Hour Exam

1
Hour Exam 2

• September 30, 2005

2

• Using the decision trees (attached), show a
  series of steps where CH3OH would be converted to
  CO2 (Partial Credit will be given).
• CH3OH OH ? CH3O H2O ? CH3O O2 ? O2H
  CH2O
• CH2O (formaldehyde) OH ? H2O CHO (could
  occur by UV radiation also)
• CHO O2 ? CO O2H ? CO OH ? HO-C-O
• HO-C-O O2 ? CO2 O2H

3
Based on the bonding strengths of the loose
oxygen, identify those reactions that would occur
in the troposphere.

• NO O2 ? NO2 O NO
• Cl O2 ? ClO O NO
• NO O3 ? NO2 O2 YES
• O3 O ? 2 O2 YES
• ClO NO ? NO2 O2 NO
  (products have no chlorine)

4

• 10 pts. The figure on the right shows the light
  emitted from the earths surface and the light
  leaving the upper atmosphere as a function of
  wavelength. Explain why the two curves are not
  the same. Identify on the graph the regions of
  most concern when one is assessing the potential
  impact of a new gas to be released into the
  troposphere.
• The curves are not the same because of absorption
  of IR by greenhouse gases. The region of
  concern would be between 10 15 mm where there
  is nothing currently absorbing.

5

• The figure on the right shows a system that has
  reached a steady-state. Using CO2 as the model,
  how would you expect the graph to change if we
  reduce the amount of gasoline we burn, and (b)
  explain how the graph would change if the oceans
  get warmer, reducing the amount of CO2 absorbed.
• If we reduced the amount of gasoline we burn, I
  would expect the steady-state level to decrease,
  and on the other hand, I would expect the
  steady-state level to increase if we reduce the
  sink for the carbon dioxide.

6

• The figure on the left shows a relative
  comparison of the contributions of greenhouse
  gases to global warming.
• How do you explain the relatively large
  contributions of CFCs and N2O when their
  concentrations are 1000 times less than CH4 and
  CO2?
• How do you explain the negative contribution
  (cooling effect) of aerosols?
• The relative magnitude is a function of
  efficiency, where they absorb, and the residence
  time. These factors would influence the
  contribution.
• Aerosols reflect the incident light resulting in
  a cooling effect.

7

• List four documented observations that support
  the position that the world is getting warmer.
• Documented global temperature rise since 1880
• (0.3 to 0.6 Celcius over past century)
• Winters are getting shorter
• Accelerated melting of Alpine glaciers.
• A sea-level rise of 10 to 25 cm. over past 100
  years.
• Coral bleaching caused by abnormally high
  sea-surface temperatures.
• The Earths ice cover is shrinking fast
• Mosquito-borne diseases have reached higher
  altitudes

8

• At the G8 Summit meeting this summer, the leaders
  discussed global warming and the future
  development of Africa. They issued four
  statements and/or goals with regard to global
  warming. List two of them.
• First, Participants agreed that Climate Change
  was indeed a problem, with human activity
  contributing to it.
• Second, that the participating members had to
  tackle it with urgency.
• Third, that in order to do that, nations have to
  slow down, stop and in time reverse greenhouse
  gas emissions.
• Fourth, the participating nations put in place a
  new dialogue involving the G8, the emerging
  economies and the key international institutions
  to create a pathway to a post Kyoto agreement, so
  that when Kyoto expires after 2012, the world can
  act with unity.