Data
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In this chapter we will be looking at data. We will begin by designing and performing a Mentos Eruption Experiment, and will investigate throughout the week how to use the data that is obtained in a clear and meaningful way.
The tentative schedule for this unit is:
Day 1,2: Design Mentos Experiment. SI Units. Prefixes. Derived Units. Density. Temperature. Homework: Bring in mentos, soda and any other experimental aids Long term project: Research, outline Mentos Experiment Report- due:_______ Day 2: Initial Mentos Experiments. Scientific Notation (L1 only). Unit Conversions Homework: __________ Bring in additional mentos experiment supplies. Long term project: Continue writing Mentos Experiment Report- due ____________ Day 3: Final Mentos Experiments. Significant Figures (L1 only). Percent Error Bring in additional mentos experiment supplies. Long term project: Continue writing Mentos Experiment Report- due ____________ Day 4: Videotaped Mentos Performances. Review for Units 1 and 2 Test (Intro to chem, data) Homework: Complete How to Ace the Units 1 and 2 test. Review for Units 1 and 2 test Day 5: Test: Introduction to Chemistry and Data. Watch videotaped mentos performances Possible In-class time to continue writing Mentos Experiment Reports- due __________.
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Name_________________________
Period__________
Lab2.1
Mentos Eruption Experiment 30 Points
Recently you observed the Mentos Eruption demonstration. In that demonstration, Mentos candies were added to soda, resulting in a violent eruption. Hopefully the demonstration made you wonder about what was going on during the demonstration. What causes the eruption? Does it have to be Diet Coke? Would more Mentos make the fountain go even higher? Would another type of candy work? Well this is your chance to answer those questions. Design an experiment based on your question, and you and your partner will perform it in class. Try to be creative- come up with an experiment that no one else is thinking of. 1. Effect of mentos temperature on the height of a mentos eruption Will an ice-cold mentos make for a really big eruption?? 2. Effect of soda temperature on the height of a mentos eruption -what would happen with near-frozen soda?? 3. Design of a remote-control mentos eruption -can you do create a remote control method? 4. Effect of nozzle size on the height of a mentos eruption -this can make for awesome special effects…think of fancy sprinklers 5. Design of a delayed mentos eruption -a tough one…it would work like a fuse…very safe 6. Effect of gum arabic on the height of a mentos eruption -everyone says its due to gum Arabic, but no one has ever tried it. 7. Determination of % CO2 using a mentos eruption -there must be a nice correlation 8. Effect of surface coating on the height of a mentos eruption -coat your mentos with something to double the height 9. Effect of nucleation sites on the height of a mentos eruption -I am so skeptical of this whole theory…I’ll bet it can be diproved 10. Effect of soda type on the height of mentos eruption -maybe there is a special soda out there 11. Pendulum effects based on the mentos eruption -and other eepy-bird type fun designs…makes for great video…perhaps a class performance is possible. 12. Mentos surface investigation Microscopic imaging has never been performed…Enhancement might be possible…An etched mento? Conceptual Chemistry Classes will demonstrate and video tape their final experiments. You will be graded equally on 1. Significance- did you discover anything new? Is your device or system useful? 2
2. Presentation- was your presentation to the class clear? Nicely rehearsed? Fun to watch? Is everyone clear what you are doing and why? 3. Awareness- has your experiment been done before? How do you explain your results? How does your device work? Level One Only: Your results will be published in The Guilford Journal of Chemistry; each of you will receive the most recent publication. Read it, and use it as a guide to determine your own experiments. Note that as for all scientific research, you must produce new and significant scientific results to be considered for publication in this journal. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Level One Only: The typed Journal report is due on the date specified. There will be a 10% deduction for each late day. The format is that of a typed scientific journal research article. Use the most recent Journal to assist you. You will be graded on the content in 10 areas: 1. Title 2 Your names. 3. A one paragraph summary of your experiment and results. 4. An introduction that summarizes what is known in your research area, with footnoted references. Use quality references such as that in previous Journal voumes. 5. An experimental section that briefly describes your experiment. If your experiment is design-based, (for example the design of a remote control system) each iteration can be described here 6. A results section. This must include a graph. SI units must be used. Scientific notation should be used when appropriate. 7. A conclusion section. This should include a discussion of the significance of the results, and suggested follow-up experiments. Be careful to be cautions in stating your conclusions, and support your conclusions with data. 8. An Experimental Procedure section. This describes your optimized procedures in a listed series of steps, and must be repeatable by a stranger. 9. A list of references should be the last section of your paper. Each reference must be cited in the paper. Web sites may be used, but scholarly works are considered preferable. These may include books or research articles, such as previous Journal articles. Consider using Google Scholar as a source for high-quality peer reviewed references. This is the hardest part. General websites such as Wikipedia may NOT be used. See the introduction to the journal for a good example. After the final rewrite, a printed copy will be turned in. Be sure to save your electronic version. This printed copy will be reviewed and returned with numerous improvements suggested. The revised version will then be graded and turned in and the final electronic copy only will be submitted to my dropbox. We will then use this to create the 2009 version (volume 3) of the Guilford Journal of Chemistry. Report due: ______________ Revised report and electronic copy due: _____________
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Please be sure to include all 9 items- it will be graded based on each item. Some ground rules and reminders: -As for all labs, safety is imperative. All experiments must be approved by me, and must be performed safely. Use a large tray to contain spills. Wear goggles. Do not perform experiments at home. You must supply your own soda and Mentos. Please bring some extra to help those who may need more.
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Names:
Period: Mentos Lab Report Form
Periods 1, 5,6: Hand In This Typed Completed Form by Thursday, September 18; save your file Period 2,3: Submit your Journal Article to my drop box by Friday, September 19. You may use this form to help you get started. Please divide the work between you and your lab partner to complete the following sections. You will be graded on the content in each area. 1. Title: One sentence that states what you discovered An excellent title quantitatively states a significant new discovery. Title: 3. A one paragraph summary of your experiment and results. Insert a nice picture of your experiment or the mentos eruption in general here. Add additional pictures wherever you want.
2. Your names By
3. Summary. A paragraph that briefly describes your discovery or invention. Be as bold as you can while still being able to fully defend the significance of your work. An excellent summary clearly states what you did and quantitatively discovered in a few sentences, comparing it to previous research. Summary:
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3. An introduction that summarizes what is known in your discovery area, with endnoted references. See the Guilford Journal of Chemistry, especially the introduction, for examples of useful references. The references go at the end of your report. An excellent introduction discusses relevant previous research in detail, citing at least 5 previous studies, and then connects it to the current study. Introduction
4. An experimental section that provides a listed procedure for your experiment. If your experiment is design-based, (for example the design of a remote control system) each iteration can be described here. An excellent experimental procedure should be written so that anyone could repeat it. Experimental 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. (add additional numbers if necessary)
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5. A results section. Describe your results. This must include a graph. Periods 1,5,6: this may be handwritten. Periods 2,3: this must be computer generated. SI units must be used. Scientific notation should be used when appropriate. An excellent results section quantitatively (use numbers and percents) states the results using proper units, points out data that doesn’t fit and explains it, and compares results to previous published studies.
Results
6. A conclusion section. This includes a discussion of the significance of the results, and suggested follow-up experiments. Be careful to be cautions in stating your conclusions, and support your conclusions with data. 7
An excellent conclusions data analyzes all data including previous studies and states a brief significant quantitative conclusion. It should also hypothesize why the results are what they are. It should finish by suggesting what might be done next to further the state of the art in this area. Conclusions
7. A list of references should be the last section of your paper. Each reference must be cited in the paper. If you use a website it must be specific and discussed in the footnote- see The Guilford Journal of Chemistry for examples. These may include books or research articles, such as those in previous GJC articles. Consider using Google Scholar as a source for high-quality peer reviewed references. An excellent reference section should include at least ten relevant peer-reviewed references that are properly cited throughout the text. Websites should be briefly discussed to explain their significance. These should be cited in the text with superscripts for example like this. They should be then listed at the end of the report- these are your endnotes. Previous Guilford Journal of Chemistry references or other scientific journal articles are excellent references. Website references are generally unreliable because they are not peer reviewed, and use no experiments to support their explanations- this is no better than simply making something up. References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. (add additional references if necessary)
Conceptual chemistry classes: Hand in a hard copy of this form. Level 1 classes: Use this form to generate a Guilford Journal of Chemistry research article and place the finished copy only in my dropbox. 8
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Topic
Mentos Lab Report Scoring Rubric Read this to make sure you get a nice high score. Your Explanation Value Score
1. Title (10 points) Is present States what you discovered 2. Summary (10 points) Is present Summarizes the results Uses numbers or percents to get quantitative results 3. Introduction (10 points) Is Present Includes relevant references Explains the mentos eruption using only conclusions supported by verifiable experiments Is related to the experiment 4. Experimental Section (10 points) Is present Is repeatable by a stranger 5. Results (10 points) Are present with a graph Are described using numbers Are significant- you discovered something Do not contain suspect data 6. Conclusion Is present Discusses the significance of the results Is cautious: does not draw conclusions that are unsupported by the data Tries to explain the reasons for the results Suggests relevant follow-up experiments Total
5 5 5 5 3 2
2 3 3
2 5 5 3 2 4 1 3 3 2
1 1 60
1. Title does not state what was discovered 2. Summary only provides qualitative results (use numbers, percents, or factors like 3x) 10
3. Introduction accepts eruption explanations that have no experimental support. Be cautious. Note that most experiments that are performed by scientists who have not researched the topic first repeat known results, and so are a ). 4. Experimental procedure not repeatable (usually because numbers not used- what is the size of the bottle, the hole at the top, etc.) 5. Results not quantified 6. Results have suspect data 7. Conclusions make no attempt to explain results 8. Conclusions do not suggest meaningful follow up experiments 9. References from unreliable sources 10. References not cited in text 11. Fewer than 5 references provided.
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Names______________________________ Period______________ Mentosapprovalform Application to Perform a Mentos Experiment All groups should fill out this application form and submit it to their instructor for approval To be approved, all experiments must 1. result in a significant new discovery concerning the Mentos Eruption. 2. result in quantitative and repeatable results 3. be fun to watch 4. be guaranteed safe to perform 1. Briefly describe your experiment:
2. What will you discover that is new from this experiment?
3. How will you be able to quantify your results?
4. How will you demonstrate that your results are reliable and repeatable?
5. What controls (positive or negative) will you include in this experiment?
6. What will the viewers enjoy the most about this experiment when you perform it?
7. What are the safety issues and how will you address them?
approved
rejected
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17
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Name________________________Period______________Date_________
WS2.1
Worksheet 1: SI Units and Unit Prefixes Directions: Please answer the following questions to the best of your ability. Since you will be tested on this material soon, try to answer the questions without referring to your notes unless necessary. 1. Speed is often expressed in miles per hour. However, using SI units, speed (velocity) is expressed in ____________ per ________. 2. Volume is often expressed in ounces, however in SI units volume is expressed in _____________. 3. Fill in the chart below, using the above examples as a guide. Unit of measurement We usually use Length Mass Temperature density
But SI units require
4. I have a 40 gigabyte hard drive. How many bytes is that? 5. Terabyte hard drives are available…how many bytes of data do they hold? 6. Try to fill in the following table, only referring to your notes if necessary: Prefix Symbol Factor Scientific notation Giga mega 1,000 centi 10-3 micro n
example
Microgram
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WS2.2 Name____________________________Period__________________Date________________ Density and Temperature Worksheet Please note: -you must show your work for credit -you must include the units in your answer for credit Rearrange your formulas here: If d = m/v, then m = ______________ and v = _____________ Example. What is the density of a sample that has a volume of 12 mL and a mass of 19 grams?
D = m/v = 19 g/12 mL = 1 . 6 g/mL (level 1 students: note 2 significant figures)
1. What is the volume of a sample that has a mass of 21 g and a density of 4 g/mL?
2. A liquid with a mass of 14 g is placed in a 50 mL graduated cylinder. The water rises from 20 to 41 mL. What is the density of the liquid?
3. A solid material that is insoluble in water has a volume of 35 mL and a mass of 39 grams at room temperature. Will it float in water? (The density of pure water at room temperature is 1.0 g/mL)
4. Aluminum has a density of 2.7 grams per milliliter. What is the mass of a sample of aluminum with a volume of 150 mL?
5. The temperature in degrees Celsius is 273.15 degrees lower than Kelvin: K = 273.15 + C. Convert the following common Celsius temperatures to Kelvin: Room temperature: 24 oC Freezing point of water: 0 oC Boiling point of water: 100 oC Absolute zero: -273.15 oC: 6. Ethanol has a melting point of 150 K and a boiling point of 351 K. Convert these to degrees Celsius.
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Name: _______________________________ Period___________ Date_______
WS2.3
Scientific Notation (Level 1 only) Please convert the following to scientific notation. Examples.
34,000 Red Sox fans; 0.0043 milliliters Solution: draw a line to make the number between 1 and ten, and adjust by powers of ten. 3
l 4,000 Red Sox Fans = 3.4 x 10
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Red Sox Fans
0.004 l 3 milliliters = 4.3 x 10-3 milliliters
1. 0.000058 inches 2. 5,798 grains of sand 3. 854,231 Obama voters 4. 0.936421 seconds 5. 1,200,000 miles 6. 0.285438563 kilograms 7. 4.000000092 grams 8. 26 students Please convert the following to standard notation.
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Name: _______________________________ Period_________________
WS2.4
Unit Conversion Worksheet I This worksheet is designed to show how to convert units, and provides some assistance. We will be converting units throughout the year, so it is essential that you learn how to set up your equations and properly cancel units. Note that all unit conversions 1. Begin with what you are given (in this case 21 days) Solution: 21 days x 1 week = 3 weeks 2. Multiply by conversion factors to convert units 7 days (in this case 1 week = 7 days) -where the unit being cancelled is divided by itself so it equals 1 (days in the example above) 3. Units are cancelled to make sure everything is set up properly.
Example: How many weeks are in 21 days?
Instructions: Please fill in the blanks and answer each question using the same type of setup shown above. No credit will be given unless 1. Units are included in the setup and answer (weeks, days, etc) 2. Units are cancelled properly (days cancel in the above equation) 1. How many hours are in 4.5 days? 4.5 days x --- hours = ___ hours day 2. How many weeks are there in 31 days?
31 days
x
____ = 4.43 weeks ____
3. How many weeks are there in 42 days?
42 days
x
____ ____
= ___weeks
4. There are 2.54 centimeters in an inch. How many centimeters are in six inches?
6 inches __________ x = 15.24 centimeters 1 inch 5. How many weeks are there in 365 days? Please show all your work and cancel units.
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6. How many centimeters are in 9 inches? Please show all your work and cancel units.
OK, now a bit harder. Example: How many inches are there in a meter? 2.54 cm = 1 inch; 100 cm = 1 meter Solution: 1 meter x 100 cm x 1 inch = 39.37 inches 1 meter 2.54 cm 7. How many inches are there in 3.2 meters? Solution: 3.2 meters x ________ x ________ = ___ inches 8. How many meters are there in 650 inches? Solution: 650 inches x ________ x _________ = _____ meters 9. How many meters are there in 7000 inches? Solution: Finally, if you can do these you have mastered unit conversion. Example: If I am moving at 3 centimeters per second, what is my speed in inches per minute? Solution: centimeters per second can be written as centimeters Second And inches per foot can be written as inches minute 3 centimeters x 1 inch x 60 seconds = 70.9 inches Second 2.54 centimeters 1 minute minute 10. If I am moving at 25 centimeters per second, what is my speed in inches per minute? Solution: ____________ x __________ x ___________ = ___ inches Minute 11. If I am moving at 65 miles an hour and the speed limit is 100 feet per second, am I speeding? (5280 feet = 1 mile; 60 seconds = 1 minute; 60 minutes = 1 hour) Solution: Solution: 65 miles x ________ x _________ x ___________ = feet Hour second Therefore I am/am not speeding (circle one).
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12. Solve the following math problem by cancelling units. Be sure to include your units at the end 9 centimeters 2 seconds
x
1 inch 2.54 centimeters
x 60 seconds = 1 minute
_______
And by the way, 9 meters every 2 seconds is the same as ___ meters per second 13. Here’s a different one. Based on the math answer below, write the question that was asked. Example
Answer: 70 days x 1 week = 10 weeks 7 days
Question: How many weeks are there in 70 days?
Answer: 25.4 centimeters x 1 inch x 1 hour = hour 2.54 centimeters 3600 seconds Question:____________________________________________
.0028 inches second
14. What units would result from the following question? Example
centimeters day Answer: inches per hour
centimeters hour
x
x
inch centimeters
inches centimeters
x
day = __________ hour
x hour x seconds = __________ seconds millisecond
Answer: 15. The boxed example above converted from centimeters per day to inches per hour. Show how to convert from 1 mile per hour to meters per second (1609 meters = 1 mile; 60 seconds = 1 minute; 60 minutes = 1 hour) Show your work below:
Answer: 1 mile per hour is the same velocity as _____ meters per second. 26
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Name_________________________ Period_____________
ws 2.5
Unit Conversion Worksheet Two Note: this worksheet is all about showing your work. For each question show your work and cancel your units. Once we begin working with unfamiliar units like micrograms, you’ll be glad you learned how to set things up. Example: How many eggs are there in 5.25 dozen eggs? Answer:1. Start with what you are given. 2. Write the final units. 3. Multiply by conversion factors to get your answer. 5.25 dozen eggs x
12 egg = 1 dozen eggs
63 eggs
1. How many eggs are in 62.25 dozen eggs?
2. How many shoes are in 2048 pair of shoes? (Remember, it’s all about setting it up. No credit will be given to those who just put down the answer.)
3. There are 2.54 centimeters in an inch. How many inches are there in 342,342 centimeters? (Should you divide or multiply? If you set it up correctly it will show you what to do.)
4. There are roughly 1.6 kilometers in a mile. If I hike 100 kilometers, how many miles have I hiked?
5. If I travel at 32 kilometers per hour (32 km/hr), what is my speed in miles per hour?
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Name_____________________________ Period_______________
WS2.6
L1 only Worksheet : Scientific Notation (L1 only)/Significant Figures (L1 only)/Percent Error The first question in most sections has been answered for you ď Š 1. Convert each of the following into scientific notation. 727
______7.27 x 102________________
172000
_________________________________
0.000984
_________________________________
200.0 x 102
_________________________________
0.014 x 102
_________________________________
2,560,000,000,000,000,000,000,000,000,000,000 ______________________ (use 4 sig. fig.) 2. Convert each into decimal form. Note that some use improper scientific notation. 1.56 x 104 ______15,600_____________________ 3.6 x 10-2 _________________________________ 736.9 x 105 _________________________________ 0.0059 x 105 _________________________________ 0.00059 x 10-1 _________________________________
3. Calculate the following. Give the answer in correct scientific notation. a) 2.34 x 1065 + 9.2 x 1066
b) 313.0 - 1.2 x 103
4. Calculate the following. Give the answer in correct scientific notation. a) 8.95 x 1076/ 1.25 x 1056
b) (4.5 x 1029)(2.45 x 10100)
5. Give the number of significant figures in each of the following. 29
a) 1.05 g ___3__ b) 0.0003040 mm ______ c) 29000 + 10 ft ______ d) 0.90 x 1045 L ______ e) the number of eggs (12) that make up a dozen
______
6. Determine the answer for each of the following. Be sure to use the correct number of significant figures. a) 17.34 4.900 + 23.1
b) 9.80 - 4.762
c) 3.9 x 6.05 x 420 =
d) 14.1 / 5 =
7. Round each of the following to 3 significant figures. 77.0653 ___77.1___
6,300,178.2 ______________
8. Find the percent error. Example: I am measure to be 180.0 cm tall, but my real height is 195.07.692 cm. This measurement is off by 15/195 x 100 = 7.692% a. A police officer clocked me doing 78 miles per hour, but I am certain the correct speed was 65 miles per hour. He was off by ___ percent.
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Name_________________ Period_______
WS2.8
Cars of the Future Unit Conversion Worksheet Many people believe that hydrogen powered vehicles will eventually replace gasoline powered vehicles in the near future. Perhaps the most compelling point is that the combustion of hydrogen creates (in theory) only one product: water. General Motors, the world’s second largest auto maker, is investing heavily in this area. A big question is this: Where’s the hydrogen? Other people believe electric cars will replace today’s gasoline powered vehicles. These vehicles have no emissions at all for the vehicle itself; the energy is produced at the power plant and the car is filled up by transferring the electrical energy to the vehicle over power lines, either at home or at a fuel station. Are they better for the environment? Are the vehicles cheaper to operate?...Is electricity cheaper than gasoline? Recently, hybrid gas/electric vehicles became available and their numbers are increasing. Perhaps you’ve been in one. And the race is on to bring to market one of the most exciting options- a plug-in hybrid electric vehicle. These vehicles can be charged at home like your cell phone, and these cars may not use any gasoline at all for trips under 40 miles. If recharging is cheaper than a fill-up at the gas station, and the batteries work well, the day may come when most vehicles use this system. In 2007 GM announced plans to develop a special type of gas-electric hybrid. As opposed to a conventional gas-electric hybrid vehicle like the 2007 Toyota Prius, this series-hybrid vehicle is propelled only by an electric motor; the supplemental gas motor is used only to recharge the battery. Below are some questions based on real data for these types of vehicles. Use your unit conversion skills to find out the pros and cons of each type of vehicle. The first question is solved for you. 1. A Mercedes test vehicle could hold 1.8 kg of hydrogen and had a fuel economy of 45 miles per kg. How far could it go on a tank of “gas” in miles? In kilometers? (1.61 kilometers = 1 mile)
Solution: 45 miles/kg x 1.8 kg = 81 miles 81 miles x 1.61 kilometers/mile = 1 30 kilometers
2. My Toyota has a 12 gallon tank and gets 30 miles per gallon. How far can it go on a full tank of gas?
3. How many miles further can my Toyota go, compared to the Mercedes?
4. Honda has H2-powered test vehicle with the same fuel economy as the Mercedes, but with a 4 kg tank. How far can it go on a full tank? Can it go as far as my Toyota?
5. Hydrogen costs 5 dollars per kilogram. How much does it cost to fill up the Mercedes and the Honda?
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6. Gasoline currently costs $2.25 per gallon. Use this data and that from the questions above to find out which car costs the least for a fillup- the Mercedes, the Toyota, or the Honda?
7. Right now hydrogen-powered vehicles operate at 35% efficiency. The manufacturers hope to boost that up to 70% in three years. What would the driving ranges of the Mercedes and Honda be if that happens?
8. The top speed of the Mercedes is 87 miles per hour. For how many hours could one drive the Mercedes with the petal to the metal?
9. Each Mercedes right now costs $500,000 and they have made 19 so far. Based on that, how much money has Mercedes sunk into their project so far? Level One Only: Express your answer using scientific notation.
10. Ok, here’s the big question. We’ve seen that the Mercedes gets 35 miles per kilogram of fuel. How does that compare to my Toyota, which gets 30 miles per gallon? (Helpful conversions: 1 gallon = 4.2 liters; 1 liter of gasoline has a mass of 0.7 kilograms).
11. OK, here is my favorite question. I’ve heard that the plug-in hybrids are cheaper to operate, since electricity is cheaper than gas. Being a skeptical scientist, I hunted around for data to support this. I found all kinds of bizarre and useless data, but here is the key data that makes for valid comparisons. Our gas powered car gets 30 miles per gallon, and gas currently costs $3.20 per gallon. A Toyota prius consumes 0.253 kilowatt-hours (kwh) per mile, and the electricity costs 10 cents per kwh. Calculate the costs per mile for each vehicle. How do they compare?
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Name___________________________________ Period___________
howtoaceit1&2
How to Ace your First Chemistry test Test 1 Units 1 and 2: Intro to Chem/Data Analysis I’m sure you would all like to ace your first chemistry exam. Here’s how. 1. Test yourself on the topics below. 2. Review the notes, worksheets, quizzes, and the Mentos Eruption Experimiment and lab reports. 3. Write down what you don’t know yet. If you don’t know something, ask a friend or ask me. 4. For this exam pay particular attention to unit conversions and significant figures- they are the toughest topics to master. 5. Review the lessons using Dr. B.’s website: http://www.chemadventure.com Topics: 1. Data Analysis SI units: a. time,
2. Prefixes:
e. amount,
b. length,
f. density,
c. mass,
g. volume
d. temperature,
h. luminous intensity
a. giga, b. mega, c. kilo, d. deci, e. milli, f. micro, g. nano,
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h. pico i. List the units from pico to giga: 3. Density equation and problems: d = m/v
Example: What is the density of a substance with a mass of 2.4 grams and a volume of 3.2 mL?v True or false: The question above is a unit conversion problem. True or false: d = mv? True or false: v = md?
4. Kelvin to Celsius temperature equation and problems K = oC + 273
Example: 298 K = _____oC.
5. Scientific Notation (L1 only)
Example : Convert 6.2 x 10-4 to a regular number :__________
6. Percent Error a. What is the formula for percent error?
Example: If I have a mass of 142 pounds, but my balance says my mass is 152 pounds (ouch!), what is the percent error of that balance? 7. Unit conversion Show your work below :
a. 12 kg = _____g b. 3 hours = ________ seconds
c. 36 dozen eggs = __________ eggs
d. 25 miles = ____________ meters
e. 36 miles/hour = ________meters/second f. 3.2 x 10-23 picometers/year = _________miles/hour 8. Significant Figures (L1 only)
Example : 3.21 has ___ significant figures 34
Example : 3.201 has ___ significant figures Example : 0.321 has ___ significant figures Example : 3.210 has ___ significant figures Example : 3.21 x 2.4 has ___ significant figures Example : 3.21 + 4.234136 has ___ significant figures
Give the answers using the correct number of significant figures (L1 only) a. 3 + 2 = ________ b. 3.0 + 5.000 =________ c. 14.21 x 32.4809 =________ d. 15.5112123 + 4 =________ e. What is the volume of a piece of metal that has a mass of 3.2 grams and a density of 2.703 grams per cubic centimeter ? ________
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