Today humans release about 5 billion tons of carbon to the atmosphere every year through the burning of fossil fuel and cement manufacture. Approximately another 1
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- Navigate this page:
- Background Information
- Problem
- Prelab Questions
- Particulate and CO 2 Emissions Hypothesis
- Particulate Collection
- Lab Observations / Errors Noted: Tailpipe Emissions Data Table
- Observations
- Conclusions
Lab modified from www.woodrow.org/teachers/esi/1998/p/humansources/sourceslab-student.htm by Perri Carr Background Information: Today humans release about 5.5 billion tons of carbon to the atmosphere every year through the burning of fossil fuel and cement manufacture. Approximately another 1.5 billion tons per year are released through land use changes such as deforestation. These releases result in an increase of atmospheric CO2 of about 1/2% per year. This increase is the most plausible explanation for the warming trend we have seen since the mid-19th century. Problem: Which automobiles produce the most pollution? Is the amount of pollution (large particulates) linked to the amount of CO2 produced? Materials: automobile, adult supervisor, watch, coffee filters, tape, permanent marker, safety goggles, metric ruler, CO2 sensor, Lab Pro or Xplorer GLX, 2 liter bottle and syringes, paper, heat resistant glove, large padded twist tie (17”) Prelab: Go to the “Fuel Economy” website https://www.fueleconomy.gov/feg/Find.do?action=sbsSelect. Compare your car side by side with another car of your choice. Step through the various tabs to compare the cars. Print out and attach your results. Answer the following questions in the blanks provided. Prelab Questions: 1. What factor seems to determine how much carbon dioxide is emitted in a year? 2. If you drove your car 200 miles in a week, compute the amount of CO2 produced in pounds using the following information: 1 mile = 1.609km, 1 gallon = 3.785 liters, 1 pound = 0.435kg Approximate miles per gallon of your vehicle. Approximately 20lbs (9 kg) of CO2 are produced per gallon of gasoline consumed. (show all calculations) Calculate the pounds of CO2 emitted in a week and a year (52 weeks of driving at 200 miles per week). Continue on next page if necessary. Particulate and CO2 Emissions Hypothesis: Before doing the experiment, make an educated guess about which vehicles being tested will have the highest carbon dioxide emissions. Write your hypothesis in this space. Procedures: Have one student start the car and run it for 30 seconds. Do not touch the accelerator or put the car in gear. Follow safety procedures of a gas mask & goggles. Remember, tail pipes can be hot. A heat resistant glove is recommended. CO2 Collection: Carbon dioxide can be measured directly with a CO2 sensor or collected in a 20 ml syringe and diluted before sampling with the CO2 sensor. Collect a sample of gas from the automobile exhaust. The students collecting the sample should wear safety goggles. Using the 20ml syringe, the sample should be taken directly in front of the tailpipe. Have students stand to the side of the tailpipe to collect the sample. D  irect Method: Place the CO2 sensor in the exhaust pipe opening. Open the chamber and insert the syringe tip to the bottom of the container. Measure the CO2 output in ppm until it stabilizes (+/- 10% ppm).
Dilution Method: Cut a circle on the side of a 2 L bottle to allow the CO2 sensor to be inserted into the bottle snugly. Plug the hole with a rubber stopper when not in use. Attach the gas pressure stopper to the bottle cap opening to enable gas injection. Inject the exhaust sample into the dilution chamber (the 2L bottle) which has the gas pressure sensor adaptor attached to the bottle opening. The 20 ml sample in a 2L bottle is a 1:100 dilution and enables a CO2 sensor that maxes out at 10,000 ppm to be used. Newer CO2 sensors that can go up to 50,000 ppm can be used directly without dilution. Follow instructions to measure the CO2 reading with the Vernier probe or Pasco probe. Record the data.  Gas pressure stopper & syringe
Turn the car off. Test the sample using the method described by your teacher. Particulate Collection: Place the coffee filter tightly over the mouth of the car's exhaust with a large padded twist tie. Start the engine of the car and run it for 3 minutes. Turn the car off. Small holes may need to be punched into the coffee filter before use to prevent the filter from popping off when the car is started. Remove the coffee filter and return to class. Label the filter with the name & year of the car. Observe the particulates. Do not handle it any more than necessary. Arrange coffee filters in order from dirtiest to cleanest based on student observation. Record in Tailpipe Emissions data table. Answer the following questions. Observations_/_Errors_Noted:___Tailpipe_Emissions_Data_Table'>Lab Observations / Errors Noted: Tailpipe Emissions Data Table
Observations: 1. Do the vehicles that emit the highest level of pollutants have anything in common? 2. Do the vehicles that emit the least level of pollutants have anything in common? 3. Which tested vehicle emitted the highest level of CO2? a. Does this car have a catalytic converter? Research online and describe the purpose of a catalytic converter.
1. Was your hypothesis supported by this experiment? Why or why not? 2. Describe how the U.S. A. could encourage people to drive less or use a more efficient means of transportation as a way to reduce photochemical smog and carbon dioxide emissions. 3. Review the main sources for carbon dioxide in the U.S. at http://www3.epa.gov/climatechange/ghgemissions/gases/co2.html. a. List the sources from highest to lowest. b. The CAFÉ (Corporate Average Fuel Economy) standards have recently been altered to become significantly more stringent in 2016. Read about these changes, which vehicles are affected and describe three ways this will US energy use and climate change. http://www.nhtsa.gov/fuel-economy. c. In August, President Obama announced the Clean Power Plan. Describe the main points and proposed benefits at this website: http://www2.epa.gov/cleanpowerplan/clean-power-plan-existing-power-plants. What is the timeline for implementation of this plan? Download 85.45 Kb. Share with your friends:
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