In the troposphere, temperature ________ with increasing altitude, while in the stratosphere, temperature ________ with increasing altitude.
A) increases, increases
B) decreases, decreases
C) increases, decreases
D) decreases, increases
E) decreases, remains constant

D

Which of the following is arranged correctly in order of increasing distance from Earth's surface?
A) mesosphere < troposphere < stratosphere < thermosphere
B) troposphere < mesosphere < stratosphere < thermosphere
C) troposphere < mesosphere < thermosphere < stratosphere
D) troposphere < stratosphere < mesosphere < thermosphere
E) mesosphere < troposphere < thermosphere < stratosphere

D

Which of the following is released by the combustion of fossil fuels?
A) N2
B) CO2
C) H2
D) O2
E) O3

B

As one gains altitude in the atmosphere, based on the ionization energies shown below, which sequence of mole fractions is the correct one?

Process, Ionization Energy (kJ/mol)
N2 + hν → N2+ + e-, 1495
O2 + hν → O2+ + e-, 1205
O + hν → O+ + e-, 1313
NO + hν → NO+ + e-, 890

A) N2 > N > NO > O2
B) N2 > O > O2 > NO
C) N2 > O2 > O > NO
D) NO > O2 > O > N2
E) All will be equal.

B

Why does the upper atmosphere contain only very little dissociated nitrogen?
A) Most of the nitrogen is in the troposphere and not in the upper atmosphere.
B) The dissociated nitrogen very rapidly diffuses out of the atmosphere and into space.
C) Nitrogen atoms are extremely reactive and so react with other substances immediately upon their formation.
D) The bond energy of nitrogen is very high and it does not absorb radiation very efficiently.
E) There is no N2 in the upper atmosphere.

D

Of the compounds below, the one that requires the shortest wavelength for photoionization is ________.
A) O
B) O2
C) NO
D) N2
E) They all require the same wavelength.

D

Photoionization processes (e.g., N2 + hν → N2+ + e-) remove UV of < 150 nm. Which photoreaction is the principal absorber of UV in the 150-200 nm range in the upper atmosphere?
A) N2 + hν → 2N
B) O2 + hν → 2O
C) O3 + hν → O2 + O
D) N2 + O2 + hν → 2NO
E) NO + O2 + hν → NO3

B

The majority of ozone that protects against the high energy radiation of the sun is found in the ________.
A) thermosphere
B) mesosphere
C) mesopause
D) stratosphere
E) troposphere

D

Why does ozone not form in high concentrations in the atmosphere above 50 km?
A) Insufficient oxygen is available.
B) Insufficient molecules exist for removal of excess energy from ozone upon its formation.
C) Light of the required wavelength is not available at those altitudes.
D) Atomic oxygen concentration is too low at high altitudes.
E) The pressure is too high.

B

Of the reactions involved in the photodecomposition of ozone (shown below), which are photochemical?
1. O2 (g) + hν → O (g) + O (g)
2. O (g) + O2 (g) + M (g) → O3 (g) + M* (g)
3. O3 (g) + hν → O2 (g) + O (g)
4. O (g) + O (g) + M (g) → O2 (g) + M* (g)
A) 2 and 4
B) 1, 2, and 4
C) 1 and 3
D) 1 only
E) all of them

C

Of the reactions involved in the photodecomposition of ozone (shown below), which are exothermic?
1. O2 (g) + hν → O (g) + O (g)
2. O (g) + O2 (g) + M (g) → O3 (g) + M* (g)
3. O3 (g) + hν → O2 (g) + O (g)
4. O (g) + O (g) + M (g) → O2 (g) + M* (g)

A) 2 and 4
B) 1 and 3
C) 1, 2, and 4
D) 2 only
E) all of them

A

In the reactions involved in the photodecomposition of ozone (shown below), what does M symbolize?
1. O2 (g) + hν → O (g) + O (g)
2. O (g) + O2 (g) + M (g) → O3 (g) + M* (g)
3. O3 (g) + hν → O2 (g) + O (g)
4. O (g) + O (g) + M (g) → O2 (g) + M* (g)
A) mesosphere
B) metal
C) molybdenum
D) methane
E) molecule

E

Why are chlorofluorocarbons so damaging to the ozone layer when they are such stable molecules?
A) They contain a double bond that ozone readily attacks, resulting in the destruction of the ozone.
B) They are very light molecules that rapidly diffuse into the upper atmosphere and block the radiation that causes formation of ozone.
C) They are greenhouse gases that raise the temperature above the dissociation temperature of ozone.
D) The radiation in the stratosphere dissociates them producing chlorine atoms that catalytically destroy ozone.
E) CFCs do not damage the ozone.

D

Cl atoms formed via photolysis of C—Cl bonds of chlorofluorocarbons in the stratosphere are particularly effective in destroying ozone at these altitudes because ________.
A) Cl atoms absorb UV, which generate O atoms to react with O2 to produce ozone
B) Cl atoms catalytically convert O3 to O2
C) Cl atoms stoichiometrically convert O3 to O2
D) Cl atoms react with H atoms, which catalyze conversion of O2 to O3
E) Cl atoms react with N atoms, which catalyze conversion of O2 to O3

B

Select the substance that is thought to be partially responsible for depleting the concentration of ozone in the stratosphere.
A) CFCl3
B) CO2
C) O2
D) N2
E) He

A

In the past, CFCs were used in which of the following?
A) spray cans
B) plastic manufacturing
C) air conditioners
D) refrigerators
E) all of the above

E

Which one of the following is a source of carbon dioxide in the troposphere?
A) natural gas seepage
B) electrical discharges
C) fossil-fuel combustion
D) volcanic gases
E) forest fires

C

The source(s) of sulfur dioxide in the atmosphere is/are ________.
A) volcanic gases
B) forest fires
C) bacterial action
D) fossil-fuel combustion
E) all of the above

E

Of the following, only ________ does not result in the formation of acid rain.
A) carbon dioxide
B) nitrogen dioxide
C) sulfur dioxide
D) nitrogen monoxide
E) methane

E

Sulfur released into the troposphere arises from both natural and human activity. What is the ratio of human to natural sources of sulfur compounds?
A) 3:1
B) 2:1
C) 1:1
D) 1:2
E) 1:3

A

How does lime reduce sulfur dioxide emissions from the burning of coal?
A) It reacts with the sulfur dioxide to form calcium sulfite solid that can be precipitated.
B) It reduces the sulfur dioxide to elemental sulfur that is harmless to the environment.
C) It oxidizes the sulfur dioxide to tetrathionate that is highly water soluble so it can be scrubbed from the emission gases.
D) It catalyzes the conversion of sulfur dioxide to sulfur trioxide which is much less volatile and can be removed by condensation.
E) It converts SO2 to solid, elemental sulfur.

A

The cumulative result of carbon dioxide, methane, and ozone in the troposphere on atmospheric temperatures is referred to as ________.
A) acid rain
B) the greenhouse effect
C) photoionization
D) photochemical smog
E) photodissociation

B

Carbon dioxide contributes to atmospheric warming by ________.
A) absorbing incoming radiation from the sun and converting it to heat
B) absorbing radiation emitted from the surface of the earth preventing its loss to space
C) undergoing exothermic reactions extensively in the atmosphere
D) increasing the index of refraction of the atmosphere so that infrared radiation from the sun is refracted to the surface of the earth where it is converted to heat
E) reducing the concentration of CO in the atmosphere

B

Which one of the following substances found in the atmosphere will absorb radiation in the infrared portion of the spectrum?
A) N2
B) O2
C) Kr
D) H2O
E) He

D

Which gaseous sulfur compound combines with water to form the principal acidic constituent of acid rain?
A) SO4^2-
B) SO3
C) SO2
D) SO
E) H2S

B

The reaction that forms most of the acid in acid rain is ________.
A) SO2 (g) + H2O (l) → H2SO4 (aq)
B) SO2 (g) + H2O (l) → H2SO3 (aq)
C) H2S (g) + 2 O2 (g) → H2SO4 (l)
D) Cl2 (g) + H2O (l) → HCl (aq) + HClO (aq)
E) SO3 (g) + H2O (l) → H2SO4 (aq)

E

Incomplete combustion of carbon-containing materials occurs when ________.
A) there is insufficient oxygen to convert all of the carbon to carbon dioxide
B) there are sulfur impurities in the carbon-containing material
C) the carbon-containing material is a gas
D) the combustion flame is too hot
E) there is an excess of oxygen

A

What is meant by the salinity of seawater?
A) percent by mass of salt in seawater
B) mass in grams of dry salts present in 1 kg of seawater
C) molality of NaCl in seawater
D) osmotic pressure of seawater
E) molarity of NaCl in seawater

B

The concentration of Na in seawater is 0.470 M. How many grams of Na can be extracted from 10.0 kg of seawater if the recovery rate is 60.0%?
A) 0.470
B) 64.8
C) 4.70
D) 108
E) 43.2

B

A single individual typically uses the greatest quantity of water for ________.
A) flushing toilets
B) cooking
C) cleaning (bathing, laundering, and house cleaning)
D) watering lawns
E) drinking water

C

The main ionic constituent of sea water is ________.
A) Na+
B) Cl-
C) SO42-
D) Mg2+
E) Ca2+

B

To produce acceptable quality drinking water from seawater by desalination, the level of salt must be reduced ________ fold.
A) 10
B) 50
C) 70
D) 100
E) 120

C

The primary detrimental effect of the presence of large amounts of biodegradable organic materials in water is ________.
A) it causes death of bottom dwelling organisms because it agglutinates and settles to the bottom, poisoning bottom dwelling organisms
B) it causes oxygen depletion in the water
C) it rises to the surface and absorbs wavelengths needed by aquatic plants
D) it decomposes endothermically causing the temperature of the water to decrease below the limits within which most aquatic organisms can live
E) it causes the water to become murky

B

Which of the following is not a stage in water treatment?
A) coarse filtration
B) aeration
C) chlorination
D) distillation
E) settling

D

Chemical treatment of municipal water supplies commonly entails use of CaO, Al2(SO4)3, and Cl2. The purpose of adding CaO is to ________.
A) remove all HCO3- as solid CaCO3
B) remove all SO4^2- as solid CaSO4
C) remove all Cl- as solid CaCl2
D) selectively kill anaerobic (but not aerobic) bacteria
E) make the water slightly basic so that addition of Al2(SO4)3 will afford a gelatinous precipitate of Al(OH)3

E

Eutrophication of a lake is the process of ________.
A) rapid increase in the amount of dead and decaying plant matter in the lake as a result of excessive plant growth
B) rapid decline in the lake's pH due to acid rain
C) dissolved oxygen being depleted by an overpopulation of fish
D) stocking the lake with fish
E) restoration of the lake's dissolved oxygen supply by aerobic bacteria

A

The lime-soda process is ________ being added to water to cause precipitation of magnesium as Mg(OH)2 and is used for large-scale water-softening operations.
A) Fe2O3
B) Al(OH)3
C) CaO
D) Fe2MgO4
E) Na2O

C

Water containing high concentrations of ________ cations is called hard water.
A) Ca²⁺
B) Mg²⁺
C) Na⁺
D) K⁺
E) Ca²⁺ or Mg²⁺

E

THMs are ________.
A) non-toxic
B) natural
C) used in green chemistry
D) suspected carcinogens
E) atmospheric pollutants

D

Which of the following is classified as a supercritical fluid?
A) water
B) xylene
C) toluene
D) hydrogen peroxide
E) none of the above

A

The layer of the atmosphere that contains our weather is called the ________.
A) mesosphere
B) heterosphere
C) stratosphere
D) thermosphere
E) troposphere

E

Of the noble gases, ________ is present in highest concentration in dry air at sea level.
A) Ne
B) He
C) Xe
D) Kr
E) Ar

E

The dividing line between the troposphere and stratosphere is known as the ________.
A) mesosphere
B) tropopause
C) thermosphere
D) stratopause
E) mesopause

B

The pressure of the atmosphere ________.
A) increases with altitude
B) follows the same trend as temperature
C) decreases with altitude
D) follows the reverse trend as temperature
E) stays the same

C

What is/are the product(s) of photodissociation of molecular oxygen?
A) molecular nitrogen
B) excited oxygen molecules
C) ozone
D) ozone and atomic oxygen
E) atomic oxygen

E

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

D

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

B

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

C

In the equation below, M is most likely ________.
O + O2 + M → O3 + M*

A) Br2
B) Xe
C) SO2
D) N2
E) H2O

D

Ozone is a(n) ________ of oxygen.
A) isomer
B) allotrope
C) isotope
D) resonance structure
E) atomic form

B

CFC stands for ________.
A) chlorinated freon compound
B) chlorofluorocarbon
C) carbonated fluorine compound
D) caustic fluorine carbohydrate
E) carbofluoro compound

B

Natural, unpolluted rainwater is typically acidic. What is the source of this natural acidity?
A) CO2
B) SO2
C) NO2
D) HCl
E) chlorofluorocarbons

A

What compound in limestone and marble is attacked by acid rain?
A) hydroxyapatite
B) calcium carbonate
C) gypsum
D) graphite
E) potassium hydroxide

B

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

A

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

C

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

C

Compounds found in fossil fuels that contain ________ are primarily responsible for acid rain.
A) sulfur
B) carbon
C) hydrogen
D) phosphorus
E) neon

A

Acid rain typically has a pH of about ________.
A) 7
B) 5
C) 4
D) 2
E) 1

C

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.

E

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, upper atmosphere

D

The brown color of photochemical smog over a city is mainly due to ________.
A) NO2
B) N2O4
C) CO
D) SO2
E) CO2

A

The concentration of which greenhouse gas has increased steadily over the last few decades?
A) H2O
B) CO
C) CO2
D) H2O2
E) O2

C

What is the percentage of freshwater on planet Earth?
A) 97%
B) 2.1%
C) 2.8%
D) 0.6%
E) 100%

D

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

C

The sterilizing action of chlorine in water is due to what substance?
A) Cl-
B) Cl2
C) HCl
D) HClO
E) H+

D

The "scale" caused by hard water is ________.
A) calcium ions
B) sodium chloride
C) magnesium oxide
D) sodium ions
E) calcium carbonate

E

What is the total pressure (torr) inside a container that contains a gas at 3.18 × 103 ppm where its partial pressure is ?
A) 5.38 × 10^-3
B) 1.86 × 10^-4
C) 1.88 × 10³
D) 1.86 × 10^-10
E) 1.88 × 10⁹

D

Which of the following is (are) not a typical source of nitric oxide?
A) livestock emissions
B) atmospheric electrical discharges
C) internal combustion engines
D) combustion of organic matter
E) all of the above

A

The area of the Earth's atmosphere 50 - 85 km above the surface is called the ________.
A) mesosphere
B) thermosphere
C) troposphere
D) stratosphere
E) exosphere

A

What is the total pressure (torr) inside a container that contains a gas at 8.57 × 10³ ppm where its partial pressure is 1.87 torr?
A) 4.58 × 10⁹
B) 1.60 × 10^-2
C) 2.18 × 10^-4
D) 218
E) 0.218

D

What is the wavelength of a photon with just enough energy to break a C-Cl bond? (The bond energy of the C-Cl bond is 331 kJ/mole.)
A) 362 nm
B) 723 nm
C) 181 nm
D) 5.46 × 10³⁵ nm
E) 5.50 × 10^-19 nm

A

What is the concentration (ppm) of water vapor in a sample of air that has a partial pressure of water of 1.20 torr and a total pressure of air of 695 torr?
A) 1.7
B) 0.17
C) 5.8 × 10^-4
D) 1.7 × 10³
E) 0.58

D

The concentration of CO in a room is 7.2 ppm. If the total pressure is 695 torr, then the partial pressure of CO is ________ torr.
A) 5.0 × 10³
B) 5.0
C) 1.0 × 10⁴
D) 5.0 × 10^-3
E) 9.7 × 10⁷

D

The concentration of ozone in a sample of air that has a partial pressure of O3 of 0.53 torr and a total pressure of air of 695 torr is ________ ppm.
A) 7.6 × 10²
B) 0.76
C) 0.076
D) 1.3 × 10^-3
E) 1.3

A

The mole fraction of nitrogen in dry air near sea level is 0.78084, where the molar mass of nitrogen is 28.013. The partial pressure of nitrogen when the total atmospheric pressure (dry air) is 97.5 kPa is ________ kPa.
A) 126
B) 4.51
C) 77.0
D) 2.16 × 10³
E) 2.75

C

The concentration of carbon monoxide in a sample of air is 6.0 ppm. There are ________ molecules of CO in 1.00 L of this air at 755 torr and 23 °C.
A) 2.5 × 10^-7
B) 1.4 × 10²¹
C) 1.9 × 10¹⁸
D) 1.1 × 10²⁰
E) 1.5 × 10¹⁷

E

What is the concentration (ppm) of helium in the atmosphere if the mole fraction of helium in dry air near sea level is 0.00000524?
A) 5.24
B) 1.91 × 10¹¹
C) 5.24 × 10^-4
D) 5240
E) 5.24 × 10^-12

A

The mole fraction of nitrous oxide in dry air near sea level is 0.00000050. The concentration of nitrous oxide is ________ molecules per liter, assuming an atmospheric pressure of 739 torr and a temperature of 29.5 °C.
A) 1.5 × 10^-5
B) 2.0 × 10^-8
C) 1.2 × 10¹⁶
D) 8.9 × 10¹⁸
E) 1.2 × 10¹⁷

C

What is the partial pressure or oxygen (in torr) in the atmosphere when the atmospheric pressure is 755.0 torr?
A) 158
B) 590
C) 611
D) 7.55
E) 760

A

What is the partial pressure or nitrogen (in torr) in the atmosphere when the atmospheric pressure is 760.0 torr?
A) 159
B) 594
C) 611
D) 7.60
E) 760

B

What is the partial pressure or argon (in torr) in the atmosphere when the atmospheric pressure is 750.0 torr?
A) 157
B) 586
C) 611
D) 7.50
E) 760

D

The dissociation energy of N2 is 941 kJ/mol. The maximum wavelength of light that has enough energy per photon to dissociate the N2 molecule is ________ nm.
A) 3137
B) 1.27 × 10^-4
C) 1.27 × 10^-7
D) 1.27 × 10⁵
E) 127

E

The ionization energy of NO is 890 kJ/mol:

NO + hv → NO+ +

The maximum wavelength of light capable of causing the ionization of NO is ________ nm.
A) 2967
B) 1.35 × 10^-4
C) 1.35 × 10^-7
D) 134.5
E) 1.35 × 10⁵

D

The concentration of Br- in a sample of seawater is 5.3 × 10^-4 M. What is the concentration (ppm) of Br-?
A) 0.042
B) 0.53
C) 5.3
D) 42
E) 0.0053

D

What is the final stage in municipal water treatment?
A) treatment with ozone or chlorine
B) course filtration through a screen
C) addition of CaO/Al2(SO4)3 and settling
D) sand bed filtration
E) aeration

A

In the presence of oxygen, the nitrogen present in biodegradable material ends up mainly as ________.
A) NO3-
B) NO2
C) N2O
D) NH3
E) NH4+

A

Which one of the following is produced by anaerobic bacteria after decomposing biodegradable nitrogen-containing waste?
A) NH3
B) NO2
C) N2O
D) NO3-
E) NH4+

A

Which process in the Global Water Cycle involves the phase transition H2O(l)→H2O(g)?
A) evaporation from fresh water
B) fog drip
C) plant uptake
D) freshwater storage
E) snowmelt runoff to streams

A

Which choice is one of the suspected carcinogens by-products from water chlorination called THMs?
A) CHClBr2
B) Cl2
C) Br2
D) CH3OCH3
E) CH4

A

Which choice is not one of the Ionic Constituents of seawater typically present in concentrations greater than 1 ppm?
A) ClO4-
B) Sr²⁺
C) Na+
D) H3Bo3
E) Cl-

A

The acidic water of a lake (V = 4 × 10⁸ L) must be neutralized with lime, CaO. It will require a minimum of ________ grams of lime to adjust the pH from 5.6 to 6.5.
A) 2 × 10⁴
B) 5 × 10⁴
C) 1 × 10⁵
D) 3 × 10⁴
E) 5

A

Which of the following is not one of the 12 principles associated with green chemistry?
A) distribution of chemical by-products into oceans
B) less hazardous chemical syntheses
C) promotion of the use of catalysts
D) use of renewable feedstocks
E) inherently safer chemistry for accident prevention

A

The most abundant component of air is ________.

N2

The absorption of a photon which results in bond breaking is known as ________.

photodissociation

The concept that radiowave propagation was affected by the atmosphere of the earth was discovered by ________.

Marconi

In the equation below, what is the meaning of the asterisk?
O + O2 → O3*

indicates the ozone formed contains excess energy

The stratosphere contains approximately ________ of the earth's ozone.

90%

Show how a molecule of C2F2Cl2 can destroy two molecules of ozone, O3.

CF2Cl2 (g) + hν → CF2Cl (g) + Cl (g)
Cl (g) + O3 (g) → ClO (g) + O2 (g)
ClO (g) + hν → Cl (g) + O (g)
Cl (g) + O3 (g) → ClO (g) + O2 (g)
----------------------------------------------------------
C2F2Cl2 (g) + 2 O3 (g) → C2F2Cl (g) + ClO (g) + 2 O2 (g) + O (g)

________ and ________ are major contributors to the depletion of the ozone layer.

Nitrogen oxides, chlorofluorocarbons

Clean rainwater is ________ mainly due to the presence of carbon dioxide.

acidic

What is the approximate pH of acid rain?

4.0

The contribution of ________ to acid rain is via the production of H2SO4.

sulfur

What are the primary chemical pollutants that create acid rain?

sulfur dioxide, nitrogen oxides

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 ________.

nitrogen dioxide, oxygen, ozone

The salinity, density, and temperature of seawater varies with ________.

depth

The three most concentrated ions in seawater are ________.

chloride ions, sodium ions, and sulfate ions

The average pH of the oceans is ________.

8.0 - 8.3

How many liters of water does the average adult in the U.S. require?

2

The world's largest desalinization plant is in Saudi Arabia and uses the process of ________ to produce drinking water.

reverse osmosis

Organic material that bacteria are able to oxidize is known as ________.

biodegradable

In the purification of drinking water, the filtered water is made basic by adding ________, then particles and bacteria are captured by adding Al2(SO4)3.

CaO

When dealing with gases, the mass fraction and the mole fraction are the same.

false

The bond energy of oxygen is higher than that of nitrogen.

false

The total pressure of a component in a gas mixture is the product of its mole fraction and the partial mixture pressure.

false

Nitrogen oxides catalytically destroy ozone.

true

Ozone depletion from chlorofluorocarbons is chiefly due to the production of free chlorine.

true

Nitric oxide arises from internal combustion engines.

true

Sulfur compounds in the atmosphere are equally derived from natural sources and from human activity.

false

The greenhouse effect of a methane molecule far exceeds the effect of a carbon dioxide molecule.

true

The principal component of smog is sulfur dioxide.

false

Most fresh water in the U.S. is used for agriculture.

true

Municipal water treatment consists of five steps ending with chlorination.

true

Describe the process of reverse osmosis that is used to desalinate seawater.

Water is fed, at high pressure, through tubes of semipermeable material. The water passes through the tubing material and the ions do not.

How can the presence of biodegradable waste in a lake result in the death of fish in the lake?

Bacteria utilize oxygen to degrade the waste and deplete the oxygen in the lake water.

List two of the three major sources of nitrogen and phosphorus in water.

domestic sewage, runoff from agricultural land, runoff from livestock areas

Ozone is more efficient at killing bacteria in water, yet chlorine is used more commonly for that purpose in municipal water treatment. Why?

Ozone must be generated on site, whereas chlorine can be shipped in tanks as a liquefied gas.