B) excited oxygen molecules
C) ozone
D) ozone and atomic oxygen
E) atomic oxygen
6) The C Cl and C F bond dissociation energies in CF3Cl are 339 kJ/mol and 482 kJ/mol, respectively.
The maximum wavelengths of electromagnetic radiation required to rupture these bonds are
__________ and __________, respectively.
A) 45.0 nm, 307 nm
B) 742 nm, 654 nm
C) 482 nm, 248 nm
D) 353 nm, 248 nm
E) 979 nm, 953 nm
7) The C O bond dissociation energy in CO2 is 799 kJ/mol. The maximum wavelength of
electromagnetic radiation required to rupture this bond is __________.
A) 307 nm
B) 149 nm
C) 248 nm
D) 353 nm
E) 979 nm
8) The amount of atomic O relative to O2 __________.
A) is highest in the troposphere
B) is highest in the stratosphere
C) increases with altitude in the thermosphere
D) decreases with altitude in the thermosphere
E) is essentially independent of altitude in the thermosphere
14
9) In the equation below, M is most likely __________.
O + O2 + M → O3 + M*
A) Cl2
B) N2
C) Ne
D) CO2
E) H2O
10) Ozone is a(n) __________ of oxygen.
A) isomer
B) allotrope
C) isotope
D) resonance structure
E) atomic form
11) CFC stands for __________.
A) chlorinated freon compound
B) chlorofluorocarbon
C) carbonated fluorine compound
D) caustic fluorine carbohydrate
E) carbofluoro compound
12) Natural, unpolluted rainwater is typically acidic. What is the source of this natural acidity?
A) CO2
B) SO2
C) NO2
D) HCl
E) chlorofluorocarbons
13) What compound in limestone and marble is attacked by acid rain?
A) hydroxyapatite
B) calcium carbonate
C) gypsum
D) graphite
E) potassium hydroxide
14) CO2 from hydrocarbon combustion creates a major environmental problem that is described as
__________.
A) the greenhouse effect
B) photochemical smog
C) acid rain
D) stratospheric ozone depletion
E) all of the above
15) The majority of SO2 released annually in the United States results from __________.
A) combustion of oil
B) acid rain
C) combustion of coal
D) depletion of ozone by CFCs
E) all of the above
16) Radiation in the infrared portion of the spectrum is absorbed by __________ found in the
atmosphere.
A) N2
B) O2
C) CO2
D) Ar
E) He
17) Compounds found in fossil fuels that contain __________ are primarily responsible for acid rain.
A) sulfur
B) carbon
C) hydrogen
D) phosphorus
E) neon
18) Acid rain typically has a pH of about __________.
A) 7
B) 5
C) 4
D) 2
E) 1
19) Sulfur dioxide is not released into the atmosphere in any significant amount by __________.
A) burning of coal
B) bacterial action
C) internal combustion engines
D) volcanic eruption
E) Sulfur dioxide is produced in significant amount by all of these processes.
20) Ozone is a necessary, protective component of the __________, but is considered a pollutant in the
__________.
A) troposphere, upper atmosphere
B) troposphere, air
C) photochemical smog, air we breathe
D) upper atmosphere, troposphere
E) air we breathe
21) The brown color of photochemical smog over a city is mainly due to __________.
A) NO2
B) N2O4
C) CO
D) SO2
E) CO2
22) The concentration of which greenhouse gas has increased steadily over the last few decades?
A) H2O
B) CO
C) CO2
D) H2O2
E) O2
23) What is the percentage of freshwater on planet Earth?
A) 97%
B) 2.1%
C) 2.8%
D) 0.6%
E) 100%
24) In the world’s oceans, the average salinity is about __________ g/kg.
A) 0.03
B) 0.1
C) 35
D) 17
E) 3.5
25) The sterilizing action of chlorine in water is due to what substance?
A) Cl–
B) Cl2
C) HCl
D) HClO
E) H+
26) The “scale” caused by hard water is __________.
A) calcium ions
B) calcium carbonate
C) chloride ions
D) magnesium oxalate
E) magnesium ions
1) The concentration of water vapor in a sample of air that has a partial pressure of water of 0.91 torr
and a total pressure of air of 735 torr is __________ ppm.
A) 1.2 × 103
B) 1.2
C) 0.12
D) 8.1 × 10-4
E) 0.81
2) A sample of air from a home is found to contain 6.2 ppm of carbon monoxide. This means that if the
total pressure is 695 torr, then the partial pressure of CO is __________ torr.
A) 4.3 × 103
B) 4.3 × 10-3
C) 4.3
D) 8.9 × 103
E) 1.1 × 108
3) The concentration of ozone in a sample of air that has a partial pressure of O3 of 0.33 torr and a total
pressure of air of 735 torr is __________ ppm.
A) 4.5 × 102
B) 0.45
C) 0.045
D) 2.2 × 10-3
E) 2.2
4) The mole fraction of carbon dioxide in dry air near sea level is 0.000375, where the molar mass of
carbon dioxide is 44.010. The partial pressure of carbon dioxide when the total atmospheric pressure
(dry air) is 97.5 kPa is __________ kPa.
A) 2.63 × 105
B) 5.97 × 103
C) 0.0370
D) 1.63
E) 8.40 × 10-4
5) The concentration of carbon monoxide in a sample of air is 9.2 ppm. There are __________
molecules of CO in 1.00 L of this air at 755 torr and 23 °C.
A) 3.8 × 10-7
B) 2.2 × 1021
C) 2.9 × 1018
D) 1.7 × 1020
E) 2.3 × 1017
6) The mole fraction of helium in dry air near sea level is 0.00000524 where the molar mass of helium
is 4.003. The concentration of helium in the atmosphere is __________ ppm.
A) 1.91 × 1011
B) 5.24 × 10-4
C) 5240
D) 5.24
E) 5.24 × 10-12
7) The mole fraction of oxygen in dry air near sea level is 0.20948. The concentration of oxygen is
__________ molecules per liter, assuming an atmospheric pressure of 739 torr and a temperature of 29.5
°C.
A) 6.23
B) 0.00819
C) 4.93 × 1021
D) 3.75 × 1024
E) 5.07 × 1022
8) Components of Air Mole Fraction
Nitrogen 0.781
Oxygen 0.209
Argon 0.010
What is the partial pressure or oxygen (in torr) in the atmosphere when the atmospheric pressure is
765.0 torr?
A) 160.
B) 597
C) 611
D) 7.65
E) 760
9) Components of Air Mole Fraction
Nitrogen 0.781
Oxygen 0.209
Argon 0.010
What is the partial pressure or nitrogen (in torr) in the atmosphere when the atmospheric pressure is
765.0 torr?
A) 160.
B) 597
C) 611
D) 7.65
E) 760
10) Components of Air Mole Fraction
Nitrogen 0.781
Oxygen 0.209
Argon 0.010
What is the partial pressure or argon (in torr) in the atmosphere when the atmospheric pressure is 765.0
torr?
A) 160.
B) 597
C) 611
D) 7.65
E) 760
11) The dissociation energy of the C-Cl bond in CF3Cl is 339 kJ/mol. The maximum wavelength of
light that has enough energy per photon to dissociate the C-Cl bond is __________ nm.
A) 1130
B) 3.53 × 10-4
C) 3.53 × 10-7
D) 3.53 × 105
E) 353
12) The ionization energy of O2 is 1205 kJ/mol:
O2 + hv → O2+ + e–
The maximum wavelength of light capable of causing the ionization of O2 is __________ nm.
A) 4017
B) 9.94 × 10-5
C) 9.94 × 10-8
D) 99.4
E) 9.94 × 104
13) The concentration of Br– in a sample of seawater is 9.3 × 10-4 M. If a liter of seawater has a mass of
1.0 kg, the concentration of Br– is __________ ppm.
A) 0.074
B) 74
C) 0.93
D) 9.3
E) 0.0093
18.4 Short Answer Questions
1) The fourth most abundant component of dry air is __________.
2) A chemical bond rupture resulting from the absorption of a photon is called __________.
3) The concept that radiowave propagation was affected by the atmosphere of the earth was discovered
by __________.
4) In the equation below, what is the meaning of the asterisk?
O + O2 → O3*
5) Approximately 90% of the earth’s ozone is in the __________.
6) Show how a molecule of C2F2Cl2 can destroy two molecules of ozone, O3.
7) In addition to nitrogen oxides, __________ are a major contributor to the depletion of the ozone
layer.
8) Clean rainwater is acidic mainly due to the presence of __________.
9) The approximate pH of acid rain is __________.
10) The contribution of sulfur to acid rain is via the production of __________.
11) The primary chemical pollutants that create acid rain are __________ dioxide and __________
oxides.
12) Nitric oxide arises from auto emissions and reacts with oxygen to produce __________ which reacts
with sunlight to produce __________ atoms which react with oxygen to produce __________.
13) The salinity, density, and temperature of seawater varies with __________.
14) The three most concentrated ions in seawater are __________.
15) The average pH of the oceans is __________ and is maintained by the buffering capacity of
__________.
16) The average adult in the U.S. needs __________ liters of water per day for drinking.
17) The world’s largest desalinization plant is in __________ and uses the process of __________ to
produce drinking water.
18) The production of dead and decaying plant material is a process called __________.
19) In the purification of drinking water, the filtered water is made basic by adding ________, then
particles and bacteria are captured by adding __________.
18.5 True/False Questions
1) When dealing with gases, the volume fraction and the mole fraction are the same.
2) The bond energy of oxygen is higher than that of nitrogen.
3) The partial pressure of a component in a gas mixture is the product of its mole fraction and the total
mixture pressure.
4) Nitrogen oxides catalytically destroy ozone.
5) Ozone depletion from chlorofluorocarbons is chiefly due to the production of free chlorine.
6) Nitric oxide arises from internal combustion engines.
7) Sulfur compounds in the atmosphere are equally derived from natural sources
and from human activity.
8) The greenhouse effect of a methane molecule far exceeds the effect of a carbon dioxide molecule.
9) The principal component of smog is sulfur dioxide.
10) Most fresh water in the U.S. is used for agriculture.
11) Municipal water treatment consists of five steps ending with chlorination.
18.6 Essay Questions
1) Describe the process of reverse osmosis that is used to desalinate seawater.
2) How can the presence of biodegradable waste in a lake result in the death of fish in the lake?
3) List two of the three major sources of nitrogen and phosphorus in water.
4) Ozone is more efficient at killing bacteria in water yet chlorine is used more commonly for that
purpose in municipal water treatment. Why?