UCSD ID Number______________________
Chemical Families and Cycles (60 pts: 10, 10, 10, 10, 10, 10)
What is the name for the chemical family that includes precursors and products that can be easily converted to
or from NO, NO
? Why is it important in atmospheric chemistry?
Name the main atmospheric reservoirs of sulfur. For each reservoir, name the chemical compound, write its
chemical formula, and identify the oxidation state of sulfur.
What is the Sulfur cycle? Describe its components, interfaces, and processes.
What is the most important manmade type of source of NO
Which reservoir is responsible for the removal of most of the reactive nitrogen? What is the process (or
processes) responsible for this removal?
is the chemical family that includes precursors and products that can be easily
converted to or from NO
, such as PAN, HONO. NOy is important because compounds in the
NOy family are stable enough to be transported to remote regions where they will thermally
decompose into NOx and create pollution.
b) The six atmospheric reservoirs of sulfur are SO
(sulfur dioxide, +4), SO
S (hydrogen sulfide, -2), COS (carbonyl sulfide, -2), DMS (dimethyl sulfide, -2), and CS
(carbon disulfide, -2).
c) The Sulfur cycle is the pathways by which and reservoirs through which compounds of
nitrogen are transferred among the atmosphere, the hydrosphere (including the oceans), the
biosphere (including plants), the cryosphere, and the geosphere (including soil). The primary
interfaces across which sulfur is transferred are the ocean-atmosphere and the biosphere-
atmosphere interfaces. The processes that control these transfers include combustion
emissions (fossil fuel and biomass, anthropogenic and natural) of SO
, volcanic emissions of
soil emissions of H
S and COS, and algae production of DMS and CS
wet/dry deposition of SO
to the ocean and land surfaces, as well as in situ
d) Fossil fuel burning.