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Reducing Carbon Dioxide in the Atmosphere

September 2001
Reducing CO2 Menu
Introduction
Assessment
Achievement Task

Scenario

You are a reporter for the Environmental News Network (ENN). You are investigating ways of reducing carbon dioxide emissions and Greenhouse Gases. Your task is to first of all research sources of Greenhouse Gases (GHGs) and then plausible methods of reducing these emissions.

You will also perform an experiment related to one method of reducing carbon dioxide levels. Some researchers have proposed that carbon dioxide should be pumped into the deep waters of the Norwegian Sea. By investigating the solubility of carbon dioxide at different temperatures, you will be able to make an informed decision about using this method to lower atmospheric carbon dioxide.

You are required to write an article for ENN that could be published on their web site. This article should include:

  1. a summary of the all GHGS and their sources, with special consideration given to the role automobiles in GHG production
  2. a description of methods currently in place or being suggested as ways of reducing emissions (ex. pumping CO2 into the ocean, testing automobile emissions etc.)
  3. a summary and the results of an experiment on carbon dioxide solubility
  4. a discussion regarding the practicality of the different methods used to reduce GHGs and your recommendations of the best method

Part A: Research

1. Use a variety of resources to research all GHGS and their sources, with special consideration given to the role automobiles in GHG production.

2. Use a variety of resources to describe the methods currently in place or being suggested as ways of reducing emissions. A description of the technologies involved should also be included.

3. Summarize your results in an appropriate format.

Part B: Testing and Inquiry

[Lab] THE SOLUBILITIES OF CARBON DIOXIDE IN WATER AT VARIOUS TEMPERATURES

PURPOSE:

Students will measure the amount of carbon dioxide in samples of Seltzer or Soda water in order to determine a trend in the solubility of the carbon dioxide as a function of temperature. They will relate their results to suggested methods of GHG reduction such as dumping CO2 in oceans.

Their measurements could also be used to determine the volume of CO2 in Seltzer water or as the basis for a discussion about the concept of buoyancy and its importance when massing objects whose masses are small compared to their volumes.

INTRODUCTION:

Carbonated beverages are bottled under a carbon dioxide pressure slightly greater than standard pressure. As a result, when the bottles are opened to the air, the partial pressure of CO2 above the solution is decreased and CO2 bubbles out of the solution. The bottles should be cold when opened because CO2 is most soluble at low temperatures and by opening the bottles prior to doing the experiment, the dissolved CO2 is allowed to reach equilibrium with the lower pressure of CO2 in the air. When carbon dioxide dissolves in water, it forms an acidic solution, as shown by the following equation, which can be neutralized by the addition of base.

CO2 (aq) + H2O (l)  H+(aq) + HCO3-(aq)

The results obtained by this procedure are will only indicate a trend in the solubility of the carbon dioxide as a function of temperature and will not agree with literature values for the solubility of carbon dioxide which are usually measured at higher partial pressures of the gas.

MATERIALS

Soda water

 thermometers

2.0 M NaOH solution

 100-mL graduated cylinders

phenolphthalein solution

 200-mL Erlenmeyer flasks

1-L beakers

 eye dropper

burettes

ice bath and warm water bath - large enough to hold a 1-L beaker

HAZARDS

The NaOH solution is caustic; avoid contact with skin. Goggles must be worn throughout the experiment.

PROCEDURE

Sample preparation by teacher:

Prior to lab session, prepare samples by placing unopened bottles of Soda or Seltzer water in an ice-water bath until samples are at temperature of bath. About 0.5 hour before students are to begin the experiment, open the necessary number of bottles of Seltzer water and mix their contents. Divide this mixture among three 1-L beakers. Place one beaker in the ice-water bath, allow one beaker of Seltzer to stand at room temperature and place the other in a warm water bath.

Experimental procedure:

  1. Measure out 50 mL of Seltzer water and transfer it to an Erlenmeyer flask. Add 3 drops phenolphthalein solution and swirl gently for one minute to remove any remaining mechanically trapped carbon dioxide.

  2. Use correct techniques to fill a burette with 2.0 M NaOH solution. Titrate with prepared Seltzer water until the pink phenolphthalein color persists for 30 seconds. Record the volume of NaOH solution used. Repeat titration two more times, if time permits.

  3. Repeat steps 1 and 2 using samples at different temperatures.

  4. When finished, rinse burette with dilute acid before cleaning. All samples may be flushed down the drain.

Analysis

  1. Present all observations in a table format.
  2. Plot a graph of volume of NaOH solution required for neutralization vs. temperature
  3. Calculate the volume of carbon dioxide in your Seltzer water taking into account experimental conditions

Conclusion and Evaluation

Draw a conclusion about how the solubility of carbon dioxide varies with temperature and describe any sources of error..

Using your experimental and research results, evaluate the plausibility and practicality of dumping CO2 into the ocean as a method of reducing atmospheric CO2. Also consider other factors that would effect its solubility besides temperature.

Note: This activity is based on a lab submitted by Eva Lou Apel, Michael Bannon, Joseph Baron, John Brodemus, and Elna Clevenger to the 1986 Woodrow Wilson Leadership Program in Chemistry (lpt@www.woodrow.org )

Part C: Analyze and Reflect

In the research part of this activity, you investigated various GHGs, their sources and methods of reduction. Use your research and the results from your experiment to write a report analyzing what is currently being done to reduce GHGs and make recommendations as to what should be done by governments, industries, and individuals to reduce GHGs.

Part D: Communicate

Prepare an article summarizing your findings for the ENN web site. Your article should include:

  1. an introduction
  2. a summary recorded in an appropriate format of: all GHGS and their sources, including automobiles; the methods currently in place or being suggested as ways of reducing emissions; and a description of the technologies involved.
  3. a summary of your experimental procedure, results and analysis
  4. an analysis of what is currently being done to reduce GHGs and recommendations as to what should be done by governments, industries, and individuals to reduce GHGs.
  5. graphics or photos to complement the text
  6. a conclusion that considers the future outlook for the success of the Kyoto Protocol and reduction of GHGs
  7. all references used listed in APA style

 

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Last Modified 11/21/2001