Practice Test #1

Practice Test #1
Examples of questions used in the
past on Stratospheric chemistry
and Urban Air
Convert 0.0010 grams/ liter to ppm
0.0010 grams/1000 grams = 1.0x10-6 grams solute/gram
= 1 ppm
Not all XO molecules such as NO2 survive long enough to react
with oxygen atoms; some are photochemically decomposed to X
and atomic oxygen, when then reacts with O2 to reform ozone.
Write out the three step (including one for ozone destruction)
for this process and add them together to deduce the net
reaction. Does this sequence destroy ozone overall or not?
XO –l  X + O
O + O2  O3
O3 + X  XO + O2
Adding these up gives no change in ozone.
Acid rain continues to be a problem in this country. (a) List two
sources of acid rain, (b) two effects of acid rain, and (c) two ways to
reduce acid rain.
(a) Any source such as sulfur from utility plants, automobiles, industrial
processes producing SO2 and/or NO2 would be accepted.
(b) Acid rain effects vegetation, health, natural waters, and structures
(c ) acid rain can be reduced by reducing amount of SO2 formed,
dilution of SO2, scrubbers, conversion to other products.
In the figure on theright, it is
determined that the
concentration of ozone, O3, is at
point “A”, 240 ppb. How would
you reduce the concentration of
ozone to 80 ppb. Be specific,
and include actions you would
initiate and how you would
insure their success.
Must reduce either the NOx or
VOC until you are on the line
corresponding to 80 ppb. To
ensure success will require
Multiple Choices
1. (5 pts) When one considers acid rain
(a) the gas of principal concern is H2S
(b) the region influenced must have a high buffering capacity
(c )the concentration of the oxide, particularly NOx and SO2, are critical factors
in the ultimate acidity
(d) the primary impact is bleaching of coral reefs.
(c ) these are the compounds that cause acid rain.
(5 pts.) Acid rain
(a) does not occur where temperatures are below 18oC
(b) causes limestone structures to degrade over time
(c )causes an increase in global warming
(d) is not a problem in North Carolina
(b) Causes limestone structures to degrade over time.
(9. (5 pts) 10 mg/liter is equivalent to:
(a) 10 ppm (b) 1 ppm (c) 0.1 ppm (d) 0.01 ppm
(e) 10 ppb
(a) 10 ppm
. Which of the following is a radical?
a. CCl3
b. CCl4
(a) CCl3
c. N2O
d. CO
5 pts) The concern in southeastern North Carolina regarding nitrogen deposition
from hog waste is:
changing the pH of rivers
nutrient loading
regional global warming
acid rain
(b) nutrient loading
(5 pts.) In photochemical smog
sunlight is required to break the ozone and NO2 bonds
the hydroxyl radical is not a requirement
ozone is not a requirement since oxygen atoms will cleave from NO2
the reactions occur more rapidly in colder environments.
(a) Sunlight is required to break the ozone and NO2 bonds
(15 pts) The figure on the right shows
the concentrations of ClONO2 and HCl in
the gasous phase over the Antarctic for a
twelve month period. Explain how these
concentration variances explain the
development and recovery of the ozone
hole over the Antarctic.
Emphasize here the HNO33H2O crystals,
ClONO2 and HCl freezing out, HOCl and
Cl2 evaporating, breaking down to give Cl
radicals as the sun appears, causing
ozone destruction. No new ozone until
earth turns and HNO33H2O crystals
melting and trapping OCl with NO2, plus
new ozone formed.
The figure on the right shows
the concentrations of the
important pollutants that
cause photochemical smog.
(a) (5 pts) Identify the
pollutants labeled:
A = VOCs
C= Ozone
D= [NO]
E= [NO2]