C2 h revision pack 2015 by Isaac Newton Academy

Chemistry Unit C2 Discovering Chemistry Study and Revision Pack (Higher)

Contents C2 Topic 1 ........................................................................................................................................ 2 Specification Statements .............................................................. Error! Bookmark not defined. C2 Topic 1 Exam Questions ......................................................... Error! Bookmark not defined. C2 Topic 2 ........................................................................................................................................ 7 Specification Statements .............................................................. Error! Bookmark not defined. C2 Topic 2 Exam Questions ......................................................... Error! Bookmark not defined. C2 Topic 3 ...................................................................................................................................... 13 Specification Statements .............................................................. Error! Bookmark not defined. C2 Topic 3 Exam Questions ......................................................... Error! Bookmark not defined. C2 Topic 4 ...................................................................................................................................... 16 Specification Statements .............................................................. Error! Bookmark not defined. C2 Topic 4 Exam Questions ......................................................... Error! Bookmark not defined. C2 Topic 5 ...................................................................................................................................... 21 Specification Statements .............................................................. Error! Bookmark not defined. C2 Topic 5 Exam Questions ......................................................... Error! Bookmark not defined. C2 Topic 6 ...................................................................................................................................... 29 Specification Statements .............................................................. Error! Bookmark not defined. C2 Topic 6 Exam Questions ......................................................... Error! Bookmark not defined.

C2 Topic 1 Atomic Structure and the Periodic Table 46 marks 46 minutes

Q1. The positions of five elements, A, B, C, D and E, are shown in the periodic table. These letters are not the atomic symbols of these elements.

(a) Use only elements A, B, C, D and E to answer (i) and (ii). (i) Give the letters of all the elements that are metallic. (1) .............................................................................................................................................. (ii) Give the letters of the two elements that have the most similar chemical properties. (1) .............................................................................................................................................. (b) An atom of element B contains more protons than an atom of element A. State how many more protons there are in an atom of element B than in an atom of element A. (1) .............................................................................................................................................. (c) An atom of element E has atomic number 10 and mass number 22. (i) How many electrons does this atom contain? Put a cross ( ) in the box next to your answer. (1) A 10 B 12 C 22 D 32 (ii) 10% of the atoms in a sample of element E have a mass number of 22. All the other atoms in this sample have a mass number of 20. Calculate the relative atomic mass of element E. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. relative atomic mass = . . . . . . . . . . . . . . . . . . . . . . (d) The element below E in the periodic table is used to fill filament light bulbs. Explain why this element is suitable for this use. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. 2

(Total for Question is 9 marks) Q2. (a) The table shows the number of electrons, neutrons and protons in particles P, Q, R, S, T and V.

(i) Which particle is a negatively charged ion? Put a cross ( ) in the box next to your answer. A P B S C T D V (ii) Which particles are atoms of metals? Put a cross ( ) in the box next to your answer.

(1)

(1) A P and R B Q and R C Q and S D Q, S and V (b) Each element has an atomic number. (i) State what is meant by atomic number. (1) .............................................................................................................................................. .............................................................................................................................................. (ii) The atomic number of boron is 5. Boron exists as two isotopes boron-10 and boron-11. Use this information to explain why boron-10 and boron-11 are isotopes. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (c) (i) Explain what is meant by the term relative atomic mass. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) A sample of boron contains 19.7% of boron-10. 80.3% of boron-11. Use this information to calculate the relative atomic mass of boron. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ................................................................................................(Total for Question = 10 marks) 3

Q3. Metal atoms The table shows some information about four metals. metal

atomic number

lithium 3 sodium 11 magnesium 12 calcium 20 (a) State the electronic configuration of sodium.

electronic configuration 2.1 2.8.2 2.8.8.2

(1) .............................................................................................................................................. (b) Magnesium and calcium are in the same group of the periodic table. Explain why they are both in the same group. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (c) Complete the sentence by putting a cross ( ) in the box next to your answer. The atomic number of an element is equal to the number of (1) A neutrons in the nucleus of its atom B electrons in the nucleus of its atom C protons in the nucleus of its atom D protons and neutrons in the nucleus of its atom (d) Which of these statements is correct about the particles in atoms? Put a cross ( ) in the box next to your answer. (1) A a proton has the same mass as an electron B an electron is heavier than a proton C a neutron is lighter than an electron D a neutron has the same mass as a proton (e) A lithium atom contains charged particles and yet the atom has no overall charge. Explain why. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

Q4. Boron exists as two isotopes. These are boron-10, 105B, and boron-11, 115B. (a) The diagram shows an atom of the isotope, boron-10.

(i) State the electronic configuration of boron. (1) .............................................................................................................................................. (ii) Complete the sentence by putting a cross ( ) in the box next to your answer. In the periodic table, boron is in period (1) A 2 B 3 C 5 D 10 (iii) The table shows the three particles present in atoms and their relative masses and charges. Complete the table. (2) particle

relative mass

relative charge

electron neutron proton +1 *(b) A sample of boron contains 20% boron-10 and 80% boron-11. In part (a) you were given the structure of a boron-10 atom. Describe the structure of a boron-11 atom and explain why, in this sample, boron has a relative atomic mass of 10.8. (6) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. 5

(c) Mendeleev was a Russian chemist who produced the first version of the periodic table. Give one similarity and one difference between his version of the periodic table and the periodic table shown on page 2. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (2) (Total for Question is 12 marks) Q5. Lithium, sodium and potassium are metals in group 1 of the periodic table. They are good conductors of heat and electricity. The freshly-cut metals are shiny. (a) (i) Give another physical property of all three of these metals. (1) .............................................................................................................................................. (ii) Explain, in terms of electrons in their atoms, why lithium, sodium and potassium are in group 1 of the periodic table. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) A small piece of potassium is added to water. (i) Describe what you would see in this reaction. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) Which of these is the balanced equation for this reaction? Put a cross ( ) in the box next to your answer. (1) A 2K + 2H2O K2O + 2H2 B 2K + H2O K2O + H2 C 4K + 3H2O 4KOH + H2 D 2K + 2H2O 2KOH + H2 (c) There is an increase in reactivity of these group 1 metals from lithium to potassium. Explain this increase in reactivity. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 8 marks)

C2 Topic 2 Ionic Compounds and Analysis 53 marks 53 minutes Q1. The table shows some properties of six compounds. compound

melting point / °C

boiling point / °C

solubility in water

copper sulfate

200

decomposes

soluble

hexane

–95

insoluble

hydrogen chloride

–112

–85

soluble

octane

–57

126

insoluble

electrical conductivity of solution high does not dissolve high does not dissolve does not dissolve

silicon(IV) 1610 2230 insoluble oxide sodium 801 1413 soluble high chloride (a) Which of the following lists of compounds from the table contains only ionic compounds? Put a cross ( ) iin the box next to your answer. (1) A B C D

copper sulfate, octane and sodium chloride silicon(IV) oxide and sodium chloride copper sulfate and sodium chloride copper sulfate and silicon(IV) oxide

(b) Two of the compounds in the table produce a colour in a flame test. Give the name of one of these compounds and the colour it produces in the flame test. (2) compound . . . . . . . . . . . . . . . . . . . . colour . . . . . . . . . . . . . . . . . . . . (c) Hexane is a covalent compound containing simple molecules. It has a low boiling point. (i) Explain why it has a low boiling point. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) Hexane and water are immiscible. Describe how separate samples of hexane and water can be obtained from a mixture of hexane and water. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (d) Draw a dot and cross diagram of a molecule of hydrogen chloride. Show outer electrons only. (2)

(Total for Question is 9 marks) Q2. (a) The table shows the names and formulae of three ions. name of ion calcium nitrate phosphate What is the formula of calcium nitrate? Put a cross ( ) in the box next to your answer.

formula of ion Ca2+ NO3â&#x20AC;&#x201C; PO43â&#x20AC;&#x201C; (1)

A Ca2NO3 B CaNO3 C Ca3NO2 D Ca(NO3)2 (b) Complete the sentence by putting a cross ( ) in the box next to your answer. The number of oxygen atoms in the formula Ca3(PO4)2 is A B C D

2 4 8 12

(1)

Sodium sulfide is an ionic compound. Describe, in terms of electron transfer, how sodium atoms react with sulfur atoms to form sodium sulfide. Your description should include the charges on the ions formed. (4) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. *(d) Explain the difference in the ability of solid sodium chloride and molten sodium chloride to conduct electricity in terms of their structures. (6) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 12 marks)

Q3. Sodium carbonate and copper chloride are both ionic solids. They are both soluble in water. (a) Which row of the table shows the most likely melting points of these two salts? Put a cross ( ) in the box next to your answer. (1) melting point / Â°C sodium carbonate copper chloride A 17 498 B 851 9 C 851 498 D 9 17 2+ (b) Copper chloride contains copper ions, Cu , and chloride ions, Clâ&#x20AC;&#x201C;. Give the formula of copper chloride. (1) .............................................................................................................................................. (c) Complete the sentence by putting a cross ( ) in the box next to your answer. If a flame test is carried out on copper chloride, the colour in the flame is (1) A red-brown B yellow C lilac D green-blue (d) Describe how this apparatus can be used to show that sodium carbonate reacts with dilute acid to form carbon dioxide. (3)

.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (e) Copper carbonate is an insoluble salt. Describe how you would use sodium carbonate and copper chloride to produce a pure, dry sample of copper carbonate. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 9 marks) 10

Q4. Salts The table gives the names and formulae of three salts.

(a) The atomic number of calcium, Ca, is 20. A calcium cation has the symbol Ca2+. How many electrons does a calcium cation contain? (1) .............................................................................................................................................. (b) The symbol for a sodium cation is Na+. What is the symbol for a carbonate ion? (1) .............................................................................................................................................. (c) Calcium chloride is an ionic solid. It has a high melting point of 782 째C. Explain why calcium chloride has a high melting point. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. *(d) Choose one of the three salts from the table. Describe, using suitable tests, how you would confirm the identity of each of the two ions in the salt you have chosen. (6) Name of salt .................................................................................................................................... Description of your tests ................................................................................................................ .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

Q5. (a) Sodium chloride is a metal chloride which is soluble in cold water. (i) Give the name of a metal chloride which is insoluble in cold water. Put a cross ( ) in the box next to your answer. (1) A copper chloride B lead chloride C magnesium chloride D potassium chloride (ii) Sodium chloride has a melting point of 801 째C. Explain why the melting point of sodium chloride is high. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (iii) Describe how you would test for the presence of chloride ions in a solution of sodium chloride. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. *(b) Magnesium has an electronic configuration of 2.8.2. Oxygen has an electronic configuration of 2.6. Explain, in terms of their electronic configurations, how magnesium and oxygen atoms react to form the ionic compound magnesium oxide, MgO, and include a description of the structure of solid magnesium oxide. (6) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question = 12 marks)

C2 Topic 3 Covalent Compounds and Separation Techniques 26 marks 26 minutes Q1. Nitrogen and oxygen are present in the air. (a) In industry, nitrogen and oxygen are obtained from air. (i) Give the name of the process used. (1) .............................................................................................................................................. (ii) State why the air is cooled before the start of the process. (1) .............................................................................................................................................. .............................................................................................................................................. (b) Complete the sentence by putting a cross ( ) in the box next to your answer. Oxygen has a low boiling point because there are (1) A weak covalent bonds between the oxygen atoms B weak covalent bonds between the oxygen molecules C weak forces of attraction between the oxygen atoms D weak forces of attraction between the oxygen molecules (c) Another gas present in air is carbon dioxide, CO2. There are covalent bonds between the atoms in a molecule of carbon dioxide. (i) Describe what is meant by a covalent bond. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) The electronic configuration of oxygen (atomic number 8) is 2.6. Give the electronic configuration of carbon (atomic number 6). (1) .............................................................................................................................................. (iii) Draw a dot and cross diagram of a molecule of carbon dioxide. Show outer electrons only. (2)

(Total for Question = 8 marks)

Q2. (a) Complete the sentence by putting a cross ( ) in the box next to your answer. A mixture of two immiscible liquids can be separated by using (1) A fractional distillation B a separating funnel C evaporation D filtration (b) Oxygen is a simple molecular, covalent substance. (i) The electronic configuration of oxygen is 2.6. Draw a dot and cross diagram for a molecule of oxygen, O2. Show the outer electrons only. (3)

(ii) The boiling point of oxygen is â&#x20AC;&#x201C;183 Â°C. Explain, in terms of the forces between the molecules, why oxygen has a very low boiling point. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (c) Describe how oxygen and nitrogen are obtained from liquid air by fractional distillation. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 9 marks) Q3. Structures The table shows some properties of diamond and graphite. diamond

graphite

colourless crystals black, shiny solid very hard flakes easily does not conduct electricity conducts electricity (a) (i) Suggest why diamond and graphite might be expected to have similar properties. (1) .............................................................................................................................................. .............................................................................................................................................. (ii) By referring to its structure, explain why diamond is very hard. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. 14

.............................................................................................................................................. (iii) By referring to its structure, explain why graphite flakes easily. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) Complete the sentence by putting a cross ( ) in the box next to your answer. Carbon dioxide is a gas at room temperature. A carbon dioxide molecule is a (1) A giant molecule that has covalent bonds B giant molecule that has ionic bonds C simple molecule that has covalent bonds D simple molecule that has ionic bonds (c) The atomic number of carbon is 6 and of fluorine is 9. Carbon and fluorine atoms are combined in a tetrafluoromethane molecule, CF4. Draw a dot and cross diagram of a tetrafluoromethane molecule. Show outer electrons only. (2)

C2 Topic 4 Groups in the Periodic Table 28 Marks 28 Minutes

Q1. Lithium, sodium and potassium are metals in group 1 of the periodic table. They are good conductors of heat and electricity. The freshly-cut metals are shiny. (a) (i) Give another physical property of all three of these metals. (1) .............................................................................................................................................. (ii) Explain, in terms of electrons in their atoms, why lithium, sodium and potassium are in group 1 of the periodic table. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

(b) A small piece of potassium is added to water. (i) Describe what you would see in this reaction. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) Which of these is the balanced equation for this reaction? Put a cross ( ) in the box next to your answer. (1) A 2K + 2H2O K2O + 2H2 B 2K + H2O K2O + H2 C 4K + 3H2O 4KOH + H2 D 2K + 2H2O 2KOH + H2 (c) There is an increase in reactivity of these group 1 metals from lithium to potassium. Explain this increase in reactivity. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 8 marks) Q2. (a) Two pieces of metal can be joined by welding them together.

(i) Complete the sentence by putting a cross ( The structure of a metal is a lattice of

) in the box next to your answer. (1)

A anions B anions and cations C cations in a sea of electrons D molecules in a sea of electrons (ii) To join two pieces of metal by welding, they must be melted together. State why a high temperature has to be used. (1) .............................................................................................................................................. .............................................................................................................................................. 17

(iii) The pieces of metal are welded together in an atmosphere of argon. Explain why an atmosphere of argon is used. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) Some metals react with halogens. Iron reacts with bromine, Br2, to form iron(III) bromide, FeBr3. Write the balanced equation for this reaction. (2) .............................................................................................................................................. (c) Complete the sentence by putting a cross ( ) in the box next to your answer. At room temperature, iodine is a (1) A brown gas B brown liquid C grey solid D purple gas (d) When a halogen is added to a solution containing halide ions a displacement reaction may occur In the table shows a displacement reaction occurs shows a displacement reaction does not occur

Use the information in the table to explain the order of reactivity of the three halogens. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question = 9 marks)

Q3. Sodium The picture shows sodium metal reacting with chlorine gas to produce solid sodium chloride.

(a) (i) Draw one straight line from each element to the part of the periodic table in which it is found. (2)

(ii) Write a balanced symbol equation for the reaction of sodium with chlorine, Cl2.

(2) .............................................................................................................................................. (iii) Complete the sentence by putting a cross ( ) in the box next to your answer. Sodium chloride does not conduct electricity when solid but it does conduct electricity when molten. It has a very high melting point. The structure of sodium chloride is (1) A ionic B simple molecular, covalent C giant molecular, covalent D metallic (b) Sodium metal is stored under oil. Explain why it is stored in this way. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. 19

atomic number

lithium 3 sodium 11 potassium 19 rubidium 37 caesium 55 francium 87 Elements in group 1 increase in reactivity as their atomic numbers increase. Explain why. (4) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

C2 Topic 5 Chemical Reactions 51 Marks 51 Minutes

Q1. (a) An experiment is carried out to measure the temperature change when solid ammonium chloride is dissolved in water. initial temperature of water = 19째C final temperature of solution = 15째C Explain what the temperature readings show about the type of heat change occurring when ammonium chloride dissolves in water. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) When zinc reacts with copper sulfate solution, copper and zinc sulfate solution are formed. Zn + CuSO4

Cu + ZnSO4

This reaction is exothermic. Use this information to complete the diagram. (2)

(c) Reactions are accompanied by heat changes. The heat changes are the results of bonds being broken and bonds being formed. Which row of the table shows the heat energy changes that occur when bonds are broken and when bonds are formed? Put a cross ( ) in the box next to your answer. (1)

*(d) Reactions can occur when particles collide. Rates of reactions can be altered by changing conditions. Explain how the rate of reaction between a solid and a liquid is altered by changing the size of the pieces of solid and by changing the temperature of the liquid. (6) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 11 marks)

Q2. A student investigated the rate of a reaction. The student investigated the reaction between zinc and dilute sulfuric acid. The products are zinc sulfate, ZnSO4, and hydrogen. (i) Write the balanced equation for this reaction. (2) .............................................................................................................................................. *(ii) The student carried out two experiments. The same mass of zinc and the same sized pieces of zinc were used in each experiment. The results are shown in the table.

Evaluate these results, explaining the reasons why the rate of reaction in experiment 2 is faster than the rate of reaction in experiment 1. In your answer you should refer to the frequency and energy of collisions between particles. (6) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

Q3. (a) Zinc is a metal. Zinc reacts with dilute hydrochloric acid to produce zinc chloride and hydrogen. Edward used this apparatus to investigate the speed of the reaction between zinc and dilute hydrochloric acid.

(i) Edward's results for 50 째C are shown on the graph.

Sketch a line on the graph to show the results that Edward should expect to obtain if he carried out the experiment to completion at 30 째C. (2) (ii) When zinc powder is used, instead of larger pieces of zinc, the reaction is faster. Explain, using ideas about particles, why the reaction is faster when zinc powder is used. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

(iii) Balance the equation for the reaction of zinc with dilute hydrochloric acid by putting a number in the space provided. (1) Zn + . . . . . . . . . . . . . HCl â&#x2020;&#x2019; ZnCl2 + H2 (iv) The reaction between zinc and dilute hydrochloric acid is exothermic. Explain, in terms of breaking and forming bonds, why this reaction is exothermic. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) Catalysts are added to some reactions. State the effect of catalysts on reactions. (1) .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 9 marks) Q4. (a) A student investigated the rate of a reaction. The student investigated the reaction between zinc and dilute sulfuric acid. The products are zinc sulfate, ZnSO4, and hydrogen. (i) Write the balanced equation for this reaction. (2) .............................................................................................................................................. *(ii) The student carried out two experiments. The same mass of zinc and the same sized pieces of zinc were used in each experiment. The results are shown in the table.

(b) Zinc is reacted with copper sulfate solution. The equation for the reaction is Zn(s) + CuSO4(aq) â&#x2020;&#x2019; ZnSO4(aq) + Cu(s) (i) What type of reaction is this? (1) Put a cross ( ) in the box next to your answer. A decomposition B displacement C dissolving D neutralisation (ii) This reaction is exothermic. On the diagram below draw labelled lines to show the relative energies of the reactants and products in this reaction. (2)

(Total for Question = 11 marks)

Q5. Calcium carbonate (a) Calcium carbonate reacts with dilute hydrochloric acid. Complete the sentence by putting a cross ( ) in the box next to your answer. In this reaction hydrochloric acid is (1) A precipitated B displaced C neutralised D combusted (b) The equation for the reaction is

The diagram shows the heat energy contained in the reactants and the heat energy contained in the products.

Use the diagram to explain why this reaction is as an exothermic reaction. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (c) If dilute hydrochloric acid is heated before calcium carbonate is added, the rate of reaction increases. Explain, in terms of particles, why the rate of reaction increases. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

*(d) An experiment was carried out to compare the rates of reaction between calcium carbonate and two different concentrations of hydrochloric acid. Describe, in detail, how you would carry out this experiment. (6) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

C2 Topic 6 Quantitative Chemistry 40 Marks 40 Minutes

Q1. (a) Calcium oxide is manufactured by heating calcium carbonate. The waste product of this process is carbon dioxide. (i) Calculate the relative formula mass of carbon dioxide, CO2. (Relative atomic masses: C = 12, O = 16) (1) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) The equation for the reaction is CaCO3(s) â&#x2020;&#x2019; CaO(s) + CO2(g) Calculate the maximum mass of calcium oxide that can be obtained by heating 25 tonnes of calcium carbonate. (Relative atomic masses: C = 12, O = 16, Ca = 40) (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) (i) State what is meant by theoretical yield. (1) .............................................................................................................................................. .............................................................................................................................................. (ii) Explain why the actual yield for a reaction is usually less than the theoretical yield for the reaction. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (c) Many industrial processes produce waste products. Suggest reasons why manufacturers try to find uses for these waste products. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 9 marks)

Q2. The diagram shows a piece of magnesium ribbon being heated.

During the heating, the magnesium reacts with oxygen from the air. The lid of the crucible was raised slightly from time to time. Magnesium oxide was formed as a white powder. The experiment was repeated with different masses of magnesium. The table shows the mass of magnesium used and the mass of the magnesium oxide formed in each experiment.

experiment

mass of magnesium used /g

mass of magnesium oxide formed /g

mass of oxygen in magnesium oxide /g

1 0.10 0.16 0.06 2 0.15 0.24 0.09 3 0.25 0.40 0.15 4 0.30 0.48 0.18 5 0.35 0.49 0.14 6 0.50 0.80 0.30 (a) Suggest why the lid had to be raised from time to time during the experiment. (1) .............................................................................................................................................. ..............................................................................................................................................

(b) (i) On the grid provided, draw a graph of the mass of oxygen in magnesium oxide against the mass of magnesium used. (3)

(ii) The result of experiment 5 is anomalous. The masses were all measured accurately. Suggest what might have caused this anomalous result. (1) .............................................................................................................................................. .............................................................................................................................................. (c) Write the balanced equation for the reaction of magnesium with oxygen to form magnesium oxide. (3) .............................................................................................................................................. (d) An oxide of lead was analysed. 0.414 g of lead was combined with 0.064 g of oxygen in this oxide. Calculate the empirical formula of this lead oxide. (relative atomic masses: O = 16, Pb = 207) (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question is 11 marks)

Q3. In industry sodium carbonate is made from sodium chloride solution and calcium carbonate in the Solvay Process. (a) Describe the test to show that calcium carbonate contains carbonate ions. (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (b) Another product of the Solvay Process is calcium chloride. Calculate the relative formula mass of calcium chloride, CaCl2. (Relative atomic masses: Ca = 40; Cl = 35.5) (1) .............................................................................................................................................. .............................................................................................................................................. (c) The overall equation for the Solvay Process is 2NaCl + CaCO3 â&#x2020;&#x2019; Na2CO3 + CaC2 Calculate the maximum mass of sodium carbonate that could be formed by reacting 40 kg of calcium carbonate with an excess of sodium chloride solution. (Relative formula masses: CaCO3 = 100; Na2CO3 = 106)

(2)

.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (d) Sodium carbonate was made in a laboratory experiment. The theoretical yield of the experiment was 15.0 g. The actual yield of the experiment was 10.4 g. (i) Calculate the percentage yield of sodium carbonate in this experiment. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) Suggest two reasons why the actual yield was less than the theoretical yield. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (Total for Question = 10 marks)

Q4. Copper and its compounds (a) Copper is a transition metal. Which of these is a property of copper? Put a cross ( ) in the box next to your answer. (1) A it is a poor conductor of electricity B it is brittle C it has a low melting point D it forms coloured compounds (b) Jasmine reacted an oxide of copper with carbon. copper oxide + carbon → copper + carbon dioxide She reacted 5.0 g of copper oxide. In her reaction, 2.8 g of copper was formed. The theoretical yield for this reaction is 4.0 g. (i) State what is meant by the term theoretical yield. (1) .............................................................................................................................................. .............................................................................................................................................. (ii) The percentage yield of Jasmine’s experiment was 70%. Explain how this value was calculated. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (iii) State two reasons why the yield of Jasmine’s experiment was not 100%. (2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (c) Calculate the relative formula mass of copper chloride, CuCl2. (Relative atomic masses: Cu = 63.5, Cl = 35.5) (1) .............................................................................................................................................. .............................................................................................................................................. answer = ................................................................ (d) 14.3 g of an oxide of copper contained 12.7 g of copper. Calculate the empirical formula of this oxide. Show your working. (Relative atomic masses: Cu = 63.5, O = 16) (3) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. answer = .........................................................................