, the electrons flow through the wire from the ____ electrode to the ____ electrode. In this cell the ____ electrode acts as the cathode. a. Cd; H2; Cd b. H2; Cd; Cd c. H2; Cd; H2 d. Cd; H2; H2 e. None of these is correct. ANS: D OBJ: Identify the direction of electron flow and the cathode identity in an electrochemical cell. TOP: Uses of Standard Electrode Potentials 64. The following are metal pairs representing electrodes in theoretical voltaic cells. Which pair is incorrectly labeled? a. Ag, oxidized / Cu, reduced b. Ag, oxidized / Au, reduced c. Ni, reduced / Al, oxidized d. Cu, reduced / Pb, oxidized e. Na, oxidized / Mg, reduced ANS: A OBJ: Identify the electrode pair that is incorrectly labeled. TOP: Uses of Standard Electrode Potentials 65. Which of the following describes the net reaction that occurs in the cell, Cd|Cd2+(1 M)||Cu2+(1 M)|Cu? a. Cu + Cd2+ Cu2+ + Cd b. Cu + Cd Cu2+ + Cd2+ c. Cu2+ + Cd2+ Cu + Cd d. Cu2+ + Cd Cu + Cd2+ Whitten 10e
Test Bank
766
e. 2Cu + Cd2+ 2Cu+ + Cd ANS: D OBJ: Identify the net reaction represented by an electrochemical cell. TOP: Uses of Standard Electrode Potentials 66. Which one of the following reactions is spontaneous (in the direction given) under standard electrochemical conditions? a. Pb2+ + 2I Pb + I2 b. Cu2+ + Fe Cu + Fe2+ c. 2Au + Pt2+ 2Au+ + Pt d. Mg2+ + 2Br Mg + Br2 e. 2Hg + 2Cl + 2H+ Hg2Cl2 + H2 ANS: B OBJ: Identify the reaction that is spontaneous as written. TOP: Uses of Standard Electrode Potentials 67. What is the cell potential for a cell constructed by immersing a strip of manganese in a 1.0 M MnSO4 solution and a strip of iron in a 1.0 M FeSO4 solution and completing the circuit by a wire and a salt bridge? a. 1.62 V b. +1.62 V c. 0.74 V d. +0.74 V e. +1.21 V ANS: D OBJ: Calculate the cell potential of an electrochemical cell. TOP: Uses of Standard Electrode Potentials 68. A voltaic cell is constructed by immersing a strip of copper metal in 1.0 M CuSO4 solution and a strip of aluminum in 0.50 M Al2(SO4)3 solution. A wire and a salt bridge complete the circuit. The aluminum strip loses mass, and the concentration of aluminum ions in the solution increases. The copper electrode gains mass, and the concentration of copper ions decreases. What is the cell potential? a. +1.28 V b. +2.00 V c. +2.34 V d. +2.50 V e. +3.66 V ANS: B OBJ: Calculate the cell potential of an electrochemical cell. TOP: Uses of Standard Electrode Potentials 69. What is the numerical value for the standard cell potential for the following reaction? 2Cr3+(aq) + 3Cu(s) 2Cr(s) + 3Cu2+(aq) a. b. c. d. e.
1.08 V 0.40 V 0.40 V 1.08 V 2.52 V
Whitten 10e
Test Bank
767
ANS: A OBJ: Calculate the cell potential of an electrochemical cell with the given net reaction. TOP: Uses of Standard Electrode Potentials 70. Calculate the standard cell potential for the cell, Cd|Cd2+(1 M)||Cu2+(1 M)|Cu. a. +0.74 V b. 0.74 V c. +0.06 V d. 0.06 V e. 0.00 V ANS: A OBJ: Calculate the cell potential of an electrochemical cell. TOP: Uses of Standard Electrode Potentials 71. Which of the following is the strongest oxidizing agent in 1 M solutions? a. MnO4 (in aqueous acidic solution) b. Ag+(aq) c. Cu2+(aq) d. Ca2+(aq) e. Li+(aq) ANS: A OBJ: Identify the strongest oxidant. TOP: Standard Electrode Potentials for Other Half-Reactions 72. A voltaic cell is constructed by immersing a strip of cobalt metal into a 1.0 M solution of Co(NO3)2 and connecting this electrode by a wire and salt bridge to a strip of platinum in contact with a solution that is 0.50 M in Fe2(SO4)3 and 1.0 M in FeSO4. Consult the table of standard electrode potentials to determine the reaction that occurs. Which of the following is the anode half-reaction? a. Fe3+ + e Fe2+ b. Co2+ + 2e Co c. 2H+ + 2e H2 d. Co Co2+ + 2e e. Fe2+ Fe3+ + e ANS: D OBJ: Identify the anode half-reaction of an electrochemical cell. TOP: Standard Electrode Potentials for Other Half-Reactions 73. Given the following standard electrode potentials: E0 +1.23 V 0.49 V
Half-Reaction O2(g) + 4H + 4e 2H2O 2CO2(g) + 2H+ + 2e (COOH)2 +
Calculate the standard cell potential for the galvanic cell consisting of these reactions. a. 0.74 V b. 0.74 V c. 1.72 V d. 2.21 V e. 1.72 V
Whitten 10e
Test Bank
768
ANS: C OBJ: Calculate the cell potential of an electrochemical cell given the half reactions. TOP: Standard Electrode Potentials for Other Half-Reactions 74. Which response includes all of the following reactions (and no others) that can be used (in the direction given) for a galvanic cell under standard electrochemical conditions? I. Sn2+ + Mg2+ Sn4+ + Mg II. Cu2+ + Fe Cu + Fe2+ III. H2O2 + Sn4+ O2 + Sn2+ + 2H+ IV. 2Hg + 2Cl + 2H+ Hg2Cl2 + H2 a. b. c. d. e.
I and II II I, III, and IV II and IV another combination
ANS: B OBJ: Identify the reactions that are spontaneous as written. TOP: Standard Electrode Potentials for Other Half-Reactions 75. Which response lists all of the following reactions that are spontaneous under standard electrochemical conditions? I. Cr(s) + 3Fe3+ 3Fe2+ + Cr3+ II. 2Fe2+ + Cu2+ 2Fe3+ + Cu III. a. b. c. d. e.
Li(s) + H+ Li+ + H2 (g) I II III II and III I and III
ANS: E OBJ: Identify the reactions that are spontaneous as written. TOP: Standard Electrode Potentials for Other Half-Reactions 76. Which one(s) of the following reactions is (are) spontaneous under standard electrochemical conditions? I. 2Al3+ + 3Cu 2Al + 3Cu2+ II. Sn2+ + H2 Sn + 2H+ III. Hg2+ + Ni Hg + Ni2+ IV. O2 + 4H+ + 2Cd 2H2O + 2Cd2+ a. b. c. d. e.
I and II III II and IV III and IV II, III, and IV
ANS: D OBJ: Identify the reactions that are spontaneous as written. TOP: Standard Electrode Potentials for Other Half-Reactions Whitten 10e
Test Bank
769
77. Considering the corrosion of ferrous (containing iron) metal, which of the following statements is false? a. Iron atoms are oxidized to iron cations. b. Water is reduced in the presence of oxygen. c. Iron is oxidized in the anode region. d. Corrosion occurs spontaneously. e. Hydroxide ions formed at the anode region combine with Fe2+ formed at the cathode region to produce rust. ANS: E OBJ: Identify the incorrect description of ferrous metal corrosion. TOP: Corrosion 78. In the corrosion of iron, pitting occurs ____ a. at the anode region. b. at the cathode region. c. because of the reduction of water. d. because of the reduction of iron. e. due to the build-up of rust. ANS: A OBJ: Identify the correct description of pitting in corrosion. TOP: Corrosion 79. Which of the following is not a method of corrosion protection? a. Submerging the metal under water. b. Plating the metal with a layer of less easily oxidized metal. c. Connecting the metal to a sacrificial anode. d. Allow a protective metal oxide film to form on the metal. e. Galvanizing the metal. ANS: A OBJ: Identify the incorrect method of corrosion protection. TOP: Corrosion Protection 80. If a copper-plated iron can is scratched, the iron beneath it corrodes more rapidly than it would without the coating. On the other hand, a galvanized iron can is not oxidized if its coating is scratched. Which statement below about these processes is false? a. Copper is less active than iron. b. Zinc is more active than iron. c. The zinc is preferentially reduced. d. Zinc is acting as a sacrificial anode. e. Copper is less easily oxidized than iron. ANS: C OBJ: Identify the incorrect description of two methods of corrosion protection. TOP: Corrosion Protection
Whitten 10e
Test Bank
770
81. Which statement concerning protecting metals against corrosion is false? a. A metal protected by a thin layer of a less easily oxidized metal will corrode even more rapidly if the layer is breached because an adverse electrochemical cell is created. b. A metal may be directly connected to a "sacrificial anode" (another metal that is more active and therefore preferentially oxidized). c. Some metals naturally form a protective film on their surface, often the metal oxide. d. Galvanizing (coating iron with the more active metal, zinc) is only protective as long as the coating layer remains intact. If the zinc coating is broken, there is no more protection. e. Nonmetal coatings such as paint may be used to prevent contact with oxygen. ANS: D OBJ: Identify the incorrect description of metal corrosion protection. TOP: Corrosion Protection 82. A zinc bar weighing 3.0 kg is attached to a buried iron pipe to protect the pipe from corrosion. An average current of 0.020 A flows between the bar and the pipe. How many years will be required for the zinc bar to be entirely consumed? (1 yr = 3.16 107 s) a. 600 yr b. 14.0 yr c. 5.99 yr d. 7.00 yr e. 6.66 yr ANS: B OBJ: Calculate the time required to consume a mass of metal given current. TOP: Corrosion Protection 83. Calculate the reduction potential of the Cu2+/Cu electrode when [Cu2+] = 1.0 108 M. a. +0.10 V b. +0.33 V c. +0.34 V d. +0.35 V e. +0.37 V ANS: A OBJ: Calculate a half-cell potential under non-standard conditions. TOP: The Nernst Equation 84. A cell is constructed by immersing a strip of silver in 0.10 M AgNO3 solution and a strip of lead in 1.0 M Pb(NO3)2 solution. A wire and salt bridge complete the cell. What is the potential of the silver electrode in the cell? a. 0.74 V b. 0.80 V c. 0.83 V d. 0.86 V e. 0.88 V ANS: A OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions. TOP: The Nernst Equation
Whitten 10e
Test Bank
771
85. A cell is constructed by immersing a strip of silver in 0.10 M AgNO3 solution and a strip of lead in 1.0 M Pb(NO3)2 solution. A wire and salt bridge complete the cell. What is the potential for the cell? a. 0.90 V b. 0.87 V c. 0.95 V d. 0.96 V e. 0.98 V ANS: B OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions. TOP: The Nernst Equation 86. Calculate Ecell for the reaction below when [Zn2+] = 1.00 M, [H+] = 1.00 106 M, and
= 1.00 atm.
Zn(s) + 2H+ Zn2+ + H2(g) a. b. c. d. e.
+0.41 V +0.053 V +0.64 V +1.12 V +0.76 V
ANS: A OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions given the net reaction. TOP: The Nernst Equation 87. What is the cell potential for the following reaction if the [Au+] = 0.0015 M and the [Fe3+] = 0.033 M? Relevant half-reactions are Fe3+(aq) + 3e Fe(s), E0red = 0.04 V and Au+(aq) + e Au(s), E0red = 1.69 V. Fe(s) + 3Au+(aq) Fe3+(aq) + 3Au(s) a. b. c. d. e.
1.87 V 1.73 V 1.65 V 1.70 V 1.59 V
ANS: E OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions given the net reaction. TOP: The Nernst Equation 88. Consider the following reaction: If a galvanic cell utilizes this reaction and the initial concentrations are [Hg22+] = 0.10 M, [Sn2+] = 0.30 M, and [Sn4+] = 0.20 M, what will be Ecell under these conditions? Hg22+(aq) + Sn2+(aq) Sn4+(aq) + 2Hg(l) a. b. c. d. e.
0.57 V 0.61 V 0.74 V 0.66 V 0.68 V
Whitten 10e
Test Bank
772
ANS: B OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions given the net reaction. TOP: The Nernst Equation 89. What is the cell potential for the reaction below if [Cr2O72] = 0.0010 M, [Cr3+] = 0.150 M, [H+] = 1.00 M, and [Br] = 0.450 M, and some bromine is also present initially? Cr2O72 + 14H+ + 6Br 3Br2 + 2Cr3+ + 7H2O a. b. c. d. e.
+0.28 V +0.31 V +0.22 V +0.24 V +0.29 V
ANS: C OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions given the net reaction. TOP: The Nernst Equation 90. Calculate the cell potential of the following voltaic cell. Zn|Zn2+(1.0 104 M)||Cu2+(1.0 106 M)|Cu a. b. c. d. e.
+0.98 V +1.10 V +1.04 V +1.22 V +1.16 V
ANS: C OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions. TOP: The Nernst Equation 91. Calculate the cell potential of the following voltaic cell at 25C. Mg|Mg2+(1.0 106 M)||Ag+(1.0 102 M)|Ag a. b. c. d. e.
+3.17 V +3.29 V +3.23 V +3.11 V +1.63 V
ANS: C OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions. TOP: The Nernst Equation 92. Calculate Ecell for the following voltaic cell at 25C. Ag|Ag+(1.0 105 M)||Au3+(1.0 101 M)|Au a. b. c. d. e.
+0.78 V +0.46 V +0.88 V +0.98 V +2.58 V
Whitten 10e
Test Bank
773
ANS: D OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions. TOP: The Nernst Equation 93. Calculate the cell potential for the following voltaic cell. Cr|Cr3+(1.0 102 M)||Co2+(1.0 105 M)|Co a. b. c. d. e.
+0.35 V +0.91 V +0.57 V +0.28 V 1.13 V
ANS: A OBJ: Calculate the cell potential of an electrochemical cell under non-standard conditions. TOP: The Nernst Equation 94. Calculate the Cd2+ concentration in the following cell if Ecell = 0.23 V. Cd(s)|Cd2+(? M)||Ni2+(1.00 M)|Ni a. b. c. d. e.
0.0019 M 1.4 105 M 0.0036 M 0.015 M 0.0086 M
ANS: A OBJ: Calculate the concentration of an electrochemical cell component given the cell potential. TOP: Using Electrochemical Cells to Determine Concentrations 95. Calculate the [H+] for the hydrogen half-cell of the following voltaic cell if the observed cell voltage is 2.02 V. Mg|Mg2+(1.00 M)||H+(? M), H2(1.00 atm)|Pt a. b. c. d. e.
8.0 105 M 1.1 103 M 9.8 101 M 8.0 103 M 1.2 106 M
ANS: E OBJ: Calculate the concentration of an electrochemical cell component given the cell potential. TOP: Using Electrochemical Cells to Determine Concentrations 96. Calculate the pH for the hydrogen half-cell of the following voltaic cell if the observed cell voltage is 1.00 V. Mn|Mn2+(1.00 M)||H+(pH =?), H2(1.00 atm)|Pt a. b. c. d. e.
3.04 4.31 1.52 3.62 2.78
Whitten 10e
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ANS: A OBJ: Calculate the pH of an electrochemical cell solution given the cell potential. TOP: Using Electrochemical Cells to Determine Concentrations 97. A concentration cell is constructed by placing identical iron electrodes in two Fe2+ solutions. The potential of this cell is observed to be 0.047 V. If the more concentrated Fe2+ solution is 0.10 M, what is the concentration of the other Fe2+ solution? a. 1.5 102 M b. 2.8 105 M c. 3.5 104 M d. 9.2 102 M e. 2.6 103 M ANS: E OBJ: Calculate the concentration of an electrochemical cell component given the cell potential. TOP: Using Electrochemical Cells to Determine Concentrations 98. Which of the following statements about a concentration cell is false? a. The concentration decreases in the more concentrated half-cell. b. Both half-cells are composed of the same species. c. E0 is always zero in a concentration cell. d. The spontaneous reaction is always from the more dilute solution to the more concentrated solution. e. The concentration increases in the less concentrated half-cell. ANS: D OBJ: Identify the incorrect description of a concentration cell. TOP: Using Electrochemical Cells to Determine Concentrations 99. What is G0 at 25C for the reaction below? (F = 96,500 J/Vmol e) Cu2+ + Cd Cu + Cd2+ a. b. c. d. e.
71.1 kJ 143 kJ 597 kJ 193 kJ +71.1 kJ
ANS: B OBJ: Calculate delta G given the net reaction. TOP: The Relationship of E°cell to Delta G° and K 100. Calculate the Gibbs free energy change for the reaction below when initial concentrations of Cr3+ and Cu2+ are 1.00 M. (F = 96,500 J/Vmol e) 2Cr3+(aq) + 3Cu(s) 2Cr(s) + 3Cu2+(aq) a. b. c. d. e.
232 kJ 623 kJ 313 kJ 232 kJ 523 kJ
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ANS: B OBJ: Calculate delta G given the net reaction. TOP: The Relationship of E°cell to Delta G° and K 101. Calculate G0 for the following reaction from its 3Hg2Cl2 + 2Cr 2Cr3+ + 6Hg + 6Cl a. b. c. d. e.
value. (F = 96,500 J/Vmol e)
1.12 103 kJ 585 kJ 361 kJ 1.62 103 kJ 1.78 103 kJ
ANS: B OBJ: Calculate delta G given the net reaction. TOP: The Relationship of E°cell to Delta G° and K 102. What is G0 per mole of dichromate ions for the reduction of dichromate ions, Cr2O72, to Cr3+ by bromide ions, Br, in acidic solution? (F = 96,500 J/Vmol e) Cr2O72 + 14H+ + 6Br 3Br2 + 2Cr3+ + 7H2O a. b. c. d. e.
+26.3 kJ 145 kJ +145 kJ 26.3 kJ 53.6 kJ
ANS: B OBJ: Calculate delta G given the net reaction. TOP: The Relationship of E°cell to Delta G° and K 103. The standard reduction potentials for the half-reactions below are 0.7994 and 0.222 volt, respectively. Ag+(aq) + e Ag(s) AgCl(s) + e Ag(s) + Cl(aq) Calculate Ksp for AgCl at 25C. (F = 96,500 J/Vmol e and R = 8.314 J/molK) a. 4.7 1012 b. 3.2 108 c. 6.2 109 d. 4.3 108 e. 1.7 1010 ANS: E OBJ: Calculate a K given the relevant standard reduction potentials. TOP: The Relationship of E°cell to Delta G° and K 104. Given the standard electrode potentials below, calculate Kc at 25C for the following reaction. (F = 96,500 J/Vmol e and R = 8.314 J/molK) 2Fe3+(aq) + 2I(aq) 2Fe2+(aq) + I2(s)
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E0 +0.771 V +0.535 V
Fe3+(aq) + e Fe2+(aq) I2(s) + 2e 2I(aq) a. b. c. d. e.
1.6 1012 1.1 108 1.0 104 9.6 107 9.7 103
ANS: D OBJ: Calculate a K given the relevant standard reduction potentials. TOP: The Relationship of E°cell to Delta G° and K 105. The equilibrium constant for a galvanic cell in which 2 moles of electrons are transferred is 2.31 104. What is the standard cell potential for this reaction? a. 0.258 V b. 0.129 V c. 2.93 V d. 0.0560 V e. 0.0645 V ANS: B OBJ: Calculate a cell potential given K. TOP: The Relationship of E°cell to Delta G° and K 106. The equilibrium constant, at 25C, for the reaction below is 1.34 1077. What is E0 for this reaction? 2Tl + BrO3 + 6H+ 2Tl3+ + Br + 3H2O a. b. c. d. e.
0.761 V 0.900 V 0.315 V 0.223 V 1.03 V
ANS: A OBJ: Calculate a cell potential given K. TOP: The Relationship of E°cell to Delta G° and K 107. The equilibrium constant, at 25C, for the reaction below is 1.99 1020. What is E0 for this reaction? NO3 + 3H+ + Cu Cu2+ + HNO2 + H2O a. b. c. d. e.
0.0900 V 0.601 V 0.885 V 1.05 V 0.215 V
ANS: B OBJ: Calculate a cell potential given K. TOP: The Relationship of E°cell to Delta G° and K
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108. Which of the following statements about dry cells is incorrect? a. A primary cell is not rechargeable. b. Dry cells are not really "dry" but contain a moist mixture. c. A LeClanche dry cell has Zinc oxidized and NH4+ being reduced. d. Alkaline dry cells offer improved performance because they are secondary cells. e. The voltage of an alkaline dry cell is approximately 1.5 V. ANS: D OBJ: Identify the incorrect description of a dry cell. TOP: Dry Cells 109. Which of the following voltaic cells is incorrectly labeled? a. Leclanche dry cell / primary b. alkaline dry cell / primary c. mercury battery / secondary d. lead storage battery / secondary e. nickel-cadmium cell / secondary ANS: C OBJ: Identify the incorrect classification of a voltaic cell. TOP: Dry Cells 110. Which of the following is not a feature of the lead storage battery? a. The electrolyte is hydrochloric acid. b. Lead is oxidized at the anode. c. PbO2 is reduced at the cathode. d. Lead (II) sulfate forms during discharge and sticks to the electrodes. e. The lead storage battery is a secondary cell. ANS: A OBJ: Identify the incorrect description of a lead storage battery. TOP: The Lead Storage Battery 111. Which of the following statements concerning the lead storage battery is incorrect? a. Both the anode and the cathode produce PbSO4. b. Automobile 12-volt batteries have six 2-volt cells connected in series. c. All PbSO4 produced is converted back to Pb and PbO2 during recharge of the battery. d. Batteries can be tested by measuring the density of the battery solution. e. Lead batteries represent one of the most successful recycling programs. ANS: C OBJ: Identify the incorrect description of a lead storage battery. TOP: The Lead Storage Battery 112. Which of the following is not a feature of the Nickel Cadmium (Nicad) Cell? a. The Nicad cell is a very common secondary cell. b. Nickel is oxidized at the anode. c. The Nicad cell has a limited number of recharge cycles. d. NiO2 is reduced at the cathode. e. During discharge, the solid reaction products adhere to the electrodes, allowing the cell to be recharged. ANS: B OBJ: Identify the incorrect description of a Nicad cell. TOP: The Nickel – Cadmium (Nicad) Cell Whitten 10e
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113. Which of the following statements concerning the hydrogen-oxygen fuel cell is incorrect? a. Fuel cells are voltaic cells in which the reactants are continuously supplied to the cell and the products are continuously removed. b. Most of the chemical energy from the formation of HO bonds is converted directly into electrical energy. c. The efficiency of energy conversion of the fuel cell is 60-70% of the theoretical maximum, about twice the efficiency of burning hydrogen in a heat engine with a generator. d. The cathode reaction is: H2 + 2OH 2H2O + 2e. e. The H2/O2 cell is nonpolluting, only H2O is released. ANS: D OBJ: Identify the incorrect description of a hydrogen-oxygen fuel cell. TOP: The Hydrogen – Oxygen Fuel Cell 114. Which of the following statements concerning a voltaic cell is/are correct? 1. 2. 3. a. b. c. d. e.
Reduction occurs at the cathode. A voltaic cell consists of two half cells separated by a salt bridge. Anions in the salt bridge flow toward the anode during discharge.
1 only 2 only 3 only 1 and 2 1, 2, and 3
ANS: E DIF: easy OBJ: Identify the statements which correctly describe a voltaic cell. TOP: The Construction of Simple Voltaic Cells 115. The electrochemical reaction which powers a lead-acid storage battery is as follows: Pb(s) + PbO2(s) + 4H+(aq) + 2SO42–(aq) 2PbSO4(s) + 2H2O(l) A single cell of this battery consists of a Pb electrode and a PbO2 electrode, each submerged in sulfuric acid. What reaction occurs at the cathode during discharge? a. Pb(s) is reduced to PbSO4(s). b. PbO2(s) is oxidized to PbSO4(s). c. PbO2(s) is reduced to PbSO4(s). d. Pb(s) is oxidized to PbSO4(s). e. H+ is oxidized to H2O(l) . ANS: B DIF: easy OBJ: Identify the correct description of a lead-acid storage battery. TOP: The Lead Storage Battery
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116. Which of the following statements is true concerning half-cell I as the voltaic cell shown below discharges?
a. b. c. d. e.
[Zn2+] increases with time, and [Cl] increases with time. [Zn2+] decreases with time, and [Cl] increases with time. [Zn2+] decreases with time, and [Cl] decreases with time. [Zn2+] decreases with time, and [NO3] decreases with time. [Zn2+] increases with time, and [NO3] increases with time.
ANS: A DIF: easy OBJ: Identify the correct description of the voltaic cell shown. TOP: The Construction of Simple Voltaic Cells 117. According to the following cell notation, which species is undergoing oxidation? Zn | Zn2+(aq) || Mn2+(aq) | MnO2(s) | Pt(s) a. b. c. d. e.
Mn2+(aq) Zn2+(aq) MnO2(s) Zn(s) Pt(s)
ANS: D DIF: easy OBJ: Identify the requested species given the cell notation. TOP: The Construction of Simple Voltaic Cells 118. In the following electrochemical cell, what is the cathode half reaction? Mn(s) | Mn2+(aq) || Fe3+(aq), Fe2+(aq) | Pt(s) a. b. c. d. e.
Fe3(aq) + e Fe2(aq) Fe2(aq) + e Fe3(aq) Fe2(aq) + Pt(s) Fe3(aq) + e Mn2+(aq) Mn(s) + 2e Mn(s) Mn2+(aq) + 2e
ANS: A DIF: easy OBJ: Identify the requested half-reaction given the cell notation. TOP: The Construction of Simple Voltaic Cells Whitten 10e
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119. What is the correct cell notation for a cell in which the hydrogen electrode is the anode and the cathode half-reaction is Co3+(aq) + e Co2+(aq). a. Pt(s) | H2(g) | H+(aq) || Co3+(aq), Co2+(aq) | Pt(s) b. Pt(s) | H2(g) | H+(aq) || Co3+(aq), Co2+(aq) c. Co2+(aq), Co3+(aq) || H+(aq) | H2(g) | Pt(s) d. Pt(s)| Co2+(aq), Co3+(aq) || H+(aq) | H2(g) | Pt(s) e. H2(g) | H+(aq) || Co2+(aq), Co3+(aq) ANS: A DIF: easy OBJ: Identify the correct cell notation given the cell half reactions. TOP: Standard Electrode Potentials for Other Half-Reactions 120. In a table of standard reduction potentials, the strongest oxidizing agents are the _______ species in the half-reactions with the _______ E° values. a. oxidized, most positive b. reduced, most negative c. reduced, most positive d. oxidized, most negative e. none of these ANS: A DIF: easy OBJ: Complete the description of standard reduction potentials. TOP: Standard Electrode Potentials for Other Half-Reactions 121. Which of the following is true for a reaction that is spontaneous as written? a. G < 0; Ecell > 0 b. G > 0; Ecell < 0 c. G < 0; Ecell < 0 d. G > 0; Ecell > 0 e. G > 0; Ecell = 0 ANS: A DIF: easy OBJ: Identify the sign of delta G and E for the given reaction conditions. TOP: The Relationship of E°cell to Delta G° and K 122. If the value of E°cell is
for the reaction
what is the value of E°cell for ½ Cl2(g) ? a. b. c. d. e.
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ANS: E DIF: easy OBJ: Determine a reaction potential after a change in the reaction stoichiometry and/or reversal of the reaction. TOP: Uses of Standard Electrode Potentials 123. Which of the following statements is true concerning the electrochemical cell depicted below?
Ba | Ba2+(aq) || Mn2+(aq) | Mn Ba2+(aq) + 2eBa(s); E° = –2.91 V 2+ Mn (aq) + 2eMn(s); E° = –1.19 V a. The cell is at equilibrium. b. The cell reaction is spontaneous with a standard cell potential of . c. The cell reaction is spontaneous with a standard cell potential of . d. The cell reaction is nonspontaneous with a standard cell potential of e. The cell reaction is nonspontaneous with a standard cell potential of
. .
ANS: B DIF: moderate OBJ: Identify the correct description of the cell. TOP: Uses of Standard Electrode Potentials 124. Consider the reaction:
3Fe2+(aq) + 2Al(s) 3Fe(s) + 2Al3+(aq) Which of the following statements is true about Fe2+? a. Fe2+ is losing electrons c. Fe2+ is the oxidizing agent 2+ b. Fe is oxidized d. Fe2+ is the reducing agent ANS: C OBJ: Identify the oxidizing agent. TOP: Oxidation and Reduction 125. Which of the following is the correct cell notation for an electrochemical cell consisting of an
anode where Al(s) is oxidized to Al3+(aq) and a cathode where Zn2+(aq) is reduced to Zn(s). (Assume all aqueous solutions have a concentration of 1 mol/L) a. Al(s) | Zn(s) || Al3+(aq) | Zn2+(aq) b. Zn2+(aq) | Zn(s) || Al(s) | Al3+(aq) c. Al3+(aq) | Al(s) || Zn(s) | Zn2+(aq) d. Al(s) | Al3+(aq) || Zn2+(aq) | Zn(s) e. Zn(s) | Zn2+(aq) || Al3+(aq) | Al(s) ANS: D OBJ: Identify the correct representation of the electrochemical cell. TOP: Cell Notation 126. Which of the following is the correct cell notation for an electrochemical cell consisting of an
anode where Fe2+(aq) is oxidized to Fe3+(aq) at a platinum electrode and a cathode where Cu2+(aq) is reduced to Cu(s). (Assume all aqueous solutions have a concentration of 1 mol/L)
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a. b. c. d. e.
Fe2+(aq)| Fe3+(aq) || Cu2+(aq) | Cu(s) Pt(s) | Fe2+(aq), Fe3+(aq) || Cu2+(aq) | Cu(s) Cu(s) | Cu2+(aq) || Fe2+(aq), Fe3+(aq) | Pt(s) Cu(s) | Cu2+(aq) || Fe2+(aq) | Fe3+(aq) Pt(s) | Cu(s) || Fe2+(aq), Fe3+(aq) | Cu2+(aq)
ANS: B OBJ: Identify the correct representation of the electrochemical cell. TOP: Cell Notation
Use the standard reduction potentials below to answer the following questions: Reduction reaction Eo (V) 2.870 F2 + 2e- 2F1.358 Cl2 + 2e Cl2 3+ -2.080 Sc + 2e Sc -0.828 2H2O + 2e- H2 + 2OH2+ -0.763 Zn + 2e Zn 127. Which of the following is the strongest oxidizing agent? a. F2 b. Cl2 c. Sc3+ d. H2O
e. Zn2+
ANS: A OBJ: Identify the strongest oxidizing agent based on standard reduction potentials. TOP: Standard Electrode Potentials 128. Which of the following is the strongest reducing agent? a. F2 b. Cl2 c. Sc3+ d. H2O
e. Zn2+
ANS: C OBJ: Identify the strongest reducing agent based on standard reduction potentials. TOP: Standard Electrode Potentials 129. A voltaic cell is constructed from a standard Al3+|Al half cell (Eored = -1.660V) and a standard
Cr3+|Cr half cell (Eored = 0.740V). Which of the following is the anode reaction? a. H2 2H+ + 2eb. 2H+ H2 + 2ec. Cr3+ Cr + 3ed. Cr Cr3+ + 3ee. H2 + 2e- 2H+ ANS: A OBJ: Identify the anode half reaction given the cell. TOP: Cell Notation
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130. Use the standard reduction potentials given below:
Ni2+ + 2e- Ni Eored = -0.25V 2+ Co + 2e Co Eored = -0.28V to calculate the standard free energy change for the reaction: Ni2+ + Co Ni + Co2+ a. -2.89 kJ b. -5.79 kJ c. -51.4 kJ d. -102.3 kJ
e. -160.8 kJ
ANS: B OBJ: Calculate delta G given the net reaction and standard reduction potentials. TOP: The Relationship of E°cell to Delta G° and K 131. Use the standard reduction potentials given below:
Pb2+ + 2e- Pb Eored = -0.126 V 3+ 2+ Cr + 1e Cr Eored = -0.41 V to calculate the equilibrium constant for the reaction: Pb2+ + 2Cr2+ Pb + 2Cr3+ a. 4.04 x 109 b. 1.00 c. 1.33 x 1063 d. 1.35 x 1018
e. 1.16 x 109
ANS: A OBJ: Calculate K given the standard reduction potentials and the overall reaction. TOP: The Relationship of E°cell to Delta G° and K 132. Use the standard reduction potentials given below:
Fe3+ + 1e- Fe2+ Eored = 0.771V Ag+ + 1e- Ag Eored = 0.799 V Which of the given statements is correct for the following reaction at 298K: Fe3+ + Ag Fe2+ + Ag+ a. Go < 0 b. K < 1 c. n = 2 moles of electrons d. the reaction is product favored e. Eocell > 0 ANS: B OBJ: Identify the correct statement about a reaction given the standard reduction potentials and overall reaction. TOP: The Relationship of E°cell to Delta G° and K 133. Use the standard reduction potentials given below:
Cu2+ + 2e- Cu Eored = 0.337 V Mg2+ + 2e- Mg Eored = -2.37 V What is the calculated value of the cell potential at 298K for an electrochemical cell with the following reaction, when the Cu2+ concentration is 2.51 x 10-4 M and the Mg2+ concentration is 1.05M? Cu2+ + Mg Cu + Mg2+ a. 1.926 V b. 2.140 V c. 2.493 V d. 2.600 V e. 2.814 V ANS: D OBJ: Calculate a cell potential under nonstandard conditions. TOP: The Nernst Equation
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134. How many grams of tin metal will be deposited from a solution that contains Sn2+ ions if a
current of 1.22 A is applied for 71.6 minutes? a. 0.537 g b. 2.17 g c. 3.22 g
d. 6.45 g
e. 8.66 g
ANS: C OBJ: Calculate the mass of metal produced given the current and time. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis 135. How many minutes are required to deposit 0.251 grams of cadmium metal from a solution
that contains Cd2+ ions, if a current of 1.38 A is applied? a. 1.30 min b. 2.48 min c. 4.84 min d. 5.20 min
e. 9.91 min
ANS: D OBJ: Calculate the time required to deposit a mass of metal given also the current. TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis CONCEPTUAL 1. Metal-plated articles are common in our society. Explain why chromium, silver and gold are commonly used, whereas there are no potassium-plated objects. OBJ: Explain why chromium, silver, and gold plating are common but never potassium plating. TOP: Corrosion Protection | Standard Electrode Potentials 2. Battery-powered automobiles have been proposed as a way to reduce emissions from gasoline combustion. What are some of the obstacles that engineers will have to overcome in order for this suggestion to become practical? OBJ: Identify some obstacles to building "practical" battery powered vehicles. TOP: Batteries 3. Explain the following observations: Tin-plated steel cans are protected from oxidation unless the layer of tin is breached, but zinc-coated objects remain protected if the zinc coating is broken. OBJ: Contrast the protection of tin plating with that of zinc plating. TOP: Corrosion Protection 4. Compare the activity series from chapter 4 to the reduction potential table in chapter 21. What can you conclude? OBJ: Compare the activity series to reduction potentials. TOP: Activity Series | Standard Electrode Potentials 5. Propose a reason why a lead storage battery would be more prone to shorting out in the wintertime. (Hint: A cold battery has to be "cranked" for a longer time in order to start the car, making more of the half-reaction products.) OBJ: Suggest why a lead storage battery might short out in the winter. TOP: The Lead Storage Battery
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6. An alternative method to sanitizing pool water is to increase the salinity and pass an electric current through the water as it recirculates. Why would this be an effective treatment? What may have to be added to the water to maintain safety and effectiveness over time? OBJ: Explain why an electric current may be a useful way to sanitize pool water. TOP: Applications of Electric Current 7. When underground ductile iron water pipes are dug up for replacement or fixing they are often found with sand and gravel attached to the pipe in a thick rusty skin covering the pipe. Upon close inspection the pipe is not corroded. Explain. OBJ: Explain the origin and effect of a think rusty skin in the protection of water pipes. TOP: Corrosion
Chapter 22—Nuclear Chemistry MULTIPLE CHOICE 1. Which one of the following statements about nuclear reactions does not correctly distinguish nuclear reactions from ordinary chemical reactions? a. Particles within the nucleus are involved. b. No new elements can be produced. c. Rate of reaction is independent of the presence of a catalyst. d. Rate of reaction is independent of temperature. e. They are often accompanied by the release of enormous amounts of energy. ANS: B OBJ: Identify the description that does not distinguish a chemical reaction from a nuclear reaction. 2. Which statement is false? a. Dalton's theory explained how one element could be converted into another. b. Marie Curie is the only person to receive a Nobel Prize in both physics and chemistry. c. Henri Becquerel discovered natural radioactivity. d. Ernest Rutherford discovered that atoms of one element may be converted into atoms of other elements by spontaneous nuclear disintegrations. e. Marie Curie's daughter Irene and her husband also received a Nobel Prize in chemistry. ANS: A OBJ: Identify the incorrect description of a famous scientist or theory. 3. Which of the following is a nuclear reaction? a. The production of x-rays in the dental office. b. Precipitating silver chloride when silver nitrate is added to a sodium chloride solution. c. The decay of carbon-14 in dead plant tissue. d. The neutralization of hydrochloric acid by a sodium hydroxide solution. e. The electrolysis of molten sodium chloride to produce chlorine gas. ANS: C OBJ: Identify the example of a nuclear reaction. 4. Consider the following statements about the nucleus. Which of these statements is false? a. Neutrons and protons together constitute the nucleus. b. The nucleus is a sizable fraction of the total volume of the atom. c. Electrons occupy essentially empty space around the nucleus. Whitten 10e
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d. Nearly all the mass of an atom resides in the nucleus. e. The nuclei of all elements have approximately the same density. ANS: B OBJ: Identify the incorrect description of the nucleus. TOP: The Nucleus 5. Which of the following is a nucleon? a. electron b. nuclide c. neutron d. isotope e. positron
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ANS: C OBJ: Identify an example of a nucleon. TOP: The Nucleus 6. A term that is used to describe (only) different nuclear forms of the same element is: a. isotopes b. shells c. nucleons d. nuclides e. nuclei ANS: A OBJ: Identify the definition of isotopes. TOP: Neutron-Proton Ratio and Nuclear Stability 7. The most stable nuclides, in general, have ____ numbers of neutrons and ____ numbers of protons. a. odd; even b. odd; odd c. even; even d. even; odd e. odd; equal ANS: C OBJ: Complete the general description of the most stable nuclides. TOP: Neutron-Proton Ratio and Nuclear Stability 8. Which statement concerning stable nuclides and/or the "magic numbers" (such as 2, 8, 20, 28, 50, 82 or 128) is false? a. Nuclides with their number of protons equal to a "magic number" are especially stable. b. Nuclides with their number of neutrons equal to a "magic number" are especially stable. c. Nuclides with the sum of the numbers of their protons and neutrons equal to a "magic number" are especially stable. d. Above atomic number 20, the most stable nuclides have more protons than neutrons. e. The existence of "magic numbers" suggests an energy level (shell) model for the nucleus. ANS: D OBJ: Identify the incorrect example of stable nuclides. TOP: Neutron-Proton Ratio and Nuclear Stability 9. The difference between the sum of the masses of the electrons, protons and neutrons of an atom (calculated mass) and the actual measured mass of the atom is called the ____. a. nuclear mass b. isotopic mass c. decay mass d. critical mass e. mass deficiency ANS: E OBJ: Identify the definition of mass defect. TOP: Nuclear Stability and Binding Energy
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Chapter 26 Values These masses of subatomic particles may be useful for the following question(s). electron 0.00055 amu proton 1.0073 amu neutron 1.0087 amu 10. The actual mass of a atom. a. 0.623 amu b. 0.388 amu c. 0.263 amu d. 0.341 amu e. 0.302 amu
atom is 36.9659 amu. Calculate the mass deficiency (amu/atom) for a
ANS: D OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy 11. Calculate the mass deficiency of a. 0.153 amu b. 0.152 amu c. 0.148 amu d. 0.147 amu e. 0.142 amu
. The actual mass of an
atom is 16.9991 amu.
ANS: E OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy 12. The mass of one atom of a. 1.742 amu b. 1.757 amu c. 0.275 amu d. 0.413 amu e. 0.272 amu
is 29.9738 amu. What is its mass deficiency?
ANS: C OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy 13. Calculate the mass deficiency for an atom of a. 0.951 amu b. 0.934 amu c. 0.952 amu d. 0.941 amu e. 0.937 amu
whose actual mass is 102.9055 amu.
ANS: C OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy
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14. The isotopic mass of a. 0.285 amu b. 0.396 amu c. 0.429 amu d. 0.498 amu e. 0.557 amu
is 58.9332 amu. What is its mass deficiency in amu per atom?
ANS: E OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy 15. The atomic mass of a. 0.665 amu b. 0.718 amu c. 0.690 amu d. 0.703 amu e. 0.687 amu
is 74.9216 amu. What is its mass deficiency?
ANS: D OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy 16. The actual mass of a manganese-55 atom is 54.9381 amu. Calculate its mass deficiency. a. 0.436 amu/atom b. 0.488 amu/atom c. 0.519 amu/atom d. 0.533 amu/atom e. 0.537 amu/atom ANS: C OBJ: Calculate the mass defect of an isotope. TOP: Nuclear Stability and Binding Energy Chapter 26 Values These values may be useful for the following question(s). speed of light = 3.00 108 m/s 1 J = 1 kgm2/s2
1 cal = 4.18 J
17. The mass deficiency for an isotope was found to be 0.410 amu/atom. Calculate the binding energy in J/mol of atoms. a. 3.69 1013 J/mol b. 1.23 1020 J/mol c. 3.69 103 J/mol d. 1.23 103 J/mol e. 1.23 1023 J/mol ANS: A OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy
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18. The mass deficiency of a. 2.48 1013 J/mol b. 1.79 1027 J/mol c. 1.06 1014 J/mol d. 6.19 1010 J/mol e. 5.93 109 J/mol
is 0.2755 amu/atom. Calculate the binding energy in J/mol of atoms.
ANS: A OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy 19. The nuclear binding energy represents: a. the amount of energy that is absorbed from protons and neutrons in forming the nucleus. b. the amount of energy that is released in a fission reaction. c. the amount of energy that is released if the nucleus if formed from initially separate protons and neutrons. d. the amount of energy that is released in a fusion reaction. e. none of these. ANS: C OBJ: Identify the correct description of nuclear binding energy. TOP: Nuclear Stability and Binding Energy 20. The mass deficiency for a. 9.96 1012 J/mol b. 5.44 1012 J/mol c. 6.33 1013 J/mol d. 2.95 1014 J/mol e. 1.20 1015 J/mol
is 0.7029 amu/atom. What is the binding energy in J/mol?
ANS: C OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy 21. The mass deficiency of atoms. a. 2.73 1011 kJ/mol b. 1.16 1010 kJ/mol c. 1.56 1010 kJ/mol d. 1.69 1010 kJ/mol e. 2.77 1011 kJ/mol
is 0.1731 g/mol. Calculate the binding energy for
in kJ/mol of
ANS: C OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy
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22. What is the binding energy of an atom having a mass deficiency of 0.4721 amu per atom? Express your answer in kJ/mol of atoms. a. 5.26 kJ/mol b. 4.25 1010 kJ/mol c. 1.42 kJ/mol d. 4.25 1020 kJ/mol e. 2.77 1011 kJ/mol ANS: B OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy 23. What is the binding energy in kJ/mol of atoms with a mass deficiency of 0.1064 amu/atom? a. 9.58 109 kJ/mol b. 3.20 101 kJ/mol c. 5.48 1033 kJ/mol d. 2.58 1017 kJ/mol e. 2.62 105 kJ/mol ANS: A OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy 24. Calculate the nuclear binding energy in kJ/g of an isotope that has a mass deficiency of 0.6050 amu/atom. The isotope has a mass of 63.9280 amu. a. 5.44 1010 kJ/g b. 1.89 1010 kJ/g c. 2.97 108 kJ/g d. 3.48 1012 kJ/g e. 8.52 108 kJ/g ANS: E OBJ: Calculate the binding energy given the mass defect. TOP: Nuclear Stability and Binding Energy 25. Calculate the binding energy (in J/mol) for a. 2.86 1013 J/mol b. 1.22 1014 J/mol c. 8.57 1013 J/mol d. 2.86 105 J/mol e. 8.75 1016 J/mol
whose isotopic mass is 102.9055 amu.
ANS: C OBJ: Calculate the binding energy of an isotope. TOP: Nuclear Stability and Binding Energy 26. Calculate the binding energy (in J/mol) for a. 4.45 1016 J/mol b. 5.45 1013 J/mol c. 1.82 108 J/mol d. 5.54 1019 J/mol e. 5.75 1015 J/mol Whitten 10e
whose isotopic mass is 63.9280 amu.
Test Bank
792
ANS: B OBJ: Calculate the binding energy of an isotope. TOP: Nuclear Stability and Binding Energy 27. Which isotope below has the highest nuclear binding energy per gram? (No calculations are necessary.) a. b. c. d. e. ANS: D OBJ: Identify the isotope with the greatest nuclear binding energy per gram. TOP: Nuclear Stability and Binding Energy 28. Which isotope below has the smallest nuclear binding energy per gram? (No calculations are necessary.) a. b. c. d. e. ANS: A OBJ: Identify the isotope with the smallest nuclear binding energy per gram. TOP: Nuclear Stability and Binding Energy 29. Which statement concerning average nuclear binding energy per gram of nuclei is false? a. For nuclei with small mass numbers, it increases rapidly with increasing mass number. b. It reaches a maximum around mass number 50. c. It decreases slowly with increasing mass number for nuclei with mass numbers greater than 50. d. The nuclei with the highest binding energies (mass numbers 40 to 150) are the most stable. e. Nuclei with mass numbers greater than 210 can easily be decomposed into protons and neutrons. ANS: E OBJ: Identify the incorrect description of nuclear binding energy. TOP: Nuclear Stability and Binding Energy 30. A positron has a mass number of ____, a charge of ____, and a mass equal to that of a(n) ____. a. 0; 1+; proton b. 1; 2+; proton c. 0; 1+; electron d. 1; 2+; electron e. 0; 0; proton
Whitten 10e
Test Bank
793
ANS: C OBJ: Complete the description of a positron. TOP: Radioactive Decay 31. A beta particle has a mass number of ____, a charge of ____, and a mass equal to that of a(n) ____. a. 1; 1+; proton b. 1; 0; neutron c. 0; 1; electron d. 0; 1+; electron e. 4; 2+; helium nucleus ANS: C OBJ: Complete the description of a beta particle. TOP: Radioactive Decay 32. Which of the following particles or rays has the greatest penetrating ability? a. beta particles b. alpha particles c. protons d. positrons e. gamma rays ANS: E OBJ: Identify the most penetrating particle or ray. TOP: Radioactive Decay 33. Which of the following statements about gamma rays is false? a. Gamma rays have great penetrating power and severely damage both skin and internal organs. b. They travel at the speed of light. c. They are a common type of radiation emitted in decay processes. d. They can be stopped by a thin layer of concrete or lead. e. They have no mass. ANS: D OBJ: Identify the incorrect description of gamma rays. TOP: Radioactive Decay 34. The sum of the mass numbers of the reactants must equal which of the following? a. The sum of the mass numbers of the products. b. The sum of the atomic numbers of the products. c. The sum of the atomic numbers of the reactants. d. The sum of the binding energies of the products. e. The number of nucleons which are transformed. ANS: A OBJ: Complete the statement regarding equations for nuclear reactions. TOP: Equations for Nuclear Reactions 35. Which of the following does not apply to a balanced nuclear reaction? a. charge balance b. mass balance c. total number of nucleons remains the same d. protons can turn into neutrons, or vice-versa e. same number and kind of atoms on both sides of the equation Whitten 10e
Test Bank
794
ANS: E OBJ: Identify the factor that does not apply in balancing nuclear reactions. TOP: Equations for Nuclear Reactions 36. If a radioisotope lies above the "band of stability," one would predict that it would decay by ____. a. alpha emission b. beta emission c. positron emission d. electron capture e. K capture ANS: B OBJ: Predict the mode of radioisotope decay given its location relative to the band of stability. TOP: Neutron-Rich Nuclei (Above the Band of Stability) 37. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: B OBJ: Complete and balance the given nuclear decay. TOP: Neutron-Rich Nuclei (Above the Band of Stability) 38. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: C OBJ: Complete and balance the given nuclear decay. TOP: Neutron-Rich Nuclei (Above the Band of Stability)
Whitten 10e
Test Bank
795
39. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: C OBJ: Complete and balance the given nuclear decay. TOP: Neutron-Rich Nuclei (Above the Band of Stability) 40. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: D OBJ: Complete and balance the given nuclear reaction. TOP: Neutron-Rich Nuclei (Above the Band of Stability) 41. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: B OBJ: Complete and balance the given nuclear reaction. TOP: Neutron-Rich Nuclei (Above the Band of Stability)
Whitten 10e
Test Bank
796
42. Complete and balance the following equation. The missing term is ____. a. b. c. d. e. ANS: D OBJ: Complete and balance the given nuclear reaction. TOP: Neutron-Poor Nuclei (Below the Band of Stability) 43. The alpha emission by lead-204 results in the product isotope ____. a. b. c. d. e. ANS: C OBJ: Identify the product isotope of a nuclear decay process. TOP: Neutron-Poor Nuclei (Below the Band of Stability) 44. If the nucleus a.
decays by an electron capture, the resulting isotope would be ____.
b. c. d. e. ANS: E OBJ: Identify the product isotope of a nuclear decay process. TOP: Neutron-Poor Nuclei (Below the Band of Stability) 45. A radioisotope of argon, ____. a. neutron emission b. beta emission c. electron capture d. alpha emission e. fission
, lies below the "band of stability." One would predict that it decays via
ANS: C OBJ: Predict the mode of radioisotope decay given its location relative to the band of stability. TOP: Neutron-Poor Nuclei (Below the Band of Stability) Whitten 10e
Test Bank
797
46. Which one of the following represents K capture? a. b. c. d. e. ANS: B OBJ: Identify an example of K capture. TOP: Neutron-Poor Nuclei (Below the Band of Stability) 47. All nuclides with atomic number greater than ____ are beyond the band of stability. a. 43 b. 80 c. 86 d. 83 e. 90 ANS: D OBJ: Identify the limits of the band of stability. TOP: Nuclei with Atomic Number Greater than 83 48. The conversion of a. beta emission b. K capture c. alpha emission d. positron emission e. fission
to
occurs via ____.
ANS: C OBJ: Classify the described nuclear reaction. TOP: Nuclei with Atomic Number Greater than 83 49. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: B OBJ: Complete and balance the given nuclear reaction. TOP: Nuclei with Atomic Number Greater than 83
Whitten 10e
Test Bank
798
50. Complete and balance the following equation. The missing term is ____.
a. b. c. d. e. ANS: E OBJ: Complete and balance the given nuclear reaction. TOP: Nuclei with Atomic Number Greater than 83 51. A Geiger-Muller counter is a ____. a. photographic detector b. gas ionization counter c. cloud chamber d. fluorescence detector e. spectrophotometer ANS: B OBJ: Complete the description of a Geiger-Muller counter. TOP: Detection of Radiations 52. A substance that absorbs high energy radiation such as gamma rays and subsequently emits visible light is the basis for ____. a. photographic detection b. a scintillation counter c. a cyclotron d. a Geiger-Muller counter e. a linear accelerator ANS: B OBJ: Recognize the description of a scintillation counter. TOP: Detection of Radiations 53. Consider the following statements about radioactive decay. Which statement is true? a. The rates of all radioactive decays depend on temperature. b. The rate of decay follows second-order kinetics. c. About 5 half-lives must pass for any radionuclide to lose 99.9% of its radioactivity. d. Every radionuclide shows a different shape of exponential decay curve. e. The rate constant, k, is different for each radionuclide. ANS: E OBJ: Identify the correct description of radioactive decay. TOP: Rates of Decay and Half-life
Whitten 10e
Test Bank
799
54. The half-life of Kr-79 is 35.0 hours. What is the value of the specific rate constant, k? a. 0.639 h1 b. 0.0571 h1 c. 24.3 h1 d. 0.0198 h1 e. 0.0086 h1 ANS: D OBJ: Calculate the decay rate constant given half-life. TOP: Rates of Decay and Half-life 55. The half-life of Tc-99 is 2.13 105 years. What is the value of the specific rate constant, k? a. 3.25 106 y1 b. 1.41 106 y1 c. 4.69 106 y1 d. 0.693 y1 e. 1.48 105 y1 ANS: A OBJ: Calculate the decay rate constant given half-life. TOP: Rates of Decay and Half-life 56. The half-life of polonium-211 is 0.52 s. What is the value of the specific rate constant, k? a. 0.36 s1 b. 0.75 s1 c. 0.67 s1 d. 1.50 s1 e. 1.33 s1 ANS: E OBJ: Calculate the decay rate constant given half-life. TOP: Rates of Decay and Half-life 57. The specific rate constant for the decay of Tc-95 is 0.0346 h1. What is its half-life? a. 10.6 h b. 8.70 h c. 28.9 h d. 0.0499 h e. 20.0 h ANS: E OBJ: Calculate half-life given the rate constant . TOP: Rates of Decay and Half-life 58. The specific rate constant for the decay of Bi-210 is 0.138 d1. What is its half-life? a. 0.20 d b. 2.18 d c. 5.02 d d. 0.096 d e. 3.84 d ANS: C OBJ: Calculate half-life given the rate constant . TOP: Rates of Decay and Half-life Whitten 10e
Test Bank
800
59. The half-life of 3.25 105 y? a. 0.0102 g b. 0.240 g c. 0.0240 g d. 1.02 g e. 1.04 g
is 3.25 104 y. How much of an initial 10.40 microgram sample remains after
ANS: A OBJ: Calculate the mass of sample remaining after the specified time. TOP: Rates of Decay and Half-life 60. The half-life of Sr-83 is 32.4 hours. How much of a 20.0-mg sample of hours? a. 3.68 mg b. 0.249 mg c. 4.02 mg d. 0.497 mg e. 4.62 mg
will be left after 75.0
ANS: C OBJ: Calculate the mass of sample remaining after the specified time. TOP: Rates of Decay and Half-life 61. Nitrogen-13 has a half-life of 9.97 minutes. How much of a 10.0-g sample remains after 60.0 minutes? a. 9.2 g b. 0.15 g c. 0.35 g d. 1.2 g e. 2.5 g ANS: B OBJ: Calculate the mass of sample remaining after the specified time. TOP: Rates of Decay and Half-life 62. How long would it take for 2.8 micrograms of a 10.4 microgram sample of
to decay? The half-
life of is 3.25 104 y. a. 1.2 105 y b. 6.2 104 y c. 1.5 104 y d. 8.1 106 y e. 4.0 105 y ANS: C OBJ: Calculate the time required for the sample to decay. TOP: Rates of Decay and Half-life
Whitten 10e
Test Bank
801
63. Cobalt-60 has a half-life of 5.27 years. How long will it require for 10.5 mg of a 22.8-mg sample of to decay? a. 3.98 y b. 4.71 y c. 2.05 y d. 2.57 y e. 5.92 y ANS: B OBJ: Calculate the time required for the sample to decay. TOP: Rates of Decay and Half-life 64. The half-life of 33P is 25.3 days. How long will it take for 64.0 g to decay to 1.0 g? a. 150 d b. 350 d c. 210 d d. 120 d e. 100 d ANS: A OBJ: Calculate the time required for the sample to decay. TOP: Rates of Decay and Half-life 65. A 20.0-g sample of 277Th decays to 17.0 g in 3.00 days. What is the rate constant for the decay of this isotope? a. 1.9 d1 b. 0.49 d1 c. 1.50 d1 d. 0.054 d1 e. 0.12 d1 ANS: D OBJ: Calculate the decay rate constant given the initial and final mass of the sample and decay time. TOP: Rates of Decay and Half-life 66. If two-thirds of a radon-86 sample decays in 6.1 days, what is the half-life of this isotope? a. 1.18 d b. 0.41 d c. 0.10 d d. 4.2 d e. 3.8 d ANS: E OBJ: Calculate the half-life given the change in sample composition and decay time. TOP: Rates of Decay and Half-life 67. The radionuclides 238U, 235U, and 232Th cannot attain nuclear stability by only one nuclear reaction. Instead they decay in a series of disintegrations. All end with a stable isotope of the element ____. a. Ar b. Co c. Bi d. Rn e. Pb
Whitten 10e
Test Bank
802
ANS: E OBJ: Identify the element that marks the end of the decay process for uranium and thorium isotopes. TOP: Decay Series 68. For any particular decay step, the decaying nuclide is called the ____ nuclide and the decay results in the ____ nuclide. a. reactant; product b. parent; daughter c. initial; final d. mother; daughter e. parent; product ANS: B OBJ: Complete the description of the decay process. TOP: Decay Series 69. What is not a practical use of radionuclides? a. Radioactive dating to estimate the age of an article. b. Irradiation of some foods in order to transmutate poisonous elements into nonpoisonous elements. c. To be power sources of heart pacemakers. d. To act as radioactive tracers in medicine, in chemical research, and plant studies. e. Serves as radioactive source in smoke detectors. ANS: B OBJ: Identify the impractical use of radionuclides. TOP: Uses of Radionuclides 70. Charcoal found in an old tomb has a carbon-14 activity that is 0.366 times that of present dry wood. Estimate the age of the wood. The half-life of C-14 is 5730 years. a. 1.64 103 y b. 8.31 103 y c. 3.77 103 y d. 3.61 103 y e. 6.98 102 y ANS: B OBJ: Calculate the age of an object using data from carbon dating. TOP: Uses of Radionuclides 71. A rock contains 3.008 mg of 238U and 0.624 mg of 206Pb. The half-life of 238U is 4.51 109 years. Estimate the age of the rock. a. 1.02 1010 y b. 3.74 104 y c. 1.39 109 y d. 6.12 108 y e. 1.12 109 y ANS: C OBJ: Calculate the age of an object using data from natural U-238 decay. TOP: Uses of Radionuclides
Whitten 10e
Test Bank
803
72. The radioisotope ____ is used to monitor goiter and other thyroid problems. a. 201Tl b. 99Mo c. 238U d. 40K e. 123I ANS: E OBJ: Identify the radioisotope used for a certain medical procedure. TOP: Uses of Radionuclides 73. A sample of uranium ore is found to contain 6.58 mg of 238U and 1.44 mg of 206Pb. Estimate the age of the ore. The half-life of 238U is 4.51 109 years. a. 9.87 109 yr b. 1.46 109 yr c. 1.54 1010 yr d. 6.84 1010 yr e. 1.01 109 yr ANS: B OBJ: Calculate the age of an object using data from natural U-238 decay. TOP: Uses of Radionuclides 74. A cyclotron cannot be used to accelerate ____. a. protons b. alpha particles c. electrons d. neutrons e. deuterons ANS: D OBJ: Identify the particle that cannot be accelerated in a cyclotron. TOP: Artificial Transmutations of Elements 75. Particle accelerators are able to do all the following except: a. Accelerate electrons. b. Synthesize technetium. c. Synthesize artificial isotopes. d. Initiate fission reactions. e. Enable bombarding nuclei to collide with the target nucleus. ANS: D OBJ: Identify the incorrect description of what a particle accelerator can do. TOP: Artificial Transmutations of Elements 76. Which of the following would you expect to have the highest binding energy per nucleon? a. b. c. d. e.
Whitten 10e
Test Bank
804
ANS: C OBJ: Identify the isotope with the highest binding energy per nucleon. TOP: Nuclear Fission 77. Which one of the following reactions represents fission? a. b. c. d. e. ANS: D OBJ: Identify the nuclear equation of a fission reaction. TOP: Nuclear Fission 78. Consider the fission of 235U. If sufficient fissionable material, called the ____, is contained in a small enough volume, a sustained chain reaction can result. a. critical mass b. nuclear mass c. mass deficiency d. fission mass e. parent mass ANS: A OBJ: Recognize the definition of critical mass. TOP: Nuclear Fission 79. Which one of the components of a light water reactor listed below is described by an incorrect function?
a. b. c. d. e.
Component / Function moderator / slows neutrons fuel / supplies neutrons plus heat cooling system / coolant for the reactor control rods / absorb some neutrons to control rate of fission shielding prevents the absorption of beta gamma rays by the fuel and cooling system
ANS: E OBJ: Identify the incorrect description of a light water reactor component. TOP: Nuclear Fission Reactors 80. Which of the following is not a hazard or problem resulting from the use of nuclear reactors to produce power? a. Proper shielding precautions must be taken to protect people. b. The possibility of a "meltdown" if the cooling system fails. c. The safe handling and storage of spent fuel for hundreds of thousands of years because it contains long-lived radionuclides. d. The possibility of a nuclear explosion occurring. e. The possibility of theft for use in constructing atomic weapons. ANS: D OBJ: Identify the description that is not a hazard of nuclear reactors. TOP: Nuclear Fission Reactors Whitten 10e
Test Bank
805
81. Which one of the following represents fusion? a. b. c. d. e. ANS: E OBJ: Identify the nuclear equation for a fusion reaction. TOP: Nuclear Fusion 82. Which one of the following would be most likely to undergo fusion under the proper conditions? a. b. c. d. e. ANS: A OBJ: Identify the isotope most likely to undergo fusion. TOP: Nuclear Fusion 83. The major problem associated with the development of fusion for controlled energy generation is ____. a. containment of radioactive products of fusion b. relatively low energy yield per gram of fuel c. containment of extremely high temperature plasmas d. depletion of water reserves which serve as a source of fuel e. the resulting air pollution ANS: C OBJ: Identify a major problem in the development of commercial fusion power plants. TOP: Nuclear Fusion 84. Solar energy is generated by a(n) ____ reaction. a. fission b. fusion c. beta emission d. electron capture e. alpha emission ANS: B OBJ: Identify the nuclear reaction responsible for solar energy. TOP: Nuclear Fusion
Whitten 10e
Test Bank
806
Dynamic Questions 85. What is the percent activity of a radioactive sample (relative to its original activity) that has undergone three half-lives of decay? a. 12.5% b. 6.25% c. 25.0% d. 3.13% e. 75.0% ANS: A DIF: easy OBJ: Calculate the percent activity after a given number of half-lives of decay. TOP: Rates of Decay and Half-life 86. Consider a certain type of nucleus that has a rate constant of 2.94 10-2 min-1. Calculate the time required for the sample to decay to one-fourth of its initial value. a. 23.6 min b. 29.5 min c. 0.0588 min d. 47.1 min e. 2.94 min ANS: D DIF: moderate OBJ: Calculate the time required to decay given the rate constant. TOP: Rates of Decay and Half-life 87. A sample of a radioactive isotope is found to have lost 34.9% of its original activity after 3.63 days. What is the decay constant of this isotope? a. 0.118 d b. 0.290 d c. 1.56 d d. 0.0825 d e. 1.15 d ANS: A DIF: easy OBJ: Determine the rate constant given the percent activity after a specified time. TOP: Rates of Decay and Half-life 88. Which particle does the nuclide symbol a. positron b. gamma ray c. helium nucleus d. proton e. electron
represent?
ANS: A DIF: easy OBJ: Match the Greek symbol with the particle name. TOP: Equations for Nuclear Reactions
Whitten 10e
Test Bank
807
89. When a. b. c. d. e.
undergoes beta emission, what is the product nuclide?
ANS: E DIF: easy OBJ: Determine the product nuclide for a beta decay. TOP: Equations for Nuclear Reactions 90. When the radioactive nuclide a. b. c. d. e.
undergoes alpha emission, what is the product nuclide?
ANS: D DIF: easy OBJ: Determine the product nuclide of an alpha decay. TOP: Equations for Nuclear Reactions 91. Which of the following is the most probable mode of radioactive decay for the radioactive nuclide ? a. b. c. d. e.
beta emission gamma emission neutron emission alpha emission positron emission
ANS: A DIF: easy OBJ: Predict the type of radioactive decay given the isotope. TOP: Neutron-Rich Nuclei (Above the Band of Stability) 92. What is the product nuclide if
U undergoes three successive alpha decays?
a. b. c. d. e. none of the above ANS: A DIF: easy OBJ: Predict the product isotope of successive alpha decays. TOP: Equations for Nuclear Reactions
Whitten 10e
Test Bank
808
93. A particular nuclear bombardment reaction is represented by the abbreviated notation What is the identity of the nuclide X? a.
.
b. c. d. e. ANS: A DIF: easy OBJ: Determine the product nucleus in a nuclear bombardment reaction. TOP: Equations for Nuclear Reactions 94. After 2.8 hours, of the initial amount of a particular radioactive nuclide remains unchanged. What is the half-life of the nuclide? a. 28 min b. 45 min c. 60 min d. 64 min e. 20 min ANS: A DIF: easy OBJ: Determine the half-life given the time of decay and remaining amount of material. TOP: Rates of Decay and Half-life 95. Rank the following types of radiation from least penetrating to most penetrating:
or a. b. c. d. e. ANS: A OBJ: Rank the penetration ability of radiation. TOP: Radioactive Decay 96. Which of the following characterizes an alpha ray? a. Is more penetrating than a gamma ray b. Is attracted to the negatively charged plate in an electric field c. Carries a negative charge d. Is composed of electrons e. Two of the above ANS: B OBJ: Describe an alpha ray. TOP: Radioactive Decay
Whitten 10e
Test Bank
809
97. Which of the following characterizes a beta ray? a. Is more penetrating than a gamma ray b. Is attracted to the negatively charged plate in an electric field c. Carries a positive charge d. Is a product of natural radioactive decay e. Two of the above ANS: D OBJ: Describe a beta ray. TOP: Radioactive Decay 98. Which of the following characterizes a gamma ray? a. Is more penetrating than an alpha ray b. Is attracted to the positively charged plate in an electric field c. Is composed of electrons d. Is not deflected by an electric field e. Two of the above ANS: E OBJ: Describe a gamma ray. TOP: Radioactive Decay 99. When uranium-238 undergoes alpha decay, the symbol of the daughter nuclide (product
nuclide) is: a.
b.
c.
d.
e.
ANS: B OBJ: Identify the product isotope of a nuclear decay process. TOP: Radioactive Decay 100. When the nuclide lead-210 undergoes beta decay, the symbol of the daughter nuclide (product
nuclide) is: a.
b.
c.
d.
e.
ANS: A OBJ: Identify the product isotope of a nuclear decay process. TOP: Radioactive Decay 101. When the nuclide magnesium-20 undergoes positron emission, the symbol of the daughter
nuclide (product nuclide) is: a.
b.
c.
d.
e.
ANS: D OBJ: Identify the product isotope of a nuclear decay process. TOP: Radioactive Decay 102. Based on nuclear stability, what is the symbol for the most likely product when phosphorus-
32 undergoes decay? a.
b.
c.
d.
e.
ANS: B OBJ: Predict the decay product based on nuclear stability. TOP: Neutron-Proton Ratio and Nuclear Stability Whitten 10e
Test Bank
810
103. What is the binding energy in kJ/mol nucleons for copper-65? a. b. c. d. e.
= 1.00783 g/mol = 1.00867 g/mol 8.454 x 108 kJ/mol nucleons 8.373 x 108 kJ/mol nucleons 5.495 x 1010 kJ/mol nucleons 2.684 x 1012 kJ/mol nucleons 4.129 x 1010 kJ/mol nucleons
= 64.92780 g/mol
ANS: A OBJ: Calculate the binding energy of an isotope. TOP: Nuclear Stability and Binding Energy CONCEPTUAL 1. Matter has successfully been converted into energy in nuclear reactions. What do you think would have to happen in order to successfully convert energy into matter? OBJ: Suggest what would be necessary to convert energy into matter. TOP: Nuclear Fission | Nuclear Fusion | Nuclear Stability and Binding Energy 2. Make arguments for and against nuclear power. Use facts, not emotions, in your discussion. OBJ: Advocate for and against nuclear power. TOP: Nuclear Fission Reactors | Rates of Decay and Half-life 3. Describe the sequence of events in a new star, which starts out with hydrogen atoms involved in fusion. What happens when the hydrogen supply is exhausted? Where do elements other than hydrogen and helium come from? OBJ: Describe changes in composition of a star during its life. TOP: Nuclear Fusion | The Life-Cycle of a Star 4. How is it possible that such a small amount of matter can be converted into such a tremendous amount of energy in a fusion reaction? OBJ: Explain the magnitude of energy released from a fusion reaction. TOP: Nuclear Fusion 5. In how many areas of your daily life do nuclear reactions play a role? OBJ: List the areas of your life where nuclear reactions play a role. TOP: Application of Nuclear Processes 6. Examine the positions, on the periodic table, of the elements with "magic numbers" of protons. Can you find any reason for their stability? Now determine where on the periodic table element 126 (a magic number) would be. Does it fit in with your reasoning? OBJ: Correlate the high stability of elements with "magic numbers" of protons with their location on the periodic table and suggest a reason for their stability. TOP: Nuclear Stability and Binding Energy
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811
7. The most stable nucleus of all the known isotopes is 56Fe. Based on this fact what type of reaction would generate excess energy with nuclei lighter than 56? Heavier? Is it possible to generate energy from a nuclear reaction using 56Fe? OBJ: Describe the limits of nuclear fission and fusion reactions which release energy. TOP: Nuclear Stability and Binding Energy | Nuclear Fusion | Nuclear Fission
Chapter 24—Organic Chemistry II: Shapes, Selected Reactions, and Biopolymers MULTIPLE CHOICE 1. Which of the following is a pair of constitutional (or structural) isomers? a. 1-bromobutane and 1-bromopentane b. benzene and cyclohexane c. 1-bromobutane and 2-bromobutane d. ethanol and methanol e. cis-2-butene and trans-2-butene ANS: C OBJ: Identify the pair of structural isomers given the compound names. TOP: Constitutional Isomers 2. Below are five pairs of constitutional isomers. One pair has different functional groups. Which pair has the different functional groups? a.
b. CH2=CHCH=CHCH3 and CH2=CHCH2CH=CH2 c. CH3CH2OH and CH3OCH3 d. CH3CH2CH2CH3 and e. CH3CH2CH2Br and ANS: C OBJ: Identify the structural isomers with different functional groups given the structural formulas. TOP: Constitutional Isomers 3. Which of the following is a constitutional isomer of 2-pentanone that has a different functional group? a. 3-pentanone b. 2-butanone c. 2-pentanal d. pentanal e. 2-pentanol ANS: D OBJ: Identify the name of a constitutional isomer given the name of one of the isomers. Whitten 10e
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812
TOP: Constitutional Isomers
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813
4. Which of the following compounds does not have a constitutional isomer with a different functional group? a. propanone (acetone) b. 3-pentanone c. ethanol d. dimethyl ether e. ethanal (acetaldehyde) ANS: E OBJ: Identify the name of the compound that does not have a constitutional isomer with a different functional group. TOP: Constitutional Isomers 5. Which of the following statements about constitutional isomers is false? a. Constitutional isomers have the same molecular formula. b. Constitutional isomers have different structural formulas. c. Constitutional isomers always have the same boiling point. d. Constitutional isomers differ in the order in which their atoms are bonded. e. Sometimes constitutional isomers have different functional groups present. ANS: C OBJ: Identify the incorrect description of constitutional isomers. TOP: Constitutional Isomers 6. What are the two types of stereoisomers? a. geometrical and optical b. optical and positional c. geometrical and positional d. geometrical and functional group e. chiral and optical ANS: A OBJ: Identify the two types of stereoisomers. TOP: Stereoisomers 7. Which of the following is a chiral molecule? a. CH3CBr2Cl b. CBrCl2I c. CH3CHBrCH2CH3 d. (CH3)2CHCl e. CH2BrI ANS: C OBJ: Identify the chiral molecule given condensed structural formulas. TOP: Stereoisomers 8. Does the following compound have any asymmetric carbons? If so, which one (or ones)?
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a. b. c. d. e.
1 3 2 1 and 2 1, 2, and 3
ANS: B OBJ: Identify the asymmetric carbons given the structural formula. TOP: Stereoisomers 9. Which of the following compounds can have geometrical isomers? a. 1,1-dichloroethene b. 2,3-dichloropropene c. 1,2-dichloropropane d. 1,2-dichlorocyclobutane e. 3-ethyl-3-hexene ANS: D OBJ: Identify the name of the compound which has geometrical isomers. TOP: Stereoisomers 10. Which statement concerning optical isomers is false? a. Optical isomers have identical physical properties, except for their interaction with polarized light. b. A racemic mixture is a single sample containing equal amounts of the two optical isomers of a compound. c. Each optical isomer of a compound rotates polarized light by equal amounts but in opposite directions. d. A racemic mixture does not rotate the plane of polarized light because the effects of the two isomers exactly cancel. e. Optical isomers react exactly the same with any particular compound. ANS: E OBJ: Identify the incorrect description of optical isomers. TOP: Stereoisomers 11. Which one of the following statements about the isomers of butane is false? a. Butane has staggered and eclipsed conformational isomers. b. Butane and isobutane are geometric isomers. c. The staggered conformation of butane is more stable than the eclipsed conformation. d. Staggered and eclipsed conformations are not constitutional isomers. e. Butane and isobutane do not have optical isomers. ANS: B OBJ: Identify the incorrect description of isomers of butane. TOP: Stereoisomers
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815
12. Cyclohexane can assume two different geometries, chair and twist boat. What is the relationship between these two forms? a. optical isomers b. geometric isomers c. structural isomers d. conformational isomers e. constitutional isomers ANS: D OBJ: Identify an example of conformational isomers. TOP: Conformations 13. Which of the following statements concerning isomers and conformations is false? a. Conformations of a compound differ in the extent of rotation about one or more single bonds. b. A staggered conformation is slightly more stable than the eclipsed conformation. c. At least one chemical bond must be broken and reformed to convert one isomer into another. d. In the staggered conformation, there is less repulsive interaction between H atoms on adjacent C atoms. e. The chair and twist boat forms are two isomers of cyclohexane. ANS: E OBJ: Identify the incorrect description of isomers and conformations. TOP: Conformations 14. Conversion of one form of a molecule into another form by rotation about a CC single bond occurs very rapidly at room temperature. These different forms of the molecule are known as ____. a. constitutional isomers b. optical isomers c. geometric isomers d. conformations e. enantiomers ANS: D OBJ: Recognize the definition of conformations. TOP: Conformations 15. What are the products of the reaction of ethanol and metallic sodium? a. CH3CH2CH2CH2 and NaOH b. CH3CH2OCH2CH3, NaH, and NaOH c. CH3CH2O, Na+, and H2 d. CH3CH3 and NaOH e. CH3O, Na+, and H2 ANS: C OBJ: Identify the products given the reactants. TOP: Reactions of Brønsted-Lowry Acids and Bases 16. Which of the following classes of organic compounds has the greatest acid strength? a. phenols b. alcohols c. carboxylic acids d. amines e. substituted ammonium ions Whitten 10e
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816
ANS: C OBJ: Identify the most acidic class of organic compounds. TOP: Reactions of Brønsted-Lowry Acids and Bases 17. The reaction of methylamine with hydrochloric acid produces ____. a. ammonia b. ammonium methylate c. methylammonium chloride d. chloromethane e. chloromethylamine ANS: C OBJ: Identify the products given the reactants. TOP: Reactions of Brønsted-Lowry Acids and Bases 18. The pKb for CH3NH2 is 3.30. What is the value for the Ka of CH3NH3+? a. 2.0 103 b. 5.0 104 c. 2.0 1011 d. 5.0 1010 e. 5.0 1018 ANS: C OBJ: Calculate Ka given the pKb. TOP: Reactions of Brønsted-Lowry Acids and Bases 19. The Ka for formic acid (HCOOH) is 1.8 104. What is the pKb for the formate ion (HCOO)? a. 3.74 b. 10.26 c. 1.87 d. 12.13 e. 5.6 1011 ANS: B OBJ: Calculate pKb given the Ka. TOP: Reactions of Brønsted-Lowry Acids and Bases 20. The Ka values for acetic acid and ethanol are 1.8 105 and 1 1018, respectively. Which of the following statements is true? a. Acetate is a weaker base than ethoxide (CH3CH2O). b. Acetic acid is a weaker acid than ethanol. c. Ethanol reacts easily with strong bases. d. Acetic acid and ethanol are both characterized as strong acids. e. Acetic acid and ethanol are both carboxylic acids. ANS: A OBJ: Identify the incorrect description two molecules and their equilibrium constants. TOP: Reactions of Brønsted-Lowry Acids and Bases
Whitten 10e
Test Bank
817
21. Which of the following classes of organic compounds has the greatest strength as a base? a. aromatic amines b. aliphatic amines c. alkoxides d. carboxylates e. phenoxides ANS: C OBJ: Identify the most basic class of organic compounds. TOP: Reactions of Brønsted-Lowry Acids and Bases 22. Which of the following happens during oxidation? a. Gain of electrons. b. An increase in the hydrogen content. c. An increase in the carbon content. d. An increase in the oxygen content. e. A decrease in the oxygen content. ANS: D OBJ: Identify the correct description of oxidation. TOP: Oxidation-Reduction Reactions 23. The reaction of 1-propanol with K2Cr2O7 in acidic solution to produce propanal is what kind of reaction? a. polymerization b. combustion c. oxidation d. reduction e. double displacement ANS: C OBJ: Identify the type of reaction given the reactants and products. TOP: Oxidation-Reduction Reactions 24. The reaction of a secondary alcohol with potassium dichromate in an acidic solution produces a(n) ____. a. carboxylic acid b. aldehyde c. amine d. primary alcohol e. ketone ANS: E OBJ: Identify the products given the reactants. TOP: Oxidation-Reduction Reactions 25. The reduction of an aldehyde produces a(n) ____. a. primary alcohol b. secondary alcohol c. tertiary alcohol d. ketone e. carboxylic acid
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Test Bank
818
ANS: A OBJ: Identify the product of an aldehyde reduction. TOP: Oxidation-Reduction Reactions 26. Catalytic reduction of acetaldehyde produces ____. a. acetic acid b. methanol c. formic acid d. ethanol e. ethene ANS: D OBJ: Identify the product of a catalytic reduction of acetaldehyde. TOP: Oxidation-Reduction Reactions 27. The reduction of a ketone produces a(n) ____. a. primary alcohol b. secondary alcohol c. tertiary alcohol d. aldehyde e. carboxylic acid ANS: B OBJ: Identify the product of a ketone reduction. TOP: Oxidation-Reduction Reactions 28. The reduction of acetone produces ____. a. ethanol b. 2-propanol c. 1-propanol d. propanal e. propene ANS: B OBJ: Identify the product of acetone reduction. TOP: Oxidation-Reduction Reactions 29. The oxidation of toluene by a basic solution of KMnO4 can be used in the production of ____. a.
b.
c.
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819
d.
e.
ANS: A OBJ: Identify the products given the reactants. TOP: Oxidation-Reduction Reactions 30. Which statement concerning the combustion of organic compounds is false? a. Combustion reactions of organic compounds are highly exothermic. b. The heat of combustion is the amount of energy liberated per mole of hydrocarbon burned. c. Aromatic hydrocarbons burn incompletely in air. d. The large amounts of heat produced by the combustion of hydrocarbons in an internal combustion engine expands the gases present in the engine, thereby driving the pistons and producing power. e. Incomplete combustion of hydrocarbons produces the poisonous gas CO. ANS: D OBJ: Identify the incorrect description of combustion. TOP: Oxidation-Reduction Reactions 31. The reaction of propionic acid with ____ produces propionyl chloride. a. sodium chloride b. hydrochloric acid c. hypochlorous acid d. chlorine e. phosphorus pentachloride ANS: E OBJ: Identify the missing reactant. TOP: Formation of Carboxylic Acid Derivatives 32. The reaction of propanoic acid with ethyl alcohol in the presence of sulfuric acid produces ____. a.
b.
c.
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820
d.
e.
ANS: A OBJ: Identify the products given the reactants. TOP: Formation of Carboxylic Acid Derivatives 33. What is the missing product for the following reaction?
a.
b.
c. CH3CH2ONH2 d. CH3CH2ON(CH3)2 e. CH3NHNHCH3 ANS: B OBJ: Identify the missing product structural formula. TOP: Formation of Carboxylic Acid Derivatives 34. The reaction of an acyl chloride with an amine to produce an amide requires 2 moles of amine per each mole of acyl chloride. Why? a. One mole of amine is required to buffer the solution. b. One mole of amine is required to make the solution basic. c. Each amide molecule contains 2 nitrogen atoms and therefore 2 amine molecules are required to supply the nitrogen. d. An excess of amine is required to shift the equilibrium toward the products. e. Half of the amine is used to convert to the amide and the other half reacts with the displaced hydrogen and chlorine to form an ammonium salt. ANS: E OBJ: Identify the correct explanation for the given reactant stoichiometry. TOP: Formation of Carboxylic Acid Derivatives 35. Which statement below concerning the given reaction is false?
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821
a. b. c. d. e.
The sodium salts of long-chain fatty acids are soaps. Strong reagents are required for the reactions of esters because esters are not very reactive. Esters are hydrolyzed by refluxing with solutions of strong bases. The hydrolysis of esters by strong bases is called saponification. The missing product in the equation above is R'H
ANS: E OBJ: Identify the incorrect description of the incomplete reaction given. TOP: Hydrolysis of Esters 36. What is the general formula for carbohydrates? a. (CH2O)n b. Cn(H2O)n+2 c. C(H2O)n d. Cn(H2O)m e. Cn(H2O)n+1 ANS: D OBJ: Identify the general formula of carbohydrates. TOP: Carbohydrates 37. Glucose is a monosaccharide that consists of a 6 carbon chain. The second, third, fourth and fifth carbons are each bonded to four different groups. Therefore glucose is ____. a. a ketose b. a glycogen c. chiral d. a polymer e. an oligosaccharide ANS: C OBJ: Recognize a description of chiral carbons. TOP: Carbohydrates 38. Which of the following statements about glucose is false? a. Glucose is a monosaccharide. b. Glucose is also commonly called dextrose or blood sugar. c. Glucose exists in two cyclic forms, called the and forms. d. Glucose has a ketone functional group. e. The and forms of glucose are stereoisomers. ANS: D OBJ: Identify the incorrect description of glucose. TOP: Carbohydrates 39. A disaccharide is formed when two monosaccharides are linked by the elimination of a molecule of water and the formation of an ether bond. The newly formed CO bond linking the monosaccharides is called the ____ bond. a. aldose b. ketose c. glycogen d. cyclic e. glycosidic
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ANS: E OBJ: Recognize the description of a glycosidic bond. TOP: Carbohydrates 40. Which statement concerning the twenty different -amino acids widely found in nature is true? a. Each -amino acid has a different number of carbon atoms. b. Each -amino acid has one amino (NH2) group. c. Each -amino acid has one carboxylic acid (COOH) group. d. These -amino acids differ in the R groups attached to the -carbon. e. None of these -amino acids are aromatic compounds. ANS: D OBJ: Identify the correct description of amino acids. TOP: Polypeptides and Proteins 41. The amino acids are usually classified by their R groups according to what two criteria? a. polarity and acidity-basicity b. polarity and ring-containing c. polarity and chirality d. acidity-basicity and chirality e. ring-containing and attachment to - or -carbon ANS: A OBJ: Identify how amino acids are classified according to their R groups. TOP: Polypeptides and Proteins 42. The functions of proteins do not include ____. a. enzymes b. hormones c. toxins d. sugars e. structural ANS: D OBJ: Identify the incorrect function of proteins. TOP: Polypeptides and Proteins 43. The order of the amino acids of a protein is termed the ____ structure. a. isomeric b. primary c. secondary d. tertiary e. quaternary ANS: B OBJ: Recognize the definition of protein primary structure. TOP: Polypeptides and Proteins 44. Nucleic acids are composed of what three different monomers? a. phosphate group / protein / selected organic base b. enzyme / protein / carbohydrate unit c. phosphate group / carbohydrate unit / selected organic base d. enzyme / hormone / selected organic acid e. protein / carbohydrate unit / selected organic acid Whitten 10e
Test Bank
823
ANS: C OBJ: Identify the monomers that make up nucleic acids. TOP: Nucleic Acids 45. Which statement about RNA and DNA is incorrect? a. The carbohydrates in nucleic acids are ribose in RNA and 2-deoxyribose in DNA. b. The bases adenine, guanine and cytosine are found in both RNA and DNA. c. The fourth base is uracil in RNA and thymine in DNA. d. In DNA adenine and thymine always pair by forming two hydrogen bonds. e. In both RNA and DNA, guanine and cytosine always pair by forming one hydrogen bond. ANS: E OBJ: Identify the incorrect description of RNA and DNA. TOP: Nucleic Acids 46. Which of the following polymers is composed of three different types of monomers? a. proteins b. nucleic acids c. Teflon d. rubber e. cellulose ANS: B OBJ: Identify the polymer made from three different monomers. TOP: Nucleic Acids 47. Approximately how many billion base pairs are there in human DNA? a. 1 b. 3 c. 4 d. 8 e. unknown ANS: B OBJ: Approximate the number of base pairs that make up human DNA. TOP: Nucleic Acids 48. How many structural (constitutional) isomers possessing the alcohol functional group have the molecular formula C3 H8 O? a. 3 b. 2 c. 1 d. 5 e. 4 ANS: B DIF: moderate OBJ: Determine the number of structural isomers given the formula. TOP: Constitutional Isomers
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824
49. When L-lysine (R = (CH2)4NH2) is reacted with a large excess of strong base, which of the following ions is the predominant species in solution? a.
b.
c.
d.
e.
ANS: A DIF: moderate OBJ: Identify the fully protonated or fully deprotonated form of an amino acid. TOP: Reactions of Brønsted-Lowry Acids and Bases
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825
50. Which of the following structures is the best representation for the amino acid serine under
physiological conditions? a.
b.
c.
d.
e.
ANS: C DIF: moderate OBJ: Identify the predominant form of an amino acid under physiological conditions. TOP: Polypeptides and Proteins 51. A fragment of a DNA molecule has the base sequence GACT. What is the complementary sequence? a. TACG b. TCAG c. CTAG d. CTGA e. GACT Whitten 10e
Test Bank
826
ANS: D DIF: easy OBJ: Determine the complimentary sequence of a DNA fragment. TOP: Nucleic Acids 52. Which of the following 2'-deoxynucleotides contains the base cytosine? a.
b.
c.
d.
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827
e.
ANS: E DIF: easy OBJ: Identify the DNA base . TOP: Nucleic Acids 53. What is the functional group classification of a compound with the general formula given below?
a. b. c. d. e.
ester primary amine secondary amine tertiary amine amide
ANS: A DIF: moderate OBJ: Identify the functional group. TOP: Polypeptides and Proteins 54. Which of the following would generally be considered a weak base? a. phenols b. substituted ammonium ions c. carboxylic acids d. alcohols e. none ANS: E DIF: moderate OBJ: Rank the functional groups according acidity or basicity. TOP: Reactions of Brønsted-Lowry Acids and Bases 55. Reduction of a ketone produces a(n) _____. a. alkane b. amide c. amine d. secondary alcohol e. primary alcohol
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ANS: D DIF: moderate OBJ: Predict the reduction product given the functional group. TOP: Oxidation-Reduction Reactions 56. A ketone may be produced by oxidation of a(n) _____. a. alkane b. alkene c. secondary alcohol d. primary alcohol e. ether ANS: C DIF: moderate OBJ: Predict the oxidation product given the functional group. TOP: Oxidation-Reduction Reactions 57. The side group of the following amino acid is classified as ____.
a. b. c. d. e.
polar and acidic polar and pH neutral polar and basic nonpolar nonpolar and acidic
ANS: B DIF: easy OBJ: Classify the amino acid side group. TOP: Amino Acids 58. Consider the following pair of molecules. Are these conformations of the same molecule,
constitutional isomers, cis-trans isomers, or different compounds?
a. conformers b. constitutional isomers
c. cis-trans isomers d. different compounds
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829
ANS: C OBJ: Identify the compounds as cis-trans isomers. TOP: Conformations 59. Consider the following pair of molecules. Are these conformations of the same molecule
(conformers), constitutional isomers, cis-trans isomers, or different compounds?
a. conformers b. constitutional isomers
c. cis-trans isomers d. different compounds
ANS: A OBJ: Identify the compounds as conformers. TOP: Conformations 60. Consider the following pair of molecules. Are these conformations of the same molecule,
constitutional isomers, cis-trans isomers, or different compounds?
a. conformers b. constitutional isomers
c. cis-trans isomers d. different compounds
ANS: B OBJ: Identify the compounds as constitutional isomers. TOP: Constitutional Isomers 61. Which of the following contains a stereocenter (asymmetric carbon)? a. 2-ethyl-1-butanol b. 2-methyl-2-pentanol c. 2,3-dimethylpentane d. 2,2-dimethylpropane e. None of the above ANS: C OBJ: Identify the molecule with an asymmetric carbon. TOP: Chirality Whitten 10e
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830
62. Which of the following contains a stereocenter (asymmetric carbon)? a.
b.
c.
d. e. None of the above ANS: A OBJ: Identify the molecule with an asymmetric carbon. TOP: Chirality 63. Which of the following represents a constitutional isomer of the molecule shown below:
a. b. c. d. e.
ANS: B OBJ: Identify the constitutional isomer. TOP: Constitutional Isomers 64. Which of the following represents a constitutional isomer of the molecule shown below: a. b.
c.
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831
d.
e.
ANS: B OBJ: Identify the constitutional isomer. TOP: Constitutional Isomers CONCEPTUAL 1. Compare natural and synthetic polymers. What are some similarities and differences in them? OBJ: Compare and contrast natural and synthetic polymers. TOP: Polymers 2. Fats, carbohydrates and proteins make up our dietary intake. Explain what happens in the initial stages of digestion, when these are broken down into fatty acids, monosaccharides and amino acids. OBJ: Describe the chemical reactions that occur on digestion of fats, carbohydrates, and proteins. TOP: Reactions of Fats, Carbohydrates, and Proteins 3. The staggered and eclipsed forms of butane both exist at room temperature as the molecule rotates about a single bond. Explain what would happen if the temperature dropped to 25 K. OBJ: Explain the effect of low temperatures on a molecule that exhibits free single bond rotation at room temperature. TOP: Conformations 4. Explain the fact that carboxylic acids, esters and amides are commonly found in nature, whereas acyl halides are not. OBJ: Explain the fact that acyl halides are not commonly found in nature. TOP: Formation of Carboxylic Acid Derivatives 5. All hydrocarbons undergo combustion reactions. Why does octane have a higher heat of combustion than pentane? OBJ: Explain the greater heat of combustion for octane compared to pentane. TOP: Oxidation-Reduction Reactions 6. Which letters of the alphabet are chiral? Which are achiral? OBJ: Identify the letters in the alphabet that are chiral and achiral. TOP: Chirality
Chapter 25—Coordination Compounds MULTIPLE CHOICE
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1. Alfred Werner isolated the platinum(IV) compounds, PtCl4nNH3 (n = 2 to 6). He added excess AgNO3 to solutions of each and determined the moles of AgCl precipitated. He also measured and compared the conductances of solutions of each of these compounds with solutions of simple electrolytes. Which response below gives all true statements concerning his conclusions from these experiments? I. From the moles of AgCl, he determined the total number of Cl ions in each compound. II. From the moles of AgCl, he determined the number of uncoordinated Cl ions in each compound. III. From the conductance of each solution, he determined the total number of ions present upon dissolution of each compound. a. b. c. d. e.
I II III I and II II and III
ANS: E OBJ: Identify the conclusions consistent with the experimental work. TOP: Coordination Compounds 2. A Lewis base makes available an electron pair to be shared to form a(n) ____ bond. a. ionic b. radical c. coordinate covalent d. hydrogen e. basic ANS: C OBJ: Complete the definition of Lewis base. TOP: Coordination Compounds 3. A Lewis acid accepts a share in an electron pair to form a(n) ____ bond. a. hydrogen b. cationic c. anionic d. pi e. coordinate covalent ANS: E OBJ: Complete the definition of a Lewis acid. TOP: Coordination Compounds
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4. Most transition metals have vacant ____ orbitals that can accept shares in electron pairs; thus they can act as Lewis ____. a. d; bases b. p; acids c. s; bases d. p; bases e. d; acids ANS: E OBJ: Complete the description of transition metal electron structure and Lewis acid-base character. TOP: Coordination Compounds 5. When tin(IV) chloride forms coordinate covalent bonds with two chloride ions, what is the formula and the charge of the resulting coordination compound? a. [SnCl4]2 b. [SnCl6]4+ c. [SnCl4]2+ d. [SnCl6]2 e. [SnCl3]2 ANS: D OBJ: Identify the resulting coordination compound given the reactants. TOP: Coordination Compounds 6. When tin(VI) chloride forms coordinate covalent bonds with two chloride ions, which statement below is correct about the resulting bonds? a. The two coordinate covalent bonds are different from the other bonds. b. All four of the bonds in the coordination compound are identical. c. All six of the bonds in the coordination compound are identical. d. The coordinate covalent bonds form because the chloride ions act as Lewis acids. e. None of these is correct. ANS: C OBJ: Identify the correct description of bonding in a coordination compound. TOP: Coordination Compounds 7. In which one of the following is the oxidation state of the underlined metal incorrect?
a. b. c. d. e.
Complex Ion [Mn(en)2(F)(I)]NO3 [Pt(NH3)2(Cl)2]Cl2 K3[Co(NO2)6 K3[Fe(CN)6] [Cr(en)3]2(SO4)3
Oxidation State of Underlined Metal +3 +2 +3 +3 +3
ANS: B OBJ: Identify the incorrectly assigned oxidation state. TOP: Coordination Compounds
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8. In which one of the following is the oxidation state of the underlined metal incorrect?
a. b. c. d. e.
Complex Species Oxidation State of Underlined Metal [Cr(OH2)3Br3] +3 [Co(OH2)6](NO3)2 +2 [Co(NH3)2(en)(Cl)2]2SO4 +1 [Fe(CO)5] 0 [Cr(NH3)6]2[NiCl4]3 +2
ANS: C OBJ: Identify the incorrectly assigned oxidation state. TOP: Coordination Compounds 9. In which one of the following is the oxidation number of the transition metal incorrect?
a. b. c. d. e.
Complex Species Oxidation Number of Transition Metal [Cr(CO)6]Cl3 +3 [Cu(OH)4(NH3)2] +4 K4[Mn(CN)6] +3 [Pt(en)3](NO3)4 +4 [Pt(NH3)2(OH2)Cl]3PO4 +2
ANS: C OBJ: Identify the incorrectly assigned oxidation state. TOP: Coordination Compounds 10. Which one of the following ions forms a soluble complex in the presence of excess of aqueous ammonia? a. Al3+ b. Cu2+ c. Pb2+ d. Be2+ e. Fe2+ ANS: B OBJ: Identify the ion that forms a soluble complex in ammonia. TOP: The Ammine Complexes 11. Which one of the following ions does not form a soluble complex in the presence of excess aqueous ammonia? a. Zn2+ b. Ni2+ c. Mn2+ d. Co2+ e. Ag+ ANS: C OBJ: Identify the ion that does not form a soluble complex in ammonia. TOP: The Ammine Complexes
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12. The number of donor atoms to which an acceptor metal ion is bonded in a complex species is called the ____ number of the metal ion. a. oxidation b. ligand c. coordination d. donor e. chelating ANS: C OBJ: Complete the definition of coordination number. TOP: Important Terms 13. The ____ sphere is enclosed in brackets in formulas for complex species, and it includes the central metal ion plus the coordinated groups. a. ligand b. donor c. oxidation d. coordination e. chelating ANS: D OBJ: Complete the definition of coordination sphere. TOP: Important Terms 14. Complexes that consist of a metal atom or ion and polydentate ligands are called ____. a. coordination spheres b. chelate complexes c. ligand complexes d. ligand spheres e. none of these ANS: B OBJ: Complete the definition of chelate complexes. TOP: Important Terms 15. Which of the following ligands is a polydentate ligand? a. ethylenediamine b. ammonia c. cyanide d. water e. nitrite ANS: A OBJ: Identify the polydentate ligand. TOP: Nomenclature 16. Which of the following ligands is a monodentate ligand? a. ethylenediamine b. oxalate c. diethylenetriamine d. ammonia e. ethylenediaminetetraacetate
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ANS: D DIF: Harder Question OBJ: Identify the monodentate ligand. TOP: Nomenclature 17. Which answer below lists the incorrect number of donor atoms for the given ligand? a. ethylenediamine / 2 b. carbon monoxide / 1 c. cyanide / 1 d. nitrite / 1 e. ethylenediaminetetraacetate / 4 ANS: C OBJ: Identify the incorrectly number of donor atoms and ligand. TOP: Nomenclature 18. Which ligand formula is incorrectly matched with its name as a ligand?
a. b. c. d. e.
Ligand / Name SO42 / sulfato CO32 / carbonato S2O32 / sulfato F / fluoro O2 / oxo
ANS: C OBJ: Identify the incorrectly matched ligand name and formula. TOP: Nomenclature 19. Which ligand formula is incorrectly matched with its name as a ligand?
a. b. c. d. e.
Ligand / Name NH3 / ammine PH3 / phosphine NO / nitro OH / hydroxo Br / bromo
ANS: C OBJ: Identify the incorrectly matched ligand name and formula. TOP: Nomenclature 20. Below is a list of formulas for complex compounds; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Co(en)2Br2]Br / dibromobis(ethylenediamine)cobalt(III) bromide [Fe(NH3)5(OH2)]Cl3 / pentaammineaquairon(III) chloride K3[Co(NO2)6] / potassium hexanitrocobaltate(III) [Cr(NH3)3(OH)3] / triamminetrihydroxochromate(III) [Ni(en)3](NO3)2 / tris(ethylenediamine)nickel(II) nitrate
ANS: D OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature Whitten 10e
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837
21. Below is a list of formulas for complex compounds and ions; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Co(NH3)4(OH2)(I)]SO4 / tetraammineaquaiodocobalt(III) sulfate K[Cr(NH3)2Cl4] / potassium diamminetetrachlorochromate(III) [Mn(CN)5]2 / pentacyanomanganate(II) ion [Ni(CO)4] / tetracarbonylnickel(0) Ca[PtCl4] / calcium tetrachloroplatinate(II)
ANS: C OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature 22. Below is a list of formulas for complex compounds; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name K3[Fe(CN)6] / potassium hexacyanoferrate(III) Na[CuCl3] / sodium trichlorocuprate(II) Na3[Co(CO3)3] / sodium tricarbonatocobaltate(III) [CoClBr(NH3)4]I / tetraamminebromochlorocobalt(II) iodide Rb3[FeF6] / rubidium hexafluoroferrate(III)
ANS: D OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature 23. Below is a list of formulas for complex compounds; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Cr(NH3)3(OH)3] / triamminetrihydroxochromium(VI) K3[FeF6] / potassium hexafluoroferrate(III) Na[Cu(CN)2] / sodium dicyanocuprate(I) [Co(en)3](NO3)3 / tris(ethylenediamine)cobalt(III) nitrate Na2[SnCl6] / sodium hexachlorostannate(IV)
ANS: A OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature 24. Below is a list of formulas for complex compounds and ions; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Co(NH3)6][Co(CN)6] / hexaamminecobalt(III) hexacyanocobaltate(III) Ca3[Fe(C2O4)3]2 / calcium tris(oxalato)ferrate(III) [Co(en)3]3(SO4)2 / tris(ethylenediamine)cobalt(III) sulfate [Pt(NH3)4Cl2]2+ / tetraamminedichloroplatinum(IV) ion K[Cr(NH3)2Cl4] / potassium diamminetetrachlorochromate(III)
ANS: C OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature Whitten 10e
Test Bank
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25. Below is a list of formulas for complex compounds and ions; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Pt(en)3](NO3)4 / tris(ethylenediamine)platinum(IV) nitrate [Ni(CO)2(NH3)2] / diamminedicarbonylnickel(II) K2[SnF6] / potassium hexafluorostannate(IV) Ca[PdCl6] / calcium hexachloropalladate(IV) [Co(NO)4Cl2]3PO4 / dichlorotetranitrosylcobalt(III) phosphate
ANS: B OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature 26. Below is a list of formulas for complex compounds and ions; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Ru(H2O)6]3+ / hexaaquaruthenium(III) ion [Co(NH3)3(H2O)2Cl]2SO4 / triamminediaquachlorocobalt(II) sulfate Na2[Sn(CN)5(OH)] / sodium hydroxopentacyanostannate(IV) [Sn(C2O4)3]2 / tris(oxalato)stannate(IV) ion Ca[Co(edta)]2 / calcium (ethylenediaminetetraacetato)cobaltate(III)
ANS: C OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature 27. Below is a list of formulas for complex compounds and ions; each is matched with its name. One formula / name combination contains an error. Which one?
a. b. c. d. e.
Formula / Name [Ag(NH3)2]NO3 / diamminesilver(I) nitrate [Fe(CN)6]3 / hexacyanoiron(III) ion [Cr(OH2)6]2(SO4)3 / hexaaquachromium(III) sulfate Na2[Ni(CN)4] / sodium tetracyanonickelate(II) Li[AgI2] / lithium diiodoargentate(I)
ANS: B OBJ: Identify the incorrectly matched compound name and formula. TOP: Nomenclature 28. Which idealized geometry is not matched correctly with the given coordination number?
a. b. c. d. e.
Coordination number / Idealized Geometry 2 / linear 4 / tetrahedral 5 / square pyramidal 6 / trigonal bipyramidal 4 / square planar
ANS: D OBJ: Identify the incorrectly matched coordination number and geometry. TOP: Structures
Whitten 10e
Test Bank
839
29. Below is a list of complex ions and their structures. One pair is incorrectly matched. Which pair?
a. b. c. d. e.
Complex Ion / Structure [Zn(NH3)4]2+ / tetrahedral [CoF6]4 / octahedral [Cu(NH3)4]2+ / square planar [Cu(CN)2] / angular [Ni(OH2)6]2+ / octahedral
ANS: D OBJ: Identify the incorrectly matched coordination compound formula and geometry. TOP: Structures 30. Below is a list of complex ions and their structures. One pair is incorrectly matched. Which pair?
a. b. c. d. e.
Complex Ion / Structure [Fe(CN)6]3 / octahedral [PtCl6]2 / octahedral [PtCl4]2 / square planar [Zn(OH)4]2 / tetrahedral [Co(en)2(Cl)2]+ / distorted tetrahedral
ANS: E OBJ: Identify the incorrectly matched coordination compound formula and geometry. TOP: Structures 31. Which shape is not commonly observed in coordination compounds? a. octahedral b. trigonal planar c. square planar d. trigonal bipyramid e. tetrahedral ANS: B OBJ: Identify the rare coordination compound geometry. TOP: Structures 32. Below is a list of complex species and their structures. One pair is incorrectly matched. Which pair?
a. b. c. d. e.
Complex Species / Structure [Fe(CO)5] / trigonal bipyramidal [Cr(OH2)6]3+ / octahedral [Ni(CN)4]2 / square planar [CdBr4]2 / square pyramidal [Cu(NH3)4]2+ / square planar
ANS: D OBJ: Identify the incorrectly matched coordination compound formula and geometry. TOP: Structures
Whitten 10e
Test Bank
840
33. Below is a list of complex species and their structures. One pair is incorrectly matched. Which pair?
a. b. c. d. e.
Complex Species / Structure [Cd(NH3)4]2+ / tetrahedral [Co(NH3)6]3+ / octahedral [Ag(NH3)2]+ / linear [Cu(NH3)4]2+ / square planar [Hg(NH3)4]2+ / trigonal bipyramid
ANS: E OBJ: Identify the incorrectly matched coordination compound formula and geometry. TOP: Structures 34. Below is a list of complex ions and their structures. One pair is incorrectly matched. Which pair?
a. b. c. d. e.
Complex Ion / Structure [MnCl5]3 / trigonal planar [CuBr2] / linear [Pt(NH3)2Cl2] / square planar [Cu(NH3)4]2+ / square planar [Cr(CO)6]2+ / octahedral
ANS: A OBJ: Identify the incorrectly matched coordination compound formula and geometry. TOP: Structures 35. Below is a list of complex ions and their structures. One pair is incorrectly matched. Which pair?
a. b. c. d. e.
Complex Ion / Structure [CoCl6]3 / trigonal bipyramidal [Cd(NH3)4]2+ / tetrahedral [NiCl4]2 / tetrahedral [Au(CN)2] / linear [Co(CN)6]3 / octahedral
ANS: A OBJ: Identify the incorrectly matched coordination compound formula and geometry. TOP: Structures 36. Which of the following is not a type of structural (constitutional) isomer? a. ionization b. linkage c. hydrate d. geometric e. coordination ANS: D OBJ: Identify the term that is not a type of structural isomer. TOP: Structural (Constitutional) Isomers
Whitten 10e
Test Bank
841
37. Which of the following pairs of complex compounds are not ionization isomers? a. [Pt(NH3)4Cl2]Br2 and [Pt(NH3)4Br2]I2 b. [Co(NH3)5NO2]SO4 and [Co(NH3)5SO4]NO2 c. [Cr(NH3)5SO4]Br and [Cr(NH3)5Br]SO4 d. [Co(NH3)5Br]SO4 and [Co(NH3)5SO4]Br e. [Pt(NH3)4Br2]Cl2 and [Pt(NH3)4Cl2]Br2 ANS: A OBJ: Identify the pair of coordination compound formulas that are not ionization isomers. TOP: Structural (Constitutional) Isomers 38. The following are examples of what kind of isomers? [Co(NH3)4(OH2)Cl]Cl2 and [Co(NH3)4Cl2]ClH2O a. b. c. d. e.
linkage optical coordination ionization hydrate
ANS: E OBJ: Classify the structural isomers. TOP: Structural (Constitutional) Isomers 39. The following are examples of what kind of isomers? [Co(NH3)4Cl2][Cr(NH3)2(CN)4] and [Cr(NH3)4(CN)2][Co(NH3)2(CN)2Cl2] a. b. c. d. e.
linkage optical hydrate ionization coordination
ANS: E OBJ: Classify the structural isomers. TOP: Structural (Constitutional) Isomers 40. Which of the following is the ionization isomer of [Pt(NH3)4Br2](NO3)2? a. [Co(NH3)4Br2](NO3)2 b. [Pt(NH3)4 (NO3)2]Br2 c. [Pt(NH3)6](NO3)2 d. [Pt(NO3)4Br2](NH3)2 e. [Pt(NO3)4 (NH3)2]Br2 ANS: B OBJ: Identify the ionization isomer of the given compound. TOP: Structural (Constitutional) Isomers
Whitten 10e
Test Bank
842
41. Two complex ions consisting of a Co3+ ion, 5 NH3 ligands, and a CN ligand can exist. For one of these complex ions, the C of the CN ligand acts as the donor atom; and for the other complex ion, the N of the CN ligand acts as the donor atom. What kind of isomers are these two complex ions? a. geometric b. optical c. linkage d. ionization e. coordination ANS: C OBJ: Classify the structural isomers. TOP: Structural (Constitutional) Isomers 42. Which of the following is not the name (as a ligand) for a ligand that can bind to metal ions in more than one way; that is, using two different donor atoms? a. cyano b. nitro c. isocyano d. aqua e. nitrito ANS: D OBJ: Identify the ligand that is not ambidentate. TOP: Structural (Constitutional) Isomers 43. The following square-planar complexes are what kind of isomers?
a. b. c. d. e.
linkage coordination ionization optical geometric
ANS: E OBJ: Classify the stereoisomers. TOP: Stereoisomers 44. Which response includes all of the following statements about the neutral square-planar complexes shown below that are true and no false statements?
Whitten 10e
Test Bank
843
I. II. III. IV. V. a. b. c. d. e.
The compounds are optical isomers. The isomer on the left is the trans isomer. The isomer on the left is the cis isomer. The isomers are nonsuperimposable mirror images. The isomers have different properties. I, IV, and V II and V I, III, and IV I, II, and IV III and V
ANS: B OBJ: Identify the correction descriptions of the stereoisomers. TOP: Stereoisomers 45. Which of the below structures are identical?
a. b. c. d. e.
IV and V V and VI IV and VI II and IV none of these are identical
Whitten 10e
Test Bank
844
ANS: C OBJ: Identify the identical stereoisomers. TOP: Stereoisomers 46. The following complex ions are what kind of isomers? (M = metal; A, B, C and D = ligands)
a. b. c. d. e.
ionization geometric coordination optical linkage
ANS: D OBJ: Classify the stereoisomers. TOP: Stereoisomers 47. Which of the structures below has each of the three pairs of like ligands in the cis position to each other?
a. b. c. d. e.
I II III IV none of these do
ANS: E OBJ: Identify the all cis configuration. TOP: Stereoisomers Whitten 10e
Test Bank
845
48. What is a general formula for octahedral complexes that exhibit mer - fac isomerism? (M = metal; A, B and C = ligands) a. MA5B b. MA4B2 c. MA3B3 d. MA2B2 e. MA2B2C2 ANS: C OBJ: Identify the general formula for a compound that can exhibit mer-fac isomerism. TOP: Stereoisomers 49. Which of the structures below has each of the three pairs of like ligands in the trans position to each other?
a. b. c. d. e.
I II III II and III IV
ANS: A OBJ: Identify the all trans configuration. TOP: Stereoisomers
Whitten 10e
Test Bank
846
50. Which of the structures below are optical isomers?
a. b. c. d. e.
V and VI II and III I and IV I and III none of these are optical isomers
ANS: A OBJ: Identify the optical isomers. TOP: Stereoisomers 51. For which of the following are cis-trans isomers the only kind of isomers that can exist? a. [Co(NH3)5Br]2+ b. [Co(NH3)4Cl2]+ c. [Co(NH3)2(OH2)Cl2]+ d. [Co(en)3]3+ e. [Co(NH3)6]3+ ANS: B OBJ: Identify the formula of a compound with only cis-trans isomerism possible. TOP: Stereoisomers
Whitten 10e
Test Bank
847
52. Which of the following statements concerning the tris(ethylenediamine)cobalt(III) ion, [Co(en)3]3+, is false? a. Each bidentate ethylenediamine ligand bonds in cis positions. b. The [Co(en)3]3+ exists in the form of a pair of nonsuperimposable mirror images. c. The coordination number of the Co metal ion is 3. d. The [Co(en)3]3+ exists as a pair of optical isomers. e. The two optical isomers each rotate a plane of polarized light by equal amounts but in opposite directions. ANS: C OBJ: Identify the incorrect description of the coordination compound. TOP: Stereoisomers 53. Consider the following statements about optical isomers. Which statement is true? a. Optical isomers do not react with polarized light. b. Dextrorotary implies that light is rotated to the left. c. A solution with equal amounts of two optical isomers is called a racemic mixture. d. Racemic mixtures react with polarized light. e. All of these are true. ANS: C OBJ: Identify the incorrect description of optical isomers. TOP: Stereoisomers 54. The crystal field splitting energy is proportional to the ____ of the ligands, which is defined as how strongly the ligand electrons repel the electrons on the metal ion. a. oct b. electron pairing energy c. t2g orbitals d. crystal field strength e. eg orbitals ANS: D OBJ: Identify the description of crystal field splitting energy. TOP: Crystal Field Theory 55. Which of the following statements is true? a. All five d orbitals increase their energy levels the same amount for a metal surrounded by ligands in an octahedral crystal field. b. Because the ligands approach the metal ion from different directions, they affect different d orbitals in different ways. c. There are 3 eg orbitals. d. The t2g orbitals are higher in energy than the eg orbitals. e. oct is proportional to the crystal field strength of the metal ion. ANS: B OBJ: Identify the correct description of crystal field theory. TOP: Crystal Field Theory 56. The total number of electrons in the 3d orbitals of Co3+ is ____. a. 6 b. 7 c. 3 d. 4 e. 5 Whitten 10e
Test Bank
848
ANS: A OBJ: Identify the total number of d electrons in an ion. TOP: Crystal Field Theory 57. In which one of the following does the transition metal have a 3d6 electronic configuration? a. [Cr(OH2)6]3+ b. [Fe(CN)6]3 c. [Fe(CN)6]4 d. [Ni(NH3)6]2+ e. [Zn(NH3)4]2+ ANS: C OBJ: Identify the coordination compound in which the metal has the specified configuration. TOP: Crystal Field Theory 58. In which one of the following does the transition metal have a 3d8 electronic configuration? a. [Fe(NCS)(OH2)5]2+ b. [FeF6]4 c. [CuCl4]2 d. [Co(NH3)6]3+ e. [Ni(NH3)6]2+ ANS: E OBJ: Identify the coordination compound in which the metal has the specified configuration. TOP: Crystal Field Theory 59. In which one of the following does the transition metal have a 3d9 electronic configuration? a. [Zn(NH3)4]2+ b. [Co(OH2)6]2+ c. [Co2(CO)8] d. [Fe(CO)5] e. [Cu(NH)4]2+ ANS: E OBJ: Identify the coordination compound in which the metal has the specified configuration. TOP: Crystal Field Theory 60. For which one of the following octahedral configurations is a low spin configuration possible? a. d3 b. d9 c. d8 d. d5 e. d2 ANS: D OBJ: Identify the d-electron count possible for an octahedral compound with a low spin configuration. TOP: Crystal Field Theory 61. Which one of the following octahedral configurations has no low spin configuration? a. d4 b. d7 c. d8 d. d6 e. d5 Whitten 10e
Test Bank
849
ANS: C OBJ: Identify the d-electron count for which an octahedral compound has no low spin configuration. TOP: Crystal Field Theory 62. How many unpaired electrons would you expect for each formula unit of [V(CN)6]3? a. 1 b. 2 c. 3 d. 4 e. 5 ANS: B OBJ: Determine the number of unpaired electrons given the formula. TOP: Crystal Field Theory 63. How many unpaired electrons does one formula unit of [MnF6]3 contain? a. 1 b. 2 c. 3 d. 4 e. 5 ANS: D OBJ: Determine the number of unpaired electrons given the formula. TOP: Crystal Field Theory 64. How many unpaired electrons does one formula unit of [Pd(NO2)6]2 contain? a. 0 b. 1 c. 2 d. 3 e. 4 ANS: A OBJ: Determine the number of unpaired electrons given the formula. TOP: Crystal Field Theory 65. Which one of the following statements is false? a. Paramagnetic metal ions must have an odd number of electrons. b. Diamagnetic metal ions cannot have an odd number of electrons. c. Low spin complexes can be paramagnetic. d. In high spin octahedral complexes, is less than the electron pairing energy. e. Low spin complexes contain strong field ligands. ANS: A OBJ: Identify the incorrect description of magnetism and crystal field theory. TOP: Crystal Field Theory 66. Consider the complex ion [Co(NH3)6]3+. Which response contains all of the following statements that are true, and no false statements? I. It is paramagnetic. II. It is a high spin complex. III. It is a low spin complex. IV. It has octahedral geometry. V. It does not exist as geometric isomers. Whitten 10e
Test Bank
850
a. b. c. d. e.
I and II III and IV II, IV, and V III, IV, and V I and IV
ANS: D OBJ: Identify the correct descriptions of a coordination compound. TOP: Crystal Field Theory 67. Consider the complex ion [CoCl6]4. Which response contains all of the following statements that are true, and no false statements? I. The complex is a d7 complex. II. The Co has two unpaired electrons. III. It is paramagnetic. IV. It is a low spin complex. V. It has tetrahedral geometry. VI. It is a high spin complex. a. b. c. d. e.
II, IV, and V I, III, and V II, V, and VI III, V, and VI I, III, and VI
ANS: E OBJ: Identify the correct descriptions of a coordination compound. TOP: Crystal Field Theory 68. Consider the complex ion [FeF6]3. Which response includes all of the following statements that are true, and no false statements? I. It is paramagnetic. II. It is a low spin complex. III. It is a high spin complex. IV. The oxidation number of iron is +3. a. b. c. d. e.
I, III, and IV II and III IV I and II II and IV
ANS: A OBJ: Identify the correct descriptions of a coordination compound. TOP: Crystal Field Theory 69. Consider the complex ion [Cr(CN)6]3. Which response includes all of the following statements that are true, and no others? I. It is diamagnetic. II. The chromium has three unpaired electrons. III. It is a high spin complex. IV. The oxidation number of chromium is 3.
Whitten 10e
Test Bank
851
a. b. c. d. e.
III and IV I and IV II and III I, II, and III I, II, and IV
ANS: C OBJ: Identify the correct descriptions of a coordination compound. TOP: Crystal Field Theory 70. Consider the complex ion [Mn(OH2)6]2+. Which response includes all of the following statements that are true, and no false statements? I. It is diamagnetic. II. It is a low spin complex. III. It is a high spin complex. IV. The ligands are weak field ligands. V. The manganese has 5 unpaired electrons. a. b. c. d. e.
I, II and V III, IV, and V I, II and IV II and V III and IV
ANS: B DIF: Harder Question OBJ: Identify the correct descriptions of a coordination compound. TOP: Crystal Field Theory 71. Consider the complex ion [Fe(CN)6]4. Which of the following responses includes all of the true statements with respect to this complex ion and the ions from which it was formed, and no false statements? I. The complex ion is octahedral. II. Fe2+ is a d5 ion. III. CN is a strong field ligand. IV. CN is a weak field ligand. V. The complex ion is a low spin complex. VI. The complex ion is a high spin complex. VII. The complex ion contains no unpaired electrons. VIII. The complex ion contains four unpaired electrons. a. b. c. d. e.
I, II, III, V, and VII II, III, V, and VII II, IV, VI, and VIII I, II, IV, VI, and VIII I, III, V, and VII
ANS: E DIF: Harder Question OBJ: Identify the correct descriptions of a coordination compound. TOP: Crystal Field Theory
Whitten 10e
Test Bank
852
72. The nitrate of which one of the following cations would be colored in aqueous solutions? a. Al3+ b. Ca2+ c. Na+ d. Cr3+ e. Pb2+ ANS: D OBJ: Identify the colored ion. TOP: Color and the Spectrochemical Series 73. Which one of the following is always a strong field ligand? a. Br b. H2O c. F d. CN e. Cl ANS: D OBJ: Identify the strong field ligand. TOP: Color and the Spectrochemical Series 74. Which of the following statements concerning octahedral complexes is incorrect? a. Strong field ligands produce large crystal field splittings. b. Weak field ligands produce high spin complexes. c. Halide ions are strong field ligands. d. Weak field ligands result in relatively small values for . e. A relatively large value for causes a complex ion to absorb relatively high energy (shorter wavelength) light. ANS: C OBJ: Identify the incorrect description of crystal field theory. TOP: Color and the Spectrochemical Series
Dynamic Questions 75. What is the formula for the hexaaquatitanium(II) ion? a. [Ti(H2O)6]2+ b. [Ti(H2O)4]2+ c. [Ti2(H2O)6]4– d. [Ti2(H2O)6]2+ e. [Ti2(H2O)6]4+ ANS: A DIF: easy OBJ: Identify the formula of a coordination compound given the systematic name. TOP: Nomenclature 76. What is the formula for the pentaamminehydroxovanadium(II) ion? a. [V(NH3)5(OH)5]2+ b. [V(NH3)5(OH)5]3– c. [V(NH3)5(OH)]2+ d. [V(NH3)5(OH)]+ e. [V(NH3)(OH)5]3– Whitten 10e
Test Bank
853
ANS: D DIF: easy OBJ: Identify the formula of a coordination compound given the systematic name. TOP: Nomenclature 77. Which complex is capable of forming geometric isomers? a. K3[FeCl6] b. [Co(NH3)5Br]Br2 c. [Co(NH3)6]Br3 d. [Pd(NH3)2Br2] e. [Pt(NH3)4]Br2 ANS: D DIF: easy OBJ: Identify the compound that can form geometrical isomers. TOP: Structural (Constitutional) Isomers 78. If an octahedral iron(II) complex is paramagnetic, which of the following sets of conditions best describes the complex? a. b. c. d. e.
low spin, oct small low spin, oct large high spin, oct small high spin, oct large none of the above
ANS: C DIF: easy OBJ: Describe the octahedral electron configuration given a compounds magnetic information.. TOP: Crystal Field Theory 79. Which of the following salts would not be expected to be colored in aqueous solution? Assume all compounds form octahedral coordination compounds on dissolution. a. NiCl2 b. CuCl2 c. MnCl2 d. TiCl3 e. HgCl2 ANS: E DIF: easy OBJ: Identify the compound in which d-d electron transitions are not possible. TOP: Color and the Spectrochemical Series
Whitten 10e
Test Bank
854
80. What is the denticity of the pictured ligand?
ethylenediamine (en) a. b. c. d. e.
1 4 3 2 5
ANS: D DIF: moderate OBJ: Determine the denticity of the pictured ligand. TOP: Nomenclature 81. What is the coordination number of Co in the coordination compound [Co(en)3]?
ethylenediamine (en) =
a. b. c. d. e.
2 3 4 6 5
ANS: D DIF: moderate OBJ: Determine the coordination number of the metal given the coordination complex formula. TOP: Nomenclature 82. Which of the following will not form a coordination complex with a transition metal ion? a. NO b. H3O+ c. NH3 d. CN e. NO
Whitten 10e
Test Bank
855
ANS: B DIF: moderate OBJ: Identify the species that will not form a coordination complex. TOP: Coordination Compounds 83. What is the coordination number of the transition metal ion in [Ni(NH3)6]Cl2? a. 6 b. 2 c. 4 d. 3 e. 5 ANS: A DIF: moderate OBJ: Determine the coordination number of the metal given the coordination complex formula. TOP: Coordination Compounds 84. What are the possible geometries of a metal complex with a coordination number of 6? 1. square planar 2. tetrahedral 3. octahedral a. b. c. d. e.
1 only 2 only 3 only 1 and 2 1, 2, and 3
ANS: C OBJ: Match the possible geometries with the coordination number. TOP: Coordination Compounds 85. Which of the following statements describes the relationship of the two drawings below?
a. b. c. d.
cis-trans isomerism optical isomerism fac-mer isomerism different representations of the same species
ANS: D OBJ: Identify the conformers. TOP: Coordination Compounds
Whitten 10e
Test Bank
856
86. Which of the following statements describes the relationship of the two drawings below?
a. b. c. d.
cis-trans isomerism optical isomerism fac-mer isomerism different representations of the same species
ANS: C OBJ: Identify the fac-mer isomers. TOP: Stereoisomers 87. Which of the following statements describes the relationship of the two drawings below?
a. b. c. d.
ionization isomerism stereoisomerism linkage isomerism different representations of the same species
ANS: A OBJ: Identify the ionization isomers. TOP: Structural (Constitutional) Isomers 88. Which of the following statements describes the relationship of the two drawings below?
a. b. c. d.
ionization isomerism stereoisomerism linkage isomerism different representations of the same species
ANS: C OBJ: Identify the linkage isomers. TOP: Coordination Compounds
Whitten 10e
Test Bank
857
CONCEPTUAL 1. Hemoglobin is red in the presence of oxygen. Explain what happens to the hemoglobin of someone who has been exposed to carbon monoxide, knowing that CO has 200-times greater affinity for hemoglobin than oxygen. OBJ: Compare the hemoglobin complexes of oxygen and carbon monoxide. TOP: Crystal Field Theory | Color and the Spectrochemical Series 2. Compare paramagnetic, diamagnetic and ferromagnetic. When do you expect each to happen? OBJ: Define and give examples of the terms paramagnetic, diamagnetic, and ferromagnetic. TOP: Magnetism | Crystal Field Theory 3. Explain why heavy metal poisoning cases are treated with complexing agents (ligands) to form complex ions with the ingested metals. How is this an effective treatment? OBJ: Explain why chelation therapy is effective. TOP: Coordination Compounds | Formation Constants 4. What are the major differences in structural isomers compared to stereoisomers? Can all metals experience both types of isomerism? OBJ: Contrast stereo- and structural isomerism. TOP: Structural (Constitutional) Isomers | Stereoisomers 5. Why can't valence bond theory account for the color of compounds? OBJ: Explain why VBT cannot account for compound color. TOP: Valence Bond Theory
Chapter 26—Metals I: Metallurgy MULTIPLE CHOICE 1. Which of the following metallic elements is not present in substantial quantities in a healthy human body? a. sodium b. potassium c. lead d. calcium e. magnesium ANS: C OBJ: Identify the metal not found in a healthy human. TOP: Occurrence of the Metals 2. Which of the following is not characteristic of metals? a. conductors of heat and electricity b. form covalent bonds with nonmetals c. almost all are solids d. outer shells contain few electrons e. used structurally in buildings, cars, and ships Whitten 10e
Test Bank
858
ANS: B OBJ: Identify the description not characteristic of a metal. TOP: Occurrence of the Metals 3. Four of the following occur as native ores. One does not. Which one? a. Ag b. Au c. Pt d. Cu e. Al ANS: E OBJ: Identify the element that does not occur as a native ore. TOP: Occurrence of the Metals 4. Which of the following terms and descriptions are incorrectly matched? a. native ore / ore found in one's country of birth b. metallurgy / extraction of metal from their ores c. ore / rocks consisting of metal-containing compounds d. gangue / sand, soil, clay, and rock e. minerals / comparatively pure compounds containing metals found in ore ANS: A OBJ: Identify the incorrect definition of a terms related to metallurgy. TOP: Occurrence of the Metals
Whitten 10e
Test Bank
859
5. Which one of the following ores is a sulfide ore? a. kaolinite b. magnesite c. galena d. magnetite e. bauxite ANS: C OBJ: Identify the sulfide ore. TOP: Occurrence of the Metals 6. Which ore of the following pairs of minerals and ores do not match?
a. b. c. d. e.
Mineral / Ore Fe2O3 / hematite CaCO3 / limestone PbS / gypsum BaSO4 / barite FeS2 / iron pyrite
ANS: C OBJ: Identify the mineral and ore that do not match. TOP: Occurrence of the Metals 7. Which of the following statements about natural sources of the metals is incorrect? a. Iron is usually found as an oxide. b. Metals are extracted from the compounds contained in ores in the earth's crust. c. Ores contain minerals mixed with relatively large amounts of gangue. d. Gold, platinum, and palladium are found as uncombined native ores. e. Metal ores can be classified by the cations with which the metal ions are combined. ANS: E OBJ: Identify the incorrect description of natural sources of metals. TOP: Occurrence of the Metals 8. Metals are seldom obtained from silicate minerals. Why? a. The amount of silicate minerals on earth is very small. b. Almost no desirable metals exist as silicate mineral ores. c. The extraction of metals from silicates is very difficult and costly. d. Those few metals that exist as silicate ores are more cheaply available as native ores. e. Extraction of metals from silicates produces environmentally dangerous wastes. ANS: C OBJ: Identify the reason metals are seldom obtained from silicates. TOP: Occurrence of the Metals 9. Which of the following is not one of the five possible steps of metallurgy? a. mining the ore b. pretreatment of the ore c. reduction of ore to free metal d. refining or purifying the metal e. disposal of metal after it has been used
Whitten 10e
Test Bank
860
ANS: E OBJ: Identify the process that is not part of metallurgy. TOP: Pretreatment of Ores 10. Mixing a metal with other substances to modify its properties is known as ____. a. refining b. alloying c. roasting d. smelting e. charging ANS: B OBJ: Identify the definition of alloy. TOP: Pretreatment of Ores 11. Which one of the following is a metallurgical pretreatment process? a. alloying b. distillation c. reduction d. flotation e. refining ANS: D OBJ: Identify a metallurgical pretreatment process. TOP: Pretreatment of Ores 12. Why is pretreatment of ore necessary in metallurgy? a. To separate the gangue from the ore. b. To concentrate the mineral in the ore. c. To convert the metal-containing compounds into more easily reduced forms. d. Both (a) and (b) are correct. e. Both (a), (b), and (c) are correct. ANS: E OBJ: Identify the reasons for ore pretreatment. TOP: Pretreatment of Ores 13. The cyclone separator is used in ____. a. a blast furnace b. roasting c. smelting d. electrolysis e. the pretreatment of ores ANS: E OBJ: Identify the use of a cyclone separator. TOP: Pretreatment of Ores 14. What two kinds of particles are separated in the flotation process? a. hydrophobic and hydrophilic b. ionic and covalent c. acidic and basic d. metallic and nonmetallic e. oxidized and reduced
Whitten 10e
Test Bank
861
ANS: A OBJ: Identify the two particle types separated by flotation. TOP: Pretreatment of Ores 15. Which one of the following is not converted to a metal oxide upon heating in air? a. ZnS b. Mg(OH)2 c. CaCO3 d. HgS e. NiS ANS: D OBJ: Identify the compound that does not make a metal oxide when burned. TOP: Pretreatment of Ores 16. What mass of CO2 would be produced by heating a 500.-kg sample of limestone that is 75.0% CaCO3? Assume complete reaction and no other source of carbon dioxide. a. 165 kg b. 220. kg c. 180. kg d. 225 kg e. 188 kg ANS: A OBJ: Calculate the mass of carbon dioxide produced from heat treatment of limestone sample of known composition. TOP: Pretreatment of Ores 17. What volume of CO2 at STP would be produced by heating a 100.-g sample of limestone that is 82.0% CaCO3? Assume complete reaction, and no other source of carbon dioxide. a. 0.183 L b. 18.4 L c. 26.7 L d. 22.4 L e. 12.3 L ANS: B OBJ: Calculate the volume of carbon dioxide produced from heat treatment of limestone sample of known composition. TOP: Pretreatment of Ores 18. What mass of MgO would be produced by heating a 150.-g sample that is 65.0% Mg(OH)2? Assume complete reaction and no other source of magnesium. a. 141 g b. 97.5 g c. 67.4 g d. 104 g e. 95.4 g ANS: C OBJ: Calculate the mass of metal oxide produced from heat treatment of a metal hydroxide of known composition. TOP: Pretreatment of Ores
Whitten 10e
Test Bank
862
19. A 210.g-sample of sphalerite is roasted and produces 128.0 g of ZnO. Assuming complete reaction and no other source of zinc, calculate the percentage of ZnS in the sphalerite. a. 72.9% b. 50.9% c. 61.0% d. 83.5% e. 49.0% ANS: A OBJ: Calculate the percent composition of an ore given the mass of the original sample and the mass of metal oxide produced from heat treatment. TOP: Pretreatment of Ores 20. Why is reduction necessary in metallurgy? a. It creates alloys with improved properties. b. It converts the free metal into anions. c. It concentrates the metal in the ore. d. Most metals exist naturally as cations in the oxidized state. e. Reduction separates the gangue from the ore. ANS: D OBJ: Identify the purpose of reduction in metallurgy. TOP: Reduction to the Free Metals 21. Which of the following metals can be obtained from its ores only by electrolysis of a molten salt? a. Zn b. Cr c. Cu d. Ag e. Ca ANS: E OBJ: Identify the metal obtainable only by electrolysis of its ores. TOP: Reduction to the Free Metals 22. Which of the following metals can be obtained from its ores without using electrolysis? a. K b. Fe c. Al d. Na e. Li ANS: B OBJ: Identify the metal that can be obtained from its ores without electrolysis. TOP: Reduction to the Free Metals 23. Which of the following species cannot function as a reducing agent in metallurgy? a. F2 b. H2 c. C d. CO e. Al
Whitten 10e
Test Bank
863
ANS: A OBJ: Identify the species that is not a reducing agent in metallurgy. TOP: Reduction to the Free Metals 24. Titanium metal is produced by converting the oxide (TiO2) to the halide salt (TiCl4) and then reducing the halide salt with an active metal TiCl4 + 2Mg
Ti + 2MgCl2
What other metal is produced using the same reduction process? a. U b. Al c. Na d. Fe e. Ca ANS: A OBJ: Identify the metal produced in a reductive process similar to titanium. TOP: Reduction to the Free Metals 25. What mass of Hg would be produced by heating a 120.g-sample of cinnabar that is 82.0% HgS? Assume complete reaction and no other source of mercury. a. 103 g b. 91.1 g c. 107 g d. 84.8 g e. 114 g ANS: D OBJ: Calculate the mass of mercury obtained from heat treatment of sample of known composition. TOP: Reduction to the Free Metals 26. What mass of Na would be produced by the electrolysis of 219 grams of molten NaCl? a. 142 g b. 71 g c. 9.5 g d. 86 g e. 338 g ANS: D OBJ: Calculate the mass of sodium produced from a known amount of molten NaCl. TOP: Reduction to the Free Metals 27. Which of the following statements about the refining of metals is true? a. Metals obtained from reduction are usually impure. b. Al, Au, Ag, and Cu are metals refined by electrolysis. c. Zone refining produces extremely pure metals. d. Some metals can be refined by distillation. e. All of these statements are true. ANS: E OBJ: Identify the incorrect description of metal refinement. TOP: Refining of Metals
Whitten 10e
Test Bank
864
28. Which of the following involves the use of an induction heater? a. Hall process b. blast furnace c. zone refining d. electrolysis e. reverberatory furnace ANS: C OBJ: Identify the process that uses an induction heater. TOP: Refining of Metals 29. Which of the following statements concerning zone refining is incorrect? a. Zone refining is used to produce extremely pure metals. b. The process consists of an induction heater, which surrounds an impure solid bar of metal, passing from one end of the bar to the other end. c. As the heater moves along the bar, it melts portions of the bar. d. As the heating element moves away, the melted portions of the bar recrystallize. e. The bar is purified because the impurities are burned out of the bar. ANS: E OBJ: Identify the incorrect description of zone refinement. TOP: Refining of Metals 30. What is a major natural source of magnesium? a. sea water b. native ore c. river water d. impurity in coal e. a by-product of purification of Cu ore ANS: A OBJ: identify a major natural source of magnesium. TOP: Magnesium 31. Which of the following is the reaction for the precipitation of Mg2+ ions from sea water? a. Mg2+(aq) + 2HCl(g) MgCl2(s) + 2H+(aq) b. Mg2+(aq) + Ca(OH)2(s) Mg(OH)2(s) + Ca2+(aq) c. Mg(s) + 2NaOH(aq) Mg(OH)2(s) + 2Na(s) d. Mg2+(aq) + O2(g) + H2(g) Mg(OH)2(s) e. Mg2+(aq) + H2S(g) MgS(s) + 2H+(aq) ANS: B OBJ: Identify the chemical reaction depicting the precipitation of magnesium ion from seawater. TOP: Magnesium 32. Sea water is 0.13% Mg by mass. What mass of sea water would be required to produce 50. g of Mg metal if the yield was 85%? a. 450 g b. 330 g c. 4.5 104 g d. 3.3 104 g e. 1.9 103 g
Whitten 10e
Test Bank
865
ANS: C OBJ: Calculate the mass of sea water required to produce a certain amount of magnesium given percent composition and percent yield. TOP: Magnesium 33. Which of the following statements about magnesium is false? a. Magnesium occurs widely in carbonate ores. b. Magnesium is a relatively inactive metal. c. Sea water is 0.13% magnesium by mass. d. Magnesium is used in lightweight structural alloys. e. Magnesium is produced through the electrolysis of molten MgCl2. ANS: B OBJ: Identify the incorrect fact about magnesium. TOP: Magnesium 34. The most commercially important nonferrous metal is ____. a. aluminum b. tin c. titanium d. gold e. copper ANS: A OBJ: Identify the most commercially important nonferrous metal. TOP: Aluminum 35. Four of the following statements are applicable to aluminum or to the metallurgy of aluminum. One is not. Which one? a. Aluminum is obtained from oxide ores. b. The amphoteric nature of aluminum hydroxide is the basis for an important step in the metallurgy of aluminum. c. Graphite anodes are used in the electrolytic cell in which aluminum is produced, and these anodes are gradually converted to oxides. d. Aluminum is widely used as a structural material because metallic aluminum is resistant to oxidation by air. e. Recycled aluminum accounts for more than half of the production of this metal. ANS: D OBJ: Identify the description that is not applicable to aluminum metallurgy. TOP: Aluminum 36. The Hall-Heroult process electrolyzes a molten mixture of Al2O3 and cryolite, Na3[AlF6], to reduce the aluminum cations to aluminum metal. Why is cryolite used in the mixture? a. It lowers the E0 for the reduction of the aluminum cations. b. It raises the E0 for the reduction of the aluminum cations. c. It increases the conductivity of the mixture. d. It lowers the melting point of the mixture, thereby lowering the cost of the energy needed to melt the mixture. e. It increases the yield by putting more aluminum in the mixture. ANS: D OBJ: Identify the purpose of cryolite in the Hall-Heroult process. TOP: Aluminum
Whitten 10e
Test Bank
866
37. A new economical process for the production of aluminum has been developed on a commercial scale. It uses up to 60% as much electrical energy as the Hall-Heroult process. What is the name of this new process? a. Reynolds process b. zone process c. Alcoa chlorine process d. basic oxygen process e. blast process ANS: C OBJ: Identify the aluminum production process that requires less electrical energy than the HallHeroult process. TOP: Aluminum 38. Which of the following pairs that refer to the metallurgy of iron / steel are incorrectly matched? a. pig iron / iron obtained from a blast furnace b. zinc / added to steel to make it stainless steel c. slag / calcium silicate by-product d. coke / form of carbon obtained from coal e. CO / reducing agent in the metallurgy of iron ANS: B OBJ: Identify the mismatched iron and steel metallurgy term and description. TOP: Iron 39. The iron obtained from the blast furnace contains carbon and is called ____. a. steel b. pig iron c. cast iron d. slag e. molten iron ANS: B OBJ: Identify the name of the iron obtained from a blast furnace. TOP: Iron 40. Four of the following statements are applicable to the metallurgy of iron. Which one is not? a. The ore is roasted to remove water, decompose carbonates, and oxidize sulfides. b. Large amounts of coke are used in producing iron. c. Carbon monoxide is the reducing agent. d. Limestone is added to form slag with silicate impurities in the ore. e. Mercury compounds are added to the blast furnace to form the very insoluble HgS (Ksp = 3 1053) to reduce pollution of the air by release of volatile sulfur-containing compounds. ANS: E OBJ: Identify the description not applicable to iron metallurgy. TOP: Iron 41. The calcium silicate formed in the blast furnace reduction of iron ore is called ____. a. charge b. gangue c. pig iron d. flux e. slag
Whitten 10e
Test Bank
867
ANS: E OBJ: Identify name of the calcium silicate formed in a blast furnace. TOP: Iron 42. The two most desirable iron ores are Fe2O3 and Fe3O4. Which contains the highest percentage of iron, and what is that percentage? a. Fe2O3; 69.9% b. Fe3O4; 72.4% c. Fe2O3; 35.0% d. Fe2O3; 40.0% e. Fe3O4; 77.7% ANS: B OBJ: Identify the ore with the highest percentage of iron and calculate the percent iron. TOP: Iron 43. What mass of Fe would be contained in a 80.0-g sample of hematite ore that is 76.0% Fe2O3? Assume no other form of Fe is present. a. 55.9 g b. 47.2 g c. 24.3 g d. 42.5 g e. 60.8 g ANS: D OBJ: Calculate the mass of iron in an ore of known composition. TOP: Iron 44. What mass of Fe would be contained in a 80.0-g sample of magnetite ore that is 76.0% Fe3O4? Assume no other form of Fe is present. a. 24.3 g b. 44.0 g c. 56.0 g d. 57.2 g e. 26.1 g ANS: B OBJ: Calculate the mass of iron in an ore of known composition. TOP: Iron 45. One of the following occurs as a native ore to a significant extent in a few locations on the earth's surface, but it is obtained commercially from low-grade ores. Which one? a. Hg b. Al c. Fe d. Cu e. Ba ANS: D OBJ: Identify the metal that occurs as native ores but is obtained commercially from low grade ores. TOP: Copper
Whitten 10e
Test Bank
868
46. Which of the following is not a copper containing mineral? a. chalcopyrite b. chalcocite c. limestone d. malachite e. azurite ANS: C OBJ: Identify the ore that does not contain copper. TOP: Copper 47. Which equation best represents the reaction that occurs during the roasting of chalcocite, which contains copper(I) sulfide? a. 2Cu SO + O 2Cu SO 2
3
2
2
b. 2CuS + 3O2 2CuO + 2SO2 c. Cu S + O 2Cu + SO2 2 2 d. Cu2S + O2 2CuO + S e. none of these
4
ANS: C DIF: Harder Question OBJ: Identify the chemical equation representing the burning of copper(I) sulfide. TOP: Copper 48. Four of the following statements are applicable to the metallurgy of copper. Which one is not applicable? a. Copper is obtained primarily from low-grade sulfide ores. b. Coke is used as a reducing agent in the production of copper. c. The two main classes of copper ores are sulfides and basic carbonates. d. Copper is refined electrolytically by dissolving large bars of impure copper and redepositing copper onto thin plates of very pure copper in a copper(II) sulfate/sulfuric acid bath. e. Metals that are less active than copper are obtained from the anode mud when copper is refined, and the value of these less active metals may be great enough to pay for the refining of copper. ANS: B OBJ: Identify the description unrelated to copper metallurgy. TOP: Copper 49. Which one of the following elements would not be found in the anode mud of an electrolytic cell used to refine copper? a. Au b. Ag c. Pt d. K e. Se ANS: D OBJ: Identify the element not found in the anode mud of a copper refinement cell. TOP: Copper
Whitten 10e
Test Bank
869
50. A sample of azurite is 70.0% Cu3(CO3)2(OH)2. Calculate the percent copper in the ore. a. 18.4% b. 27.6% c. 38.7% d. 55.3% e. 61.2% ANS: C OBJ: Calculate the percent copper in an ore given the percent azurite in the ore. TOP: Copper 51. What mass of Cu would be present in 45.0 g of pure malachite, CuCO3Cu(OH)2? a. 25.8 g b. 22.6 g c. 15.3 g d. 29.0 g e. 17.4 g ANS: A OBJ: Calculate the mass of copper in a sample of malachite. TOP: Copper 52. The only compound containing copper in an ore is chalcopyrite, CuFeS2. If a 120.g-sample of this ore contains 25.6 g of copper, what is the percentage of CuFeS2 in the sample? a. 73.9% b. 61.6% c. 50.8% d. 42.8% e. 21.3% ANS: B OBJ: Calculate the percent of a copper containing compound in an ore sample given the mass of copper. TOP: Copper 53. Which of the following statements about the metallurgy of gold is incorrect? a. Gold can be recovered by reacting it with NaCN. b. Gold can be found in its native state. c. Gold can be recovered from anode sludge from the electrolytic purification of copper. d. The low density of gold allows it to be recovered by panning. e. Gold can be recovered by alloying it with mercury. ANS: D OBJ: Identify the incorrect description of gold metallurgy. TOP: Gold 54. Which property of gold allows for it to be recovered by panning? a. Gold is an inactive metal. b. Gold is very rare. c. Gold has high density. d. Gold has a high melting point. e. Gold is a soft metal.
Whitten 10e
Test Bank
870
ANS: C OBJ: Identify the property of gold that allows for its isolation by panning. TOP: Gold 55. Gold is often recovered by alloying it with mercury. How is the gold and mercury then separated? a. The mercury is oxidized and dissolved in water. b. The gold is reduced to the free metal which sinks to the bottom of the mercury and the liquid mercury is poured off. c. The gold is reacted with NaCN to form a complex ion that is soluble in water. d. The mercury is distilled away. e. Electrolytic reduction is used to separate the gold and mercury. ANS: D OBJ: Identify how a gold is separated from it mercury alloy. TOP: Gold 56. Sodium cyanide is an important reagent in the metallurgy of ____. a. Mg b. Fe c. Cu d. Au e. K ANS: D OBJ: Identify the metal that is isolated from its ores using cyanide ion. TOP: Gold 57. Why is the cyanide process for gold purification preferred over the use of mercury? a. Mercury is much, much more poisonous than cyanide. b. Costly electrolysis is required to separate the gold from mercury. c. Mercury persists in the environment for a long time, and its poisoning is cumulative. d. Gold is too reactive a metal and may react dangerously with mercury. e. Mercury is a liquid and is much more difficult to handle safely compared to cyanide. ANS: C OBJ: Identify the preference for cyanide purification of gold relative to mercury. TOP: Gold 58. Much gold is found as the native ore, but some is also found as: a. gold oxide b. gold sulfide c. gold carbonate d. gold silicate e. gold telluride ANS: E OBJ: Identify a natural source of gold other than the native ore. TOP: Gold 59. Which element is found in the ore chalcopyrite? a. Cu b. Ti c. Zn d. Hg e. Fe Whitten 10e
Test Bank
871
ANS: A OBJ: Identify the metal extracted from a given ore. TOP: Ores 60. Which element may occur in native ores? a. Ag b. Mg c. Fe d. Zn e. Al ANS: A OBJ: Identify the metal that occurs as a native ore. TOP: Occurrence of the Metals 61. Which of the following is not a metallurgical pretreatment process? a. pulverization b. flotation c. sifting d. chemical modification e. smelting ANS: E OBJ: Identify the process that is not a pretreatment process in metallurgy. TOP: Pretreatment of Ores 62. Major natural sources of Ni, Cu, and Hg occur as a. carbonates. b. halide salts. c. sulfides. d. oxides. e. phosphates. ANS: C OBJ: Identify the major natural source of an element. TOP: Occurrence of the Metals 63. What mass of CO2 would be produced by heating a 300.-kg sample of limestone that is 52.0% CaCO3? Assume complete reaction and no other source of carbon dioxide. a. 68.6 kg b. 355 kg c. 1.56 kg d. 132 kg e. 682 kg ANS: A OBJ: Calculate the mass of carbon dioxide produced from heat treatment of a limestone sample of known composition. TOP: Pretreatment of Ores
Whitten 10e
Test Bank
872
64. What mass of CaO would be produced by heating a 200.-kg sample that is 68.0% Ca(OH)2? Assume complete reaction and no other source of calcium. a. 103 kg b. 184 kg c. 1.84 kg d. 264 kg e. 151 kg ANS: A OBJ: Calculate the mass of metal oxide produced from heat treatment of a metal hydroxide sample of known composition. TOP: Pretreatment of Ores 65. What mass of Cu(OH)2 would produce 550. kg CuO after roasting? Assume complete reaction. a. 675 kg b. 448 kg c. 564 kg d. 550. kg e. 1230 kg ANS: A OBJ: Calculate the mass of metal hydroxide required to produce a given amount of metal oxide after roasting. TOP: Pretreatment of Ores 66. What mass of Cu would be present in 42.0 g of pure malachite, CuCO3Cu(OH)2? a. 36.5 g b. 24.1 g c. 12.1 g d. 14.6 g e. 0.661 g ANS: B OBJ: Calculate the mass of copper in a sample of malachite.
TOP: Copper
67. The only compound containing copper in an ore is chalcopyrite, CuFeS2. If a 90.0 g-sample of this ore contains 22.0 % of copper, what is the percentage of CuFeS2 in the sample? a. 24.4% b. 6.86% c. 0.635% d. 57.2% e. 42.8% ANS: D OBJ: Calculate the percent of a copper containing compound in an ore sample given the percent copper. TOP: Copper 68. A sample of azurite is 73.0% Cu3(CO3)2(OH)2. Calculate the percent copper in the ore. a. 46.4% b. 86.5% c. 13.5% d. 53.6% e. 27.0%
Whitten 10e
Test Bank
873
ANS: C OBJ: Calculate the percent copper in an ore given the percent azurite in the ore. TOP: Copper CONCEPTUAL 69. Suppose you discovered a new ore. Describe the procedures you would try, in the order you would try them, to obtain the free metal. Would you start with electrolysis first or last? Explain. OBJ: Describe the process you would follow to isolate the free metal from a newly discovered ore. TOP: Pretreatment of Ores | Reduction to the Free Metals | Refining of Metals 70. Consider the valuable metals gold, silver, platinum and copper. How is their use in jewelry and coins related to their chemical properties? OBJ: Relate the usage of gold, silver, platinum, and copper in jewelry to their chemical properties. TOP: Activity Series | Reduction Potentials |Occurrence of the Metals 71. Relate the history of man's ability to obtain different free metals to the history of engineering and technology. OBJ: Correlate metal refinement through time with the history of engineering and technology. TOP: Occurrence of the Metals | Reduction to the Free Metals 72. Discuss the negative effects of metallurgical processes on the environment, including acid rain, strip mining, and others. What steps have been taken to reduce these effects? OBJ: Describe the environmental effects of metallurgical processes and the steps taken to reduce these effects. TOP: Pretreatment of Ores | Reduction to the Free Metals | Refining of Metals 73. Discuss zone refining. Why is it so expensive? Name three or four uses for metals where extremely high purity is necessary and could therefore benefit from zone refining. OBJ: Explain the process of zone refinement, its economic impact, and list some metals where extremely high purity is required. TOP: Refining of Metals
Chapter 27—Metals II: Properties and Reactions MULTIPLE CHOICE 1. The alkali metals are examples of ____ metals. a. transition b. post-transition c. alkaline earth d. representative e. native ANS: D OBJ: Classify the alkali metals. TOP: Group 1A Metals: Properties and Occurrence Whitten 10e
Test Bank
874
2. Which one of the following properties of the alkali metals does not increase as the group is descended? a. density b. atomic radius c. first ionization energy d. ionic radius e. all of these increase ANS: C OBJ: Identify the property that does not increase down a group. TOP: Group 1A Metals: Properties and Occurrence 3. All the isotopes of ____ are radioactive. a. Li b. K c. Rb d. Cs e. Fr ANS: E OBJ: Identify the element whose isotopes are all radioactive. TOP: Group 1A Metals: Properties and Occurrence 4. Which one of the following cations has the greatest ability to polarize anions? a. Li+ b. Na+ c. K+ d. Rb+ e. Cs+ ANS: A OBJ: Identify the cation with the greatest ability to polarize anions. TOP: Group 1A Metals: Properties and Occurrence
Whitten 10e
Test Bank
875
5. Which statement concerning alkali metals is incorrect? a. Alkali metals are not found free in nature because they are so easily oxidized. b. The free metals, except lithium, are soft, silvery metals that can be cut with a knife. c. The free metals are very corrosive. d. All of the free metals have melting points above 100C. e. These metals are excellent electrical and thermal conductors. ANS: D OBJ: Identify the incorrect description of alkali metals. TOP: Group 1A Metals: Properties and Occurrence 6. The electronegativities of the IA metal ions follow which trend below? a. Little variance in electronegativity, with all having a low value. b. Decreasing greatly in value from top to bottom. c. Increasing greatly in value from top to bottom. d. Low at the top, high in the middle, low at the bottom. e. Little variance in electronegativity, with all having a high value. ANS: A OBJ: Identify the electronegativity trend of the Group IA metal ions. TOP: Group 1A Metals: Properties and Occurrence 7. Which statement concerning Li+ ions is incorrect? a. Li+ ions have a higher charge density than other IA ions. b. Li+ ions can polarize large anions. c. Li+ ions exert a stronger attraction for H2O molecules than do other IA cations. d. The magnitude of the standard reduction potential of Li is unexpectedly large. e. Li compounds have more ionic character than other corresponding IA metal compounds. ANS: E OBJ: Identify the incorrect description of the lithium ion. TOP: Group 1A Metals: Properties and Occurrence 8. What is not a contributing factor to the fact that the magnitude of the standard reduction potential of Li is unexpectedly large compared to other IA metals? a. The Li+ ion is very small. b. The charge density (ratio of charge to size) is very high for Li+ ions. c. The Li+ ions exert a stronger attraction for H2O molecules than do other IA ions. d. During reduction the H2O molecules must be stripped off the Li+ ion, which is a very endothermic process. e. Lithium has the smallest atomic weight of the IA metals. ANS: E DIF: Harder Question OBJ: Identify the property that does not contribute to the large magnitude of the reduction potential of lithium. TOP: Group 1A Metals: Properties and Occurrence 9. Which of the following compounds is a peroxide? a. Li2O b. Na2O2 c. KO2 d. MnO2 e. TiO2
Whitten 10e
Test Bank
876
ANS: B OBJ: Identify the formula of a peroxide. TOP: Reactions of the Group 1A Metals 10. Li, as is often true for elements of the second period, differs in many ways from the other members of its family. Li compounds often resemble the compounds of what element? a. Be b. Mg c. Al d. Na e. B ANS: B OBJ: Identify the element that whose compounds resemble lithium compounds. TOP: Reactions of the Group 1A Metals 11. What is the product of the reaction of potassium with elemental phosphorus, P4? a. KP b. K2P c. KP2 d. K3P e. KP3 ANS: D OBJ: Identify the product given the reactants. TOP: Reactions of the Group 1A Metals 12. Which of the following statements about the Group I metals is false? a. They will react vigorously with water. b. They must be stored under anhydrous nonpolar liquids. c. The IA metal halides react vigorously with water. d. They can react with water vapor in the air. e. The IA metal oxides are basic. ANS: C OBJ: Identify the incorrect description of the Group I metals. TOP: Reactions of the Group 1A Metals 13. Which of the following is not an example of the diagonal similarities of Li and Mg compounds? a. Li, unlike other IA metals, combines with N2 to form a nitride as does Mg. b. Both Li and Mg readily combine with carbon to form carbides; other IA metals do not. c. Both metals exhibit the +1 oxidation state in most of their compounds. d. The solubilities of Li compounds are closer to the corresponding Mg compounds than those of other IA metal compounds. e. Li and Mg form normal oxides when burned in air; other alkali metals form peroxides and superoxides. ANS: C OBJ: Identify the description that is not consistent with the similarities of Mg and Li compounds. TOP: Reactions of the Group 1A Metals
Whitten 10e
Test Bank
877
14. Which one of the following compounds or elements is not correctly matched with a use?
a. b. c. d. e.
Substance / Use KNO3 / fertilizer NaOH / production of paper Cs / photoelectric cells Rb2SO4 / textiles Li / treatment of manic depression
ANS: D OBJ: Identify the compound not correctly matched with its use. TOP: Uses of Group 1A Metals and Their Compounds 15. Which one of the following compounds is not correctly matched with its common name?
a. b. c. d. e.
Compound / Common Name NaOH / caustic soda Na2CO310H2O / washing soda Na2SO4 / Chile saltpeter NaHCO3 / baking soda Na2CO3 / soda or soda ash
ANS: C OBJ: Identify the compound not correctly matched with its common name. TOP: Uses of Group 1A Metals and Their Compounds 16. What property of metallic lithium makes it a good choice as a heat transfer medium in experimental nuclear reactors? a. high heat capacity b. low density c. not corrosive d. high melting point e. small atomic size for a IA metal ANS: A OBJ: Identify the property of metallic lithium that makes it useful in nuclear reactors. TOP: Uses of Group 1A Metals and Their Compounds 17. Which of the following was the first trace element shown to be essential to human nutrition? a. Al b. Fe c. Zn d. Co e. Ni ANS: B OBJ: Identify the first trace element shown to be essential to human nutrition. TOP: Trace Elements and Life
Whitten 10e
Test Bank
878
18. Which one of the following has not been demonstrated to be essential to either human or animal nutrition? a. Cr b. W c. Mo d. Se e. As ANS: B OBJ: Identify the element that has not been demonstrated to be important in human or animal nutrition. TOP: Trace Elements and Life 19. Which one of the following has been shown to be present in at least 200 enzymes? a. Al b. Cu c. Zn d. Co e. Mo ANS: C OBJ: Identify the element found in a minimum of 200 enzymes. TOP: Trace Elements and Life 20. Which trace element is deficient in up to 60% of the women and children in some countries? a. Zn b. Co c. Mn d. F e. Fe ANS: E OBJ: Identify the element that is deficient in up to 60% of women and children in some countries. TOP: Trace Elements and Life 21. Which metal is present in vitamin B12? a. nickel b. iron c. zinc d. cobalt e. chromium ANS: D OBJ: Identify the metal element present in vitamin B. TOP: Trace Elements and Life 22. Which statement concerning essentiality of trace elements is false? a. Some elements are toxic, and it is difficult to convince health specialists that a toxic element could be a dietary essential at low levels. b. Activation analysis and electrothermal atomic absorption spectroscopy allow detection of trace elements in concentrations of a few parts per billion. c. Chromium is one trace element that can be easily measured in most laboratories. d. New laboratories are equipped to measure these elements with the necessary precision. e. Contamination is a serious problem both in analytical laboratories and for controlling conditions for animal studies. Whitten 10e
Test Bank
879
ANS: C OBJ: Identify the incorrect description of trace elements. TOP: Trace Elements and Life 23. Few laboratories in the world can accurately measure Cr in food and body tissue. Why? a. The samples containing Cr decompose before measurements can be made. b. The Cr reacts with air too quickly to allow accurate measurement. c. Neither activation analysis nor electrothermal atomic absorption spectroscopy can detect Cr. d. The sample cannot be prepared for analysis without destroying some of the Cr. e. The stainless steel commonly present in analytical laboratories contains Cr which easily contaminates samples. ANS: E OBJ: Identify why trace chromium is difficult to measure. TOP: Trace Elements and Life 24. The properties of beryllium compounds are likely to resemble those of ____ compounds. a. Al b. B c. Li d. Sc e. Na ANS: A OBJ: Identify the element with properties similar to Be. TOP: Group 2A Metals: Properties and Occurrence 25. Which one of the following metals has the greatest tendency to form covalent compounds? a. Ca b. Be c. Sr d. Ba e. Rb ANS: B OBJ: Identify the metal with the greatest tendency to form covalent compounds. TOP: Group 2A Metals: Properties and Occurrence 26. Which statement concerning alkaline earth (IIA) metals is incorrect? a. The IIA metals are too reactive to occur free in nature. b. The IIA metals are obtained by electrolysis of their molten chlorides. c. Most oxides of IIA metals are amphoteric. d. All known isotopes of radium are radioactive. e. The IIA metals have a wider range of chemical properties than the IA metals. ANS: C OBJ: Identify the incorrect description of the alkaline earth metals. TOP: Group 2A Metals: Properties and Occurrence
Whitten 10e
Test Bank
880
27. Which one of the following metals reacts least vigorously with water? a. K b. Na c. Sr d. Ca e. Mg ANS: E OBJ: Identify the metal that reacts least vigorously with water. TOP: Reactions of the Group 2A Metals 28. Which of the Group IIA elements is least metallic? a. Be b. Mg c. Ca d. Sr e. Ba ANS: A OBJ: Identify the least metallic alkaline earth metal. TOP: Reactions of the Group 2A Metals 29. Which one of the following oxides has the most basic character? a. Al2O3 b. B2O3 c. BeO d. MgO e. CaO ANS: E OBJ: Identify the most basic oxide. TOP: Reactions of the Group 2A Metals 30. Which of the following is not oxidized in the presence of air? a. Be b. Mg c. Ca d. Sr e. Ba ANS: A OBJ: Identify the element not oxidized in air. TOP: Reactions of the Group 2A Metals 31. Which one of the following is most likely to substitute for Ca2+ in compounds in animal (including human) bodies? a. Ba2+ b. Sr2+ c. K+ d. Na+ e. Be2+ ANS: B OBJ: Identify the ion with chemistry similar to calcium ion. TOP: Reactions of the Group 2A Metals Whitten 10e
Test Bank
881
32. Which Group IIA metal forms an impervious coating of oxide that protects it from further oxidation? a. Mg b. Ca c. Sr d. Ba e. Ra ANS: A OBJ: Identify the alkaline earth that forms an impervious oxide coating. TOP: Uses of Group 2A Metals and Their Compounds 33. Which one of the following compounds or elements and its uses do not match?
a. b. c. d. e.
Substance / Use CaSO42H2O / plaster of Paris SrCl2 / toothpaste SrSO4 / absorbs x-rays Be / windows for x-ray tubes Mg / alloys for building materials
ANS: C OBJ: Identify the compound not correctly matched with its use. TOP: Uses of Group 2A Metals and Their Compounds 34. Which one of the Group IIA elements is used as a reducing agent in the metallurgy of uranium, thorium and other metals? a. Be b. Mg c. Ca d. Sr e. Ba ANS: C OBJ: Identify the alkaline earth that is used as a reducing agent in certain metallurgical processes. TOP: Uses of Group 2A Metals and Their Compounds 35. Which one of the following is a post-transition metal? a. strontium b. cesium c. chromium d. lead e. mercury ANS: D OBJ: Identify the post transitional metal. TOP: The Post-Transition Metals 36. The most abundant metal in the earth's crust is ____. a. sodium b. calcium c. potassium d. aluminum e. iron
Whitten 10e
Test Bank
882
ANS: D OBJ: Identify the most abundant metal in the earths crust. TOP: The Post-Transition Metals 37. Which of the following statements about aluminum is false? a. Aluminum is used as a lightweight structural metal. b. Aluminum is a weak reducing agent used in metallurgy. c. Aluminum is used in electrical transmission lines. d. Aluminum is used in the thermite reaction to produce molten iron for welding steel. e. Aluminum occurs naturally in sapphires and rubies. ANS: B OBJ: Identify the incorrect description of aluminum. TOP: The Post-Transition Metals 38. Which one of the following metals exhibits the inert s-pair effect? a. Na b. K c. Mg d. Al e. Sn ANS: E OBJ: Identify the element that exhibits the inert s-pair effect. TOP: The Post-Transition Metals 39. Which metal melts if held in the hand and has the largest liquid state temperature range of any element (29.8C and 2403C)? a. B b. Al c. Ga d. In e. Tl ANS: C OBJ: Identify the element with the stated physical properties. TOP: The Post-Transition Metals 40. Aluminum does not dissolve to a significant extent in concentrated HNO3 because ____. a. It is an inactive metal. b. Its E0 value for reduction of its cation is too negative. c. It forms a protective oxide coating that is resistant to further attack by HNO3. d. Its E0 value for reduction of its cation is too positive. e. Aluminum nitrate is insoluble in water. ANS: C OBJ: Identify the reason for the minimal dissolution of Al in nitric acid. TOP: The Post-Transition Metals 41. Which of the following statements is incorrect? a. Thallium is very toxic and has no important uses as a free metal. b. The greatest use for indium is in electronics. c. Gallium-67 was one of the first artificially produced isotopes used in medicine. d. Aluminum is the most reactive of the post-transition metals. e. Boron is a post-transition metal that crystallizes as a covalent solid. Whitten 10e
Test Bank
883
ANS: E OBJ: Identify the incorrect description of post-transition metals. TOP: The Post-Transition Metals 42. What is the name of the reaction that generates enough heat to produce molten iron for welding? a. Friedel-Crafts reaction b. thermite reaction c. Haber process d. Hofmann elimination e. Michael reaction ANS: B OBJ: Identify the reaction name given the products. TOP: The Post-Transition Metals 43. Which one of the following statements about gallium (Ga) is incorrect? a. Ga will melt if held in the hand. b. Ga has the largest liquid state temperature range of any element (29.8 2403C). c. Ga is used in transistors and high-temperature thermometers. d. Ga-67 was the first naturally occurring isotope to be used in medicine. e. The atomic radius of Ga is less than that of Al which is the Group IIIA element just above it in the periodic table. ANS: D OBJ: Identify the incorrect description of gallium. TOP: The Post-Transition Metals 44. The radii of Ga, In and Tl are smaller than would be predicted from the radii of the preceding Group IIIA elements, B and Al, with the radius of Ga being even smaller than the radius of Al. What is the explanation for this? a. Ga, In and Tl have an ns2np1 outer electron configuration. b. Ga, In and Tl have no partially filled shells. c. Ga, In and Tl have filled ns subshells. d. Ga, In and Tl can experience the inert s-pair effect. e. The increase in nuclear charge that accompanies the filling of the (n 1)d subshell causes a contraction in the size of the atoms of Ga, In and Tl. ANS: E OBJ: Identify the explanation for the variation of size of the Group IIIA elements. TOP: The Post-Transition Metals 45. Which of the following is a d-transition metal? a. K b. Sr c. Tc d. Pb e. Ga ANS: C OBJ: Identify the d-transition metal. TOP: General Properties – The d-Transition Metals
Whitten 10e
Test Bank
884
46. Which one of the following is not a general property of transition elements? a. All are metals. b. Most of them exhibit multiple oxidation states. c. Most are softer than nontransition metals. d. Many of these metals and their compounds are effective as catalysts. e. Many of their compounds are paramagnetic. ANS: C OBJ: Identify the incorrect property of the transition elements. TOP: General Properties – The d-Transition Metals 47. Which one of the following statements about the general properties of most d-transition metals is false? a. They have higher melting points than most nontransition metals. b. Compounds that contain their ions are often colored. c. They form complex ions. d. They each exhibit a single oxidation state. e. Most are paramagnetic. ANS: D OBJ: Identify the incorrect property of most d-transition elements. TOP: General Properties – The d-Transition Metals 48. Which of the following has more than one nonzero oxidation number? a. Zn b. Sc c. V d. Ag e. Ni ANS: C OBJ: Identify the element with more than one non-zero oxidation state. TOP: General Properties – The d-Transition Metals 49. The nitrate of which one of the following cations would be expected to be colorless in aqueous solution? a. Cr3+ b. Co2+ c. Ni2+ d. Cu2+ e. Ca2+ ANS: E OBJ: Identify the colorless ion. TOP: General Properties – The d-Transition Metals 50. Substances that contain unpaired electrons are attracted weakly into magnetic fields and are said to be ____. a. diamagnetic b. ferromagnetic c. degenerate d. ferrimagnetic e. paramagnetic
Whitten 10e
Test Bank
885
ANS: E DIF: Harder Question OBJ: Recognize the definition of paramagnetic. TOP: General Properties – The d-Transition Metals 51. Which of the following is the electron configuration of Co3+? a. [Ar]3d5 b. [Ar]3d74s2 c. [Ar]3d44s2 d. [Ar]3d6 e. [Ar]3d84s1 ANS: D OBJ: Identify the electron configuration of a metal ion. TOP: General Properties – The d-Transition Metals 52. Given below are the electron configurations for several neutral atoms or ions. Which represent species that would not be paramagnetic? I. [Ar]3d64s2 II. [Ar]3d104s2 III. [Ar]3d64s0 IV. [Ar]3d74s2 V. [Ar]3d104s0 VI. [Ar]3d54s1 a. b. c. d. e.
II and VI II and V I, II, III and V III and V I, II and VI
ANS: B OBJ: Identify the electron configurations consistent with a diamagnetic species. TOP: General Properties – The d-Transition Metals 53. Which one of the following species must be paramagnetic? a. Zn b. Zn2+ c. Sc3+ d. Mn e. Cu+ ANS: D DIF: Harder Question OBJ: Identify the paramagnetic species.
TOP: General Properties – The d-Transition Metals
54. Which one of the following statements is false? a. The maximum oxidation state of the Group IVB elements is +4. b. The most common oxidation states of the 3d-transition elements are +3 and +5. c. The elements in the middle of each d-transition series exhibit more oxidation states than those elements at either end. d. The maximum oxidation state of Group VIIB elements is +7. e. Elements of Group VB can exhibit the +3 oxidation state.
Whitten 10e
Test Bank
886
ANS: B OBJ: Identify the incorrect description of d-transition metals. TOP: Oxidation States – d-Transition Metals 55. Which one of the following d-transition metals would be expected to exhibit the largest number of oxidation states in its compounds? a. Sc b. Zn c. Mn d. Ni e. Ti ANS: C OBJ: Identify the element that exhibits the largest number of oxidation states. TOP: Oxidation States – d-Transition Metals 56. Which one of the following would be expected to be the most basic? a. Mn(OH)2 b. Mn(OH)3 c. H2MnO3 d. H2MnO4 e. HMnO4 ANS: A OBJ: Identify the most basic compound. TOP: Oxidation States – d-Transition Metals 57. Consider transition metals losing electrons and becoming ionized. The outer s electrons lie outside the d electrons and are ____ lost during this process. a. never b. always the last electrons c. rarely d. always the first electrons e. sometimes ANS: D OBJ: Identify the fate of s electrons when transition metals are ionized. TOP: Oxidation States – d-Transition Metals 58. What is the electron configuration for Co2+? a. [Ar]3d54s2 b. [Ar]3d74s0 c. [Ar]3d64s0 d. [Ar]3d44s2 e. [Ar]3d64s1 ANS: B DIF: Harder Question OBJ: Identify the electron configuration of a metal ion. TOP: Oxidation States – d-Transition Metals
Whitten 10e
Test Bank
887
59. Which one of the following is most acidic? a. Cr(OH)2 b. Cr(OH)3 c. CrO d. Cr2O3 e. CrO3 ANS: E OBJ: Identify the most acidic compound. TOP: Chromium Oxides, Oxyanions, and Hydroxides 60. Which one of the following is most basic? a. Cr(OH)2 b. Cr(OH)3 c. CrO3 d. Cr2O3 e. H2Cr2O7 ANS: A OBJ: Identify the most basic compound. TOP: Chromium Oxides, Oxyanions, and Hydroxides 61. Consider a solution in which the chromate-dichromate equilibrium has been established. If the solution has a pH of 12, the ____ ion predominates and the solution is ____. 2CrO42 + 2H+ Cr2O72 + H2O Kc = 4.2 1014 a. b. c. d. e.
chromate; yellow dichromate; yellow chromate; orange dichromate; orange chromite; blue
ANS: A OBJ: Know the colors of the chromate and dichromate ions. | Apply LeChatelier's principle to determine the solution color and predominant ion the given pH and the equilibrium. TOP: Chromium Oxides, Oxyanions, and Hydroxides 62. Consider a solution in which the chromate-dichromate equilibrium has been established. If the solution has a pH of 2, the ____ ion predominates and the solution is ____. 2CrO42 + 2H+ Cr2O72 + H2O Kc = 4.2 1014 a. b. c. d. e.
chromate; yellow dichromate; yellow chromate; orange dichromate; orange chromite; blue
ANS: D OBJ: Know the colors of the chromate and dichromate ions. | Apply LeChatelier's principle to determine the solution color and predominant ion the given pH and the equilibrium. TOP: Chromium Oxides, Oxyanions, and Hydroxides
Whitten 10e
Test Bank
888
63. For the reversible reaction below, Kc = 4.2 1014 2CrO42 + 2H+ Cr2O72 + H2O What is the concentration of CrO42 ions in a solution of pH = 3.00, which is also 0.010 M in Cr2O72 ions? a. 6.6 1010 M b. 4.2 1011 M c. 4.9 106 M d. 2.4 1011 M e. 2.4 109 M ANS: C OBJ: Solve the equilibrium to determine an ion concentration. TOP: Chromium Oxides, Oxyanions, and Hydroxides 64. A sample of chromite ore is 28.0% FeCr2O4. What mass of sodium chromate can be obtained by heating 1.00 kg of the ore in air with excess sodium carbonate? 4FeCr2O4 + 8Na2CO3 + 7O2 2Fe2O3 + 8Na2CrO4 + 8CO2 a. b. c. d. e.
405 g 167 g 248 g 386 g 448 g
ANS: A OBJ: Calculate the mass of product generated from the heat treatment of an ore of known composition. TOP: Chromium Oxides, Oxyanions, and Hydroxides 65. What volume of 0.100 M potassium dichromate solution is necessary to oxidize 1.00 g of FeSO4 to Fe2(SO4)3, in the presence of excess H2SO4? The dichromate ion is reduced to Cr2(SO4)3. a. 22.0 mL b. 14.4 mL c. 18.7 mL d. 11.0 mL e. 43.8 mL ANS: D OBJ: Write a balanced redox reaction given the reactants and products and calculate the volume of oxidant required given the mass of the other reactant. TOP: Chromium Oxides, Oxyanions, and Hydroxides 66. What is the general formula for an alkali metal hydride? (M = metal) a. MH b. M(OH)2 c. MH2 d. MH3 e. MOH ANS: A DIF: easy OBJ: Identify the formula of a class of metal hydrides. TOP: Group 1A Metals: Properties and Occurrence Whitten 10e
Test Bank
889
67. Which of the following is not a d-transition metal? a. scandium b. rhodium c. rhenium d. ruthenium e. aluminum ANS: E DIF: easy OBJ: Identify the element that is not a d-transition element. TOP: General Properties – The d-Transition Metals 68. What is the maximum oxidation state expected for titanium? a. +4 b. +6 c. +2 d. +5 e. +3 ANS: A DIF: easy OBJ: Identify the highest oxidation state possible for the given early transition metal. TOP: Oxidation States – d-Transition Metals 69. Which of the following salts would not be expected to have unpaired d-electrons? a. NiCl2 b. CoCl2 c. MnCl2 d. TiCl3 e. ZnCl2 ANS: E DIF: easy OBJ: Determine the d-transition metal with no unpaired d-electrons. TOP: Oxidation States – d-Transition Metals 70. Which of the following oxides is amphoteric? a. CaO b. In2O3 c. Na2O d. MgO e. BeO ANS: E DIF: easy OBJ: Identify the amphoteric oxide. TOP: Basic and Amphoteric Oxides 71. Which of the following does not form a nitride? a. Sr b. Li c. Mg d. Cs e. Ca Whitten 10e
Test Bank
890
ANS: D DIF: easy OBJ: Identify the element that does not form a nitride. TOP: Reactions with Nitrogen 72. Which of the following electron configurations corresponds to the ground state of an atom of a dtransition element? a. 1s22s22p1 b. 1s22s22p63s23p63d104s24p2 c. 1s22s22p63s23p63d64s2 d. 1s22s22p63s23p64s2 e. 1s22s22p63s23p4 ANS: C DIF: easy OBJ: Identify the configuration consistent with a d-transition metal. TOP: General Properties – The d-Transition Metals 73. What is the total number of electrons in p orbitals in a ground-state chromium atom? a. 6 b. 18 c. 12 d. 24 e. 30 ANS: C DIF: moderate OBJ: Identify the number of p electrons in a d-transition metal. TOP: General Properties – The d-Transition Metals 74. The ground-state electron configuration of a a. paramagnetic with four unpaired electrons. b. diamagnetic. c. paramagnetic with one unpaired electron. d. paramagnetic with five unpaired electrons. e. paramagnetic with three unpaired electrons.
. Therefore,
is
ANS: A DIF: easy OBJ: Identify the number of unpaired electrons given the electron configuration. TOP: General Properties – The d-Transition Metals 75. The change in energy for which of the following processes corresponds to the second ionization energy of magnesium? a. b. c. d. e.
Whitten 10e
Test Bank
891
ANS: C DIF: moderate OBJ: Identify the representation of the second ionization energy. TOP: Ionization energy 76. Which of the following orbital notations shows the ground state electron configuration for
nickel? a.
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
b. c.
1s 2s
2p
3s
3p
4s
3d
d.
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
e.
ANS: B OBJ: Determine the electron configuration of the transition metal. TOP: General Properties – The d-Transition Metals 77. Which of the following orbital notations shows the complete electron configuration for the
iron(II) ion? a.
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
b. c. d. e.
ANS: A OBJ: Determine the electron configuration of the transition metal ion. TOP: General Properties – The d-Transition Metals 78. Which of the following orbital notations shows the complete electron configuration for the
chromium(III) ion? a.
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
b. c.
Whitten 10e
Test Bank
892
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
1s
2s
2p
3s
3p
4s
3d
d. e.
ANS: D OBJ: Determine the electron configuration of the transition metal ion. TOP: General Properties – The d-Transition Metals 79. Use the periodic trends to rank the size transition metals gold, mercury, iridium, and platinum
from smallest to largest: a. Hg < Au < Pt < Ir b. Ir < Pt < Au < Hg c. Au < Pt < Ir < Hg d. Pt < Ir < Hg < Au e. Hg < Ir < Au < Pt ANS: B OBJ: Rank the atomic radii of transition metals. TOP: General Properties – The d-Transition Metals 80. Which of the following are characteristics of main-group metals? a. Have high first ionization energies b. Are located along the diagonal line from B to Te c. Have low first ionization energies d. Have high effective nuclear charge e. Two of the above ANS: C OBJ: Identify a general characteristic of a main group metal. TOP: General Properties – The Main Group Metals 81. Which of the following equations shows the correct reaction between barium oxide and
water? a. BaO(s) + H2O(l) HBaO(aq) + OH-(aq) b. BaO(s) + H2O(l) H2BaO2(aq) c. BaO(s) + H2O(l) Ba(OH)2(aq) d. BaO(s) + 2H2O(l) BaH2(aq) + 2OH-(aq) e. none of the above ANS: C OBJ: Identify the reaction of a basic oxide with water. TOP: Basic and Amphoteric Oxides
Whitten 10e
Test Bank
893
CONCEPTUAL 1. Sapphires and rubies are valuable gemstones that get their coloring from impurities in aluminum oxide. They are extremely hard compared to most metal oxides. Discuss and compare the metallic character of this oxide based on location in the periodic table and the type of bonding involved (ionic or covalent?) of the aluminum. OBJ: Discuss the bonding in aluminum oxide relative to other metal oxides. TOP: The Post-Transition Metals 2. Galvanized metal is covered with a thin coating of zinc, which oxidizes to zinc oxide. Consider the number of oxidation states available to zinc, and propose a reason that galvanization protects the metal beneath it. OBJ: Explain the role of zinc in the protection of other metals. TOP: Corrosion Protection | Reduction Potentials 3. Compare the first ionization energies of cesium and sodium. Why is it easier to ionize cesium than sodium? OBJ: Explain why it is easier to ionize cesium than sodium. TOP: Ionization energy | Effective Nuclear Charge 4. Two commonly used qualitative tests for the presence of an alcohol group on an organic molecule are the Baeyer test and the dichromate test. In the Baeyer test, purple KMnO4 solution is added to a small amount of alcohol, whereas in the dichromate test, orange K2Cr2O7 is added to the alcohol. In both tests the alcohol is oxidized, and positive results are obtained in less than a minute. What would indicate a positive result? OBJ: Describe the connection between oxidant color and oxidation state of the metal ion. TOP: Chromium Oxides, Oxyanions, and Hydroxides 5. Assign formal charges to all atoms in the Lewis structure of the dichromate ion. Does the sum of the formal charges equal the charge on the ion?
OBJ: Assign formal charges to the atoms in the given Lewis structure. TOP: Formal Charge
Chapter 28—Some Nonmetals and Metalloids MULTIPLE CHOICE 1. Which noble gas is used in incandescent lights for home use? a. He b. Ne Whitten 10e
Test Bank
894
c. Ar d. Kr e. Xe ANS: C OBJ: Identify the noble gas used in incandescent lights for homes. TOP: Noble Gases – Occurrence, Uses, and Properties 2. Which noble gas can be dangerous when it escapes from the soil and collects in the basements of dwellings? a. Kr b. Ar c. Rn d. Ne e. Xe ANS: C OBJ: Identify the noble gas that poses a danger to some homeowners. TOP: Noble Gases – Occurrence, Uses, and Properties 3. Which of the following statements about noble gases is false? a. They are colorless, tasteless and odorless. b. Melting and boiling points increase with increasing atomic number. c. The attractive forces between their atoms include dipole-dipole interactions. d. Until the 1960's, chemists believed the noble gases were unable to react with other chemicals. e. They were formerly called "inert gases." ANS: C OBJ: Identify the incorrect description of the noble gases. TOP: Noble Gases – Occurrence, Uses, and Properties 4. Which one of the following pairs of noble gases and uses is not correctly matched?
a. b. c. d. e.
Noble Gas / Use xenon / mixed with krypton in high intensity flash tubes argon / inert atmosphere for welding helium / diluent for gaseous anesthetics neon / radiotherapy for cancerous tissues argon / filling incandescent light bulbs
ANS: D OBJ: Identify the incorrectly matched use and noble gas. TOP: Noble Gases – Occurrence, Uses, and Properties
Whitten 10e
Test Bank
895
5. Which statement regarding the noble gases is false? a. All fluorine compounds of the noble gases involve participation by the d orbitals of the noble gas atoms. b. Xenon will react with fluorine to form the colorless solids XeF2, XeF4, and XeF6. c. All of the xenon fluorides are formed in endothermic reactions. d. The oxidation state of xenon in Cs2XeF8 is +6. e. Oxygen compounds of xenon are known. ANS: C OBJ: Identify the incorrect description of noble gases. TOP: Xenon Compounds 6. Which one of the following compounds (apparently) involves sp3d3 hybridization at the xenon atom? a. XeO3 b. XeF2 c. XeF4 d. XeF6 e. XeO4 ANS: D OBJ: Identify the xenon compound with the given central atom hybridization. TOP: Xenon Compounds 7. What is the molecular geometry of XeF4? a. tetrahedral b. octahedral c. trigonal bipyramidal d. square planar e. square pyramidal ANS: D OBJ: Determine the molecular geometry given the formula TOP: Xenon Compounds 8. Which of the following does not correctly describe the halogen at room temperature and atmospheric pressure? a. fluorine / a pale yellow gas b. chlorine / a yellow-green gas c. bromine / a red-brown liquid d. iodine / a dark violet liquid e. astatine / a solid ANS: D OBJ: Identify the incorrect halogen description. TOP: Halogens – Properties 9. Which ion is not easily polarized by cations? a. F b. Cl c. Br d. I e. At ANS: A OBJ: Identify the halide ion not easily polarized by cations. TOP: Halogens – Properties Whitten 10e
Test Bank
896
10. Which halogen has the largest value for its electronegativity? a. astatine b. iodine c. bromine d. chlorine e. fluorine ANS: E OBJ: Identify the halogen with the largest electronegativity. TOP: Halogens – Properties 11. Which property of halogens decreases with increasing atomic weight? a. ionic radius b. melting point c. boiling point d. polarizability e. first ionization energy ANS: E OBJ: Identify the property of halogens that decreases with increasing atomic weight. TOP: Halogens – Properties 12. What is the oxidation number of chlorine in the compound potassium chlorate? a. 1 b. +1 c. +3 d. +5 e. +7 ANS: D OBJ: Calculate the oxidation number of element in a compound given the compound name. TOP: Halogens – Properties 13. Which of the following statements about halogens is false? a. The physical properties of the halogens differ significantly. b. They all exhibit the oxidation numbers 1,+1, +3, +5, and +7. c. The chemical properties of the halogens resemble each other closely. d. Many binary compounds that contain a metal and a halogen are ionic. e. In their outermost shell, all halogens have ns2np5 as their electron configuration. ANS: B OBJ: Identify the incorrect description of halogens. TOP: Halogens – Properties 14. Which halogen is the most important in terms of commercial use? a. fluorine b. chlorine c. bromine d. iodine e. astatine ANS: B OBJ: Identify the commercially most important halogen. TOP: Halogens – Occurrence, Production, and Uses
Whitten 10e
Test Bank
897
15. How many grams of chlorine gas are produced by the electrolysis of an aqueous NaCl solution in which 2.50 amperes of current are passed for 50.0 minutes? Recall Faraday's constant is 96500 C/mol electrons. a. 0.181 g b. 2.76 g c. 457 g d. 5.52 g e. 0.092 g ANS: B OBJ: Calculate the mass of chlorine produced by aqueous electrolysis given current and time. TOP: Halogens – Occurrence, Production, and Uses 16. Which of the following is the strongest oxidizing agent? a. Br2 b. Cl c. F2 d. F e. I2 ANS: C OBJ: Identify the strongest oxidizing agent. TOP: Halogens – Occurrence, Production, and Uses 17. What mass of fluorine is contained in two tons of cryolite that is 42.0% pure Na3AlF6? a. 912 lb b. 832 lb c. 456 lb d. 304 lb e. 152 lb ANS: A OBJ: Calculate the mass of an element given mass of sample and percent composition. TOP: Halogens – Occurrence, Production, and Uses 18. The density of liquid Br2 is 3.12 g/mL at 20.C. What volume of Br2 is produced at this temperature by the action of excess MnO2 on 250. g of KBr in the presence of H2SO4? 2KBr + MnO2 + 2H2SO4 Br2 + K2SO4 + MnSO4 + 2H2O a. b. c. d. e.
53.8 mL 80.7 mL 168 mL 424 mL 524 mL
ANS: A OBJ: Calculate the volume of a substance produced given the limiting reactant mass and the balanced reaction. TOP: Halogens – Occurrence, Production, and Uses
Whitten 10e
Test Bank
898
19. Which of the following occurs free in nature? a. F2 b. Cl2 c. Br2 d. I2 e. none of these ANS: E OBJ: Identify the halogen that occurs naturally. TOP: Halogens – Occurrence, Production, and Uses 20. Which halogen would react most rapidly with iron? a. Cl2 b. Br2 c. I2 d. F2 e. At2 ANS: D OBJ: Identify the most reactive halogen. TOP: Reactions of the Free Halogens 21. Which one of the following elements would react with chlorine most rapidly? a. Li b. Na c. K d. Rb e. Cs ANS: E DIF: Harder Question OBJ: Identify the most reactive metal. TOP: Reactions of the Free Halogens 22. What is the product of the reaction of fluorine and iron? a. FeF3 b. FeF c. FeF2 d. FeF6 e. no reaction occurs ANS: A DIF: Harder Question OBJ: Identify the product given the reactants. TOP: Reactions of the Free Halogens 23. Which one of the following does not correctly describe one or all of the hydrogen halides, HX? a. They are all colorless gases. b. HF exhibits hydrogen bonding. c. The order of increasing boiling points is HCl < HBr < HI < HF. d. Their aqueous solutions are acidic. e. Aqueous HF is the strongest hydrohalic acid.
Whitten 10e
Test Bank
899
ANS: E OBJ: Identify the incorrect description of the hydrogen halides. TOP: The Hydrogen Halides and Hydrohalic Acids 24. What mass of SiF4 could be produced by the reaction of 15 grams of SiO2 with an excess of HF? The equation for the reaction is SiO2 + 4HF SiF4 + 2H2O a. b. c. d. e.
1.04 g 12 g 26 g 104 g 8.7 g
ANS: C OBJ: Calculate the mass of product given the mass of limiting reactant and the balanced equation. TOP: The Hydrogen Halides and Hydrohalic Acids 25. Which statement about the production of HCl in the following reaction is false? H2 + Cl2 2HCl a. b. c. d. e.
The reaction does not occur significantly in the dark. The reaction occurs through a photochemical chain reaction. The reaction intermediates are radicals. The hydrogen chloride produced can react with H2O to produce chloric acid. As a dilute aqueous acid, HCl is considered a strong acid.
ANS: D OBJ: Identify the incorrect description of the production of HCl. TOP: The Hydrogen Halides and Hydrohalic Acids 26. Which of the following is the strongest acid? a. HCl b. HI c. HF d. HBr e. they are equally strong ANS: B OBJ: Identify the strongest acid. TOP: The Hydrogen Halides and Hydrohalic Acids 27. What is the effective bleaching and disinfecting agent in solutions of Cl2 or hypochlorite? a. Cl2 b. Cl c. HOCl d. H+ e. O radicals ANS: E OBJ: Identify the effective bleaching agent in solutions of chlorine and hypochlorite. TOP: The Oxoacids (Ternary Acids) of the Halogens
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Test Bank
900
28. Write and balance the formula unit equation for the reaction of chlorine with cold water. The sum of the coefficients in the balanced equation is ____. (Do not forget coefficients of one.) a. 6 b. 7 c. 8 d. 4 e. 5 ANS: D OBJ: Write a balanced equation given the reactants. TOP: The Oxoacids (Ternary Acids) of the Halogens 29. Which of these is the correct formula for sodium iodite? a. NaIO2 b. NaI c. NaIO d. NaIO4 e. NaIO3 ANS: A OBJ: Identify the formula given the compound name. TOP: The Oxoacids (Ternary Acids) of the Halogens 30. Calculate the percentage of bromine in Ca(BrO3)2. a. 24.6% b. 27.0% c. 31.2% d. 54.0% e. 62.4% ANS: D OBJ: Calculate the percent composition given a compound formula. TOP: The Oxoacids (Ternary Acids) of the Halogens 31. Which one of the Group VIA elements is the most different chemically from the other members of the group? a. O b. S c. Se d. Te e. Po ANS: A OBJ: Identify the element most different form the rest in the group. TOP: Occurrence, Properties, and Uses – S, Se, and Te 32. In what form does sulfur predominantly exist as a free element? a. S b. S2 c. S4 d. S8 e. S60
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Test Bank
901
ANS: D OBJ: Identify the predominant formula of sulfur. TOP: Occurrence, Properties, and Uses – S, Se, and Te 33. What is the largest and most important use of sulfur? a. production of sulfurous acid b. vulcanization of rubber c. prevention of pollution d. production of sulfuric acid e. synthesis of sulfur-containing organic compounds ANS: D OBJ: Identify the primary industrial use of sulfur. TOP: Occurrence, Properties, and Uses – S, Se, and Te 34. Which one of the following elements most commonly crystallizes in a brass-colored hexagonal crystal with a metallic luster? a. O b. S c. Se d. Te e. all VIA elements do ANS: D OBJ: Identify the element given a couple of physical properties. TOP: Occurrence, Properties, and Uses – S, Se, and Te 35. Which of the equations below does not represent a correct reaction of a VIA element? a. H2 + S H2S b. Se + 3F2 SeF6 c. 2S + Br2 S2Br2 d. Se2Cl2 + Cl2 2SeCl2 e. S + 2O2 SO4 ANS: E OBJ: Identify the incorrect chemical reaction of VIA elements. TOP: Reactions of Group 6A Elements 36. Write and balance the formula unit equation for the reaction of sulfur with nitric acid. What is the sum of the coefficients? (Two of the products are SO2 and NO. Represent sulfur as S. Do not forget coefficients of one.) a. 10 b. 12 c. 14 d. 16 e. 18 ANS: D DIF: Harder Question OBJ: Write a balanced reaction given the reactants and two of the products. TOP: Reactions of Group 6A Elements
Whitten 10e
Test Bank
902
37. Which of these is the strongest acid? a. H2O b. H2S c. H2Se d. H2Te e. none of these is an acid ANS: D OBJ: Identify the strongest acid. TOP: Hydrides of Group 6A Elements 38. Which statement about the Group VIA hydrides is false? a. H2S, H2Se, and H2Te are all gases at 25C and atmospheric pressure. b. All are colorless. c. All except H2O are toxic. d. The order of boiling points is H2O > H2S > H2Se > H2Te > H2Po. e. All are covalent compounds. ANS: D OBJ: Identify the incorrect description of Group VIA hydrides. TOP: Hydrides of Group 6A Elements 39. The hybridization at sulfur in SO2 is ____. a. sp b. sp2 c. sp3 d. sp3d e. sp3d2 ANS: B OBJ: Identify the hybridization of the central atom given the formula. TOP: Group 6A Oxides 40. A substance produced during the combustion of many fossil fuels is ____. a. S8 b. H2S c. SO2 d. S2Cl2 e. CuS ANS: C OBJ: Identify an important byproduct of fossil fuel combustion. TOP: Group 6A Oxides 41. Which of the following statements about SO2 and SO3 is false? a. If allowed to escape into the atmosphere, they cause acidic rain. b. SO3 is formed by the reaction of SO2 with O2. c. Both SO2 and SO3 are present in the flue gases when coal is burned. d. Scrubbing is a process that can remove all the SO2 and SO3 from flue gases. e. SO2 can be converted into SO3 and then dissolved in water to produce H2SO4. ANS: D REF: Identify the incorrect description of the some sulfur oxides. TOP: Group 6A Oxides
Whitten 10e
Test Bank
903
42. Which formula and name do not match?
a. b. c. d. e.
Formula / Name H2SeO3 / selenous acid TeF6 / tellurium hexafluoride H2S2O3 / "fuming sulfuric acid" NaHSO3 / sodium hydrogen sulfite H6TeO6 / telluric acid
ANS: C DIF: Harder Question OBJ: Identify the mismatched name and formula. TOP: Group 6A Oxides 43. Which statement regarding sulfuric acid is false? a. It is often used as a dehydrating agent because of its strong affinity for H2O. b. Concentrated sulfuric acid is about 78% H2SO4 by mass and 10 molar. c. It is a strong acid with respect to its first step ionization. d. Its second step ionization is not complete in concentrated solutions. e. It is often present in "acid rain". ANS: B OBJ: Identify the incorrect description of sulfuric acid. TOP: Oxoacids of Sulfur 44. What maximum mass of sulfuric acid can be produced from the sulfur contained in 100. kilograms of iron pyrite that is 75.0% FeS2? a. 84.4 kg b. 123 kg c. 136 kg d. 144 kg e. 168 kg ANS: B OBJ: Calculate the mass of sulfuric acid that can be produced from a sample given percent composition. TOP: Oxoacids of Sulfur 45. For selenic acid, H2SeO4, Ka1 is very large and Ka2 = 1.15 102. What is the pH of a 0.20 M H2SeO4 solution? a. 0.48 b. 0.55 c. 0.68 d. 0.75 e. 0.84 ANS: C DIF: Harder Question OBJ: Calculate the pH of a solution of diprotic acid given concentration and equilibrium constants. TOP: Oxoacids of Sulfur
Whitten 10e
Test Bank
904
46. Which one of the following is the most basic oxide? a. N2O3 b. P4O6 c. As4O6 d. Sb4O6 e. Bi2O3 ANS: E OBJ: Identify the most basic oxide. TOP: Occurrence of Nitrogen 47. In which one of the following is the oxidation state of nitrogen given incorrectly? a. H2N2O2; +1 b. HNO3; +5 c. N2H4; +2 d. N2O3; +3 e. NaNO2; +3 ANS: C OBJ: Identify the incorrect nitrogen oxidation state. TOP: Occurrence of Nitrogen 48. How many different oxidation states does nitrogen exhibit? a. 2 b. 3 c. 5 d. 6 e. more than 6 ANS: E OBJ: Identify the number of oxidation states exhibited by nitrogen. TOP: Occurrence of Nitrogen 49. The reaction of calcium nitride, Ca3N2, with water produces two basic compounds, one of which is a gas. Write the formula unit equation for the reaction. What is the sum of all coefficients? (Do not forget coefficients of one.) a. 8 b. 9 c. 10 d. 11 e. 12 ANS: E DIF: Harder Question OBJ: Write the balanced reaction given the reactants, number of products and a physical property of one of the products. TOP: Occurrence of Nitrogen 50. Which statement concerning nitrogen is false? a. Nitrogen is a colorless, odorless, tasteless gas. b. The high abundance of N2 in the atmosphere and the low relative abundance of nitrogen compounds elsewhere is due to the high chemical reactivity of N2. c. The bacteria in the root nodules of legumes convert N2 into NH3. d. Ammonia is the source of nitrogen in many fertilizers. e. The primary natural inorganic deposits of nitrogen are as KNO3 and NaNO3. Whitten 10e
Test Bank
905
ANS: B OBJ: Identify the incorrect description of nitrogen. TOP: Occurrence of Nitrogen 51. The ____ is the complex series of reactions by which nitrogen is slowly but continually recycled in the atmosphere, lithosphere and hydrosphere. a. nitrogen cycle b. nitrogen fixation c. nitrogen occurrence d. nitrogen mechanism e. nitrogen fertilization ANS: A OBJ: Identify the definition of the nitrogen cycle. TOP: Occurrence of Nitrogen 52. Ammonia can act as a(n) ____. I. Brønsted-Lowry base II. Arrhenius base III. Lewis base IV. solvent a. b. c. d. e.
I and II I, II, and III I, III, and IV II and III I, II, and IV
ANS: C OBJ: Identify all acid-base classifications that apply given the compound name. TOP: Hydrogen Compounds of Nitrogen 53. Which statement about amines is false? a. Amines are organic compounds that are structurally related to ammonia. b. All amines are weak bases. c. All amines have a lone pair (unshared pair) of electrons on the N atom. d. All amines involve an sp2-hybridized N. e. Amines can be considered as derived from NH3 by replacing one or more hydrogen atoms with organic groups. ANS: D OBJ: Identify the incorrect description of amines. TOP: Hydrogen Compounds of Nitrogen 54. Which one of the following statements about NO is false? a. It is paramagnetic. b. It is quite unreactive. c. It can be produced by internal combustion engines. d. It can be converted to NO2 in the air. e. It can be produced by combination of N2 and O2 in the presence of lightning. ANS: B OBJ: Identify the incorrect description of a nitrogen oxide. TOP: Nitrogen Oxides
Whitten 10e
Test Bank
906
55. Which compound gives photochemical smog a brownish color? a. NO b. HNO2 c. NO2 d. N2O4 e. N2O3 ANS: C OBJ: Identify the nitrogen oxide that is responsible for the brown color of smog. TOP: Nitrogen Oxides 56. According to the following equation, the volume of nitrogen (STP) required to produce 0.400 mol of NO is ____. N2 + O2 2NO a. b. c. d. e.
2.24 L 4.48 L 6.72 L 11.2 L 8.96 L
ANS: B OBJ: Calculate the volume of reactant given the moles of product and the balanced equation. TOP: Nitrogen Oxides 57. Consider the following statements about nitrogen dioxide. Which statement is false? a. Each NO2 molecule is a radical. b. NO2 readily dimerizes to form dinitrogen tetroxide. c. NO2 is prepared in the lab by heating heavy metal oxides. d. The molecule is linear. e. For the molecule NO2, nitrogen is in the +4 oxidation state. ANS: D OBJ: Identify the incorrect description of a nitrogen oxide. TOP: Nitrogen Oxides 58. Which statement about the oxoacids of nitrogen is false? a. Nitric acid is a strong acid and a strong oxidizing agent. b. Nitrous acid is a weak acid. c. Pure nitric acid is a liquid with a yellow or light brown color. d. Nitrous acid acts as an oxidizing agent toward strong reducing agents. e. Nitrous acid acts as a reducing agent toward very strong oxidizing agents. ANS: C OBJ: Identify the incorrect description of acidic nitrogen oxides. TOP: Some Oxoacids of Nitrogen and Their Salts 59. Which one of the following is used as a color preservative in meats? a. NH2Cl b. NaNO2 c. NH4Cl d. N2O4 e. Fe(NO3)3
Whitten 10e
Test Bank
907
ANS: B OBJ: Identify the meat color preservative. TOP: Some Oxoacids of Nitrogen and Their Salts 60. Which of the following statements about nitric acid is false? a. It is produced commercially by the Ostwald process. b. It is a strong acid. c. It is a weak oxidizing agent. d. The central nitrogen atom is sp2 hybridized. e. Nitric acid is very soluble in water. ANS: C OBJ: Identify the incorrect description of nitric acid. TOP: Some Oxoacids of Nitrogen and Their Salts 61. Potassium nitrate can be used as a fertilizer. Calculate the percentage of nitrogen in potassium nitrate. a. 8.46% b. 13.8% c. 16.5% d. 22.3% e. 26.2% ANS: B OBJ: Calculate the cent composition given the name of the compound. TOP: Some Oxoacids of Nitrogen and Their Salts 62. Given:
3Cu + 8HNO3 3Cu(NO3)2 + 2NO + 4H2O
What volume of NO (gas) at STP could be prepared by the reaction of 6.35 grams of Cu with an excess of HNO3? a. 1.49 L b. 2.24 L c. 4.48 L d. 6.72 L e. 0.746 L ANS: A OBJ: Calculate the volume of product given the mass of limiting reactant and the balanced equation. TOP: Some Oxoacids of Nitrogen and Their Salts 63. What is the major mineral present in phosphate rock? a. Ca3(PO4)2 b. NaH2PO4 c. Na2HPO4 d. Ca5(PO4)3(OH) e. Ca5(PO4)3F ANS: A OBJ: Identify the major mineral in phosphate rock. TOP: Phosphorus
Whitten 10e
Test Bank
908
64. The tips of "strike anywhere" matches contain two substances. One is red phosphorus; what is the other? a. white phosphorus, P4 b. calcium phosphate, Ca3(PO4)2 c. silica (sand), SiO2 d. tetraphosphorus trisulfide, P4S3 e. tetraphosphorus decoxide, P4O10 ANS: D OBJ: Identify a component of strike anywhere match tips. TOP: Phosphorus 65. What are the most stable forms of nitrogen and phosphorus at room temperature and atmospheric pressure? a. N2, P2 b. N, P4 c. N2, P4 d. N4, P2 e. N4, P4 ANS: C OBJ: Identify the most stable forms of nitrogen and phosphorus. TOP: Phosphorus 66. The compound P4O10 dissolves in water to form phosphoric acid as shown by the equation: P4O10 + 6H2O 4H3PO4 If 28.4 grams of P4O10 is dissolved in enough water to give 500. mL of solution, the resulting solution will be ____ molar in H3PO4. a. 0.100 b. 0.400 c. 0.800 d. 1.60 e. 0.200 ANS: C OBJ: Calculate the molarity of the product given the mass of limiting reactant, volume of solution, and the balanced equation. TOP: Phosphorus 67. What mass of Na3PO4 could be prepared by the reaction of 49.0 g of H3PO4 with 80.0 g of NaOH? H3PO4 + 3NaOH Na3PO4 + 3H2O a. b. c. d. e.
8.2 g 16.4 g 82.0 g 109 g 164 g
ANS: C OBJ: Calculate the mass of product given the mass of each reactant and the balanced equation. TOP: Phosphorus
Whitten 10e
Test Bank
909
68. Which of the following does not accurately describe elemental silicon? a. semiconductor b. shiny, blue-gray solid c. a brittle metalloid d. high melting point e. crystallizes in a graphite-like lattice ANS: E OBJ: Identify the incorrect description of silicon. TOP: Silicon and Silicates 69. Amethyst and agate are among the gems that consist of ____ with colored impurities. a. SiH4 b. SiF4 c. SiO2 d. Na2SiF6 e. Na6Si2O7 ANS: C OBJ: Identify the major component of certain gems. TOP: Silicon and Silicates 70. Which of the following statements concerning silicon and its bonding is false? a. Silicon does not form stable double bonds. b. Silicon does not form very stable SiSi bonds unless the silicon atoms are bonded to very electronegative elements. c. Silicon has vacant 3d orbitals in its valence shell that can accept electrons from donor atoms. d. Silicon forms its strongest single bond with oxygen. e. Silicon dioxide consists of linear molecules. ANS: E OBJ: Identify the incorrect description of silicon. TOP: Silicon and Silicates 71. Clay minerals generally have ____ structures with ____ surface areas. a. sheet-like; large b. sheet-like; small c. globular; large d. globular; small e. irregular; small ANS: A OBJ: Complete the description of clay minerals. TOP: Silicon and Silicates 72. Fused silicate glasses consist primarily of ____. a. K2SiO3 and Ag2SiO3 b. K2SiO3 and MgSiO3 c. Na2SiO3 and K2SiO3 d. CaSiO3 and MgSiO3 e. Na2SiO3 and CaSiO3
Whitten 10e
Test Bank
910
ANS: E OBJ: Identify the composition of fused silicate glasses. TOP: Silicon and Silicates 73. Asbestos is considered to be all of the following except? a. a fibrous material b. carcinogenic c. impure calcium silicate d. an inhalation hazard e. useful as fireproofing material ANS: C OBJ: Identify the incorrect description of asbestos. TOP: Silicon and Silicates 74. What volume of SiF4 (STP) can be obtained by the treatment of 100. grams of SiO2 with excess HF? SiO2 + 4HF SiF4 + 2H2O a. b. c. d. e.
26.6 L 34.6 L 37.3 L 39.2 L 42.4 L
ANS: C DIF: Harder Question OBJ: Calculate the volume of product given the mass of the limiting reactant and the balanced equation. TOP: Silicon and Silicates 75. Silicon is used for production of all of the following except: a. silicone polymers b. fertilizer c. transistors d. solar cells e. acid-resistant steels ANS: B OBJ: Identify the material that does not include silicon. TOP: Silicon and Silicates
Dynamic Questions 76. Based on the following data, what is the Cl-Cl bond energy? H2(g) + Cl2(g) HCl(g); H = –92.31 kJ Bond H-H H-Cl
Bond Energy (kJ/mol) 435 428
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Test Bank
911
a. b. c. d. e.
432 kJ/mol 236 kJ/mol –236 kJ/mol –421 kJ/mol 421 kJ/mol
ANS: B DIF: moderate OBJ: Determine the halogen bond energy. TOP: Halogens – Properties 77. What is the total number of valence electrons in NO? a. 11 b. 16 c. 17 d. 34 e. 15 ANS: A DIF: easy OBJ: Determine the number of valence electrons given the formula. TOP: Nitrogen Oxides 78. Which of the following reactions describes the formation of a covalent hydride? a. 2Rb(s) + H2(g) 2RbH(s) b. 2Li(s) + H2(g) 2LiH(s) c. Sr(s) + H2(g) SrH2(s) d. (s) + 6H2(g) (g) e. 2Al(s) + 3H2(g) 2AlH3(s) ANS: D DIF: easy OBJ: Identify the equation representing the formation of a covalent hydride. TOP: Hydrides of Group 6A Elements 79. What is the oxidation state of each nitrogen in molecular nitrogen? a. +2 b. 0 c. +3 d. +4 e. +5 ANS: B DIF: easy OBJ: Determine the oxidation state of nitrogen given the name of the compound. TOP: Compounds of Nitrogen 80. Which of the following occurs uncombined in nature?? a. P b. Cl c. S d. F e. Br Whitten 10e
Test Bank
912
ANS: C DIF: easy OBJ: Identify the element that occurs uncombined in nature. TOP: Element Occurrence 81. When an atom in a molecule or ion is described as sp hybridized, its electron geometry is a. linear. b. octahedral. c. trigonal bipyramidal. d. trigonal planar. e. tetrahedral. ANS: A DIF: easy OBJ: Match the geometry with the hybridization. TOP: VSEPR 82. What is the hybridization and molecular geometry of Xe in XeF2? hybridization / molecular geometry a. b. c. d. e.
sp3d / linear sp3d2 / linear sp3 / tetrahedral sp3d / square planar sp / linear
ANS: A DIF: easy OBJ: Identify the molecular geometry and hybridization of the central atom in a compound. TOP: Noble Gases – Occurrence, Uses, and Properties 83. What is the outer shell ground state electron configuration of F? a. 2s22p4 b. 3s23p5 c. 3s23p6 d. 2s22p5 e. 2s22p6 ANS: E DIF: easy OBJ: Identify the outer shell configuration of the halogen or halide. TOP: Halogens – Properties 84. Arrange the following in order of increasing ease of oxidation: At, I, Cl, Br a. At < Cl < Br < I b. Cl < I < At < Br c. At < Br < I < Cl d. Cl < Br < I < At e. Br < Cl < I < At ANS: D DIF: easy OBJ: Arrange the halides in order of increasing ease of oxidation. TOP: Halogens – Properties Whitten 10e
Test Bank
913
85. Which of the following do not contain sulfur? a. barite b. cinnabar c. cryolite d. galena e. volcanic gases ANS: C DIF: moderate OBJ: Identify the substance that does not contain sulfur. TOP: Occurrence, Properties, and Uses – S, Se, and Te 86. Based on your knowledge of electronic structure and periodic trends, which of the following
elements has the 2s orbital with the highest energy? a. boron b. carbon c. nitrogen d. oxygen
e. fluorine
ANS: A OBJ: Identify the element with the highest energy 2s orbital. TOP: General Characteristics of Nonmetals 87. Based on your knowledge of electronic structure and periodic trends, which of the following
elements would most easily lose 2s electrons? a. boron b. carbon c. nitrogen
d. oxygen
e. fluorine
ANS: A OBJ: Identify the element that easily loses 2s electrons. TOP: General Characteristics of Nonmetals 88. Which of the following are characteristics of main-group non-metals? a. are located on the left and towards the bottom of the periodic table b. have low first ionization energies c. have high first ionization energies d. have high effective nuclear charge e. two of the above ANS: E OBJ: Identify the common characteristics of nonmetals. TOP: General Characteristics of Nonmetals
Consider the model of a borate ion below, in which all of the bonds are single bonds, all of the oxygen, O, atoms have 2 lone pairs, and there are no lone pairs on boron, B, to answer the following questions:
Whitten 10e
Test Bank
914
89. What is the oxidation number of each boron atom? a. 0 b. +1 c. +2 d. +3
e. +4
ANS: D OBJ: Determine the oxidation number of the specified element. TOP: Oxidation Number 90. What is the overall charge of the borate ion shown above? a. +1 b. -1 c. +2 d. -2
e. -3
ANS: D OBJ: Determine the net charge of the ion. TOP: Formal Charge
Consider the model of a borate ion below to answer the following questions:
91. What is the formal charge on the boron atoms? a. 0 b. +1 c. +2
d. +3
e. +4
92. What is the formal charge on the terminal oxygen atoms? a. 0 b. +1 c. -1 d. -2
e. -3
ANS: D OBJ: Determine the element formal charge. TOP: Formal Charge
ANS: C OBJ: Determine the element formal charge. TOP: Formal Charge 93. What is the formal charge on the central oxygen atom? a. 0 b. +1 c. -1 d. -2
e. -3
ANS: A OBJ: Determine the element formal charge. TOP: Formal Charge CONCEPTUAL 1. How would life on earth be different if nitrogen gas were not such a stable compound? OBJ: Describe a world in which nitrogen is not so stable. TOP: Occurrence of Nitrogen
Whitten 10e
Test Bank
915
2. Consider the diatomic halogen molecules. Explain why as you progress down the periodic table, these diatomic molecules change from gas to liquid to solid at room temperature. OBJ: Explain the progression of gas to liquid to solid of the halogens. TOP: Halogens – Properties 3. Explain why, over the last decade or two, many states have enacted regulations about which kinds of coal can be burned in power plants. OBJ: Discuss the grades of coal and their effect on the environment when burned. TOP: Oxoacids of Sulfur | Fossil Fuels 4. Why were the noble gases among the last elements (besides the manmade elements) to be discovered? Do they occur naturally in compounds from which they could be isolated? Why or why not? OBJ: Explain the occurrence of noble gases on earth and why they were the last elements to be discovered. TOP: Noble Gases – Occurrence, Uses, and Properties 5. The xenon compound XeF6 apparently has sp3d3 hybridization. Using your knowledge of VSEPR theory, estimate the geometry and bond angles for the electron pairs that surround the xenon atom. OBJ: Determine the central atom electron geometry of a noble gas compound given the hybridization and formula. TOP: VSEPR
Whitten 10e
Test Bank
916