Question 1

Which type of bond must be broken for water to vaporize?

Accepted Answer

A)   ionic bonds
B)   both hydrogen bonds and ionic bonds
C)   polar covalent bonds
D)   hydrogen bonds
E)   both polar covalent bonds and hydrogen bonds D

Question 2

How many grams of acetic acid (C₂H₄O₂)would you use to make 10 L of a 0.1 M aqueous solution of acetic acid? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.)

Accepted Answer

A)   10 g
B)   0.1 g
C)   6.0 g
D)   60 g
E)   0.6 g D

Question 3

Increased atmospheric CO₂ concentrations might have what effect on seawater?

Accepted Answer

A)   Seawater will become more acidic, and bicarbonate concentrations will decrease.
B)   Seawater will become more alkaline, and carbonate concentrations will decrease.
C)   There will be no change in the pH of seawater, because carbonate will turn to bicarbonate.
D)   Seawater will become more acidic, and carbonate concentrations will decrease.
E)   Seawater will become more acidic, and carbonate concentrations will increase. D

Question 4

One idea to mitigate the effects of burning fossil fuels on atmospheric CO₂ concentrations is to pipe liquid CO₂ into the ocean at depths of 2,500 feet or greater. At the high pressures at such depths, CO₂ is heavier than water. What potential effects might result from implementing such a scheme?

Accepted Answer

A)   increased photosynthetic carbon fixation because of the increased dissolved carbon dioxide in the deep water
B)   increased carbonate concentrations in the deep waters
C)   reduced growth of corals from a change in the carbonate-bicarbonate equilibrium
D)   no effect because carbon dioxide is not soluble in water
E)   both increased acidity of the deep waters and changes in the growth of bottom-dwelling organisms with calcium carbonate shells

Question 5

If a solution has a pH of 7, this means that

Accepted Answer

A)   there are no H⁺ ions in the water.
B)   this is a solution of pure water.
C)   the concentration of H⁺ ions in the water equals the concentration of OH⁻ ions in the water.
D)   this is a solution of pure water, and the concentration of H⁺ ions in the water is 10⁻⁷ M.
E)   this is a solution of pure water, and the concentration of H⁺ ions equals the concentration of OH⁻ ions in the water.

Question 6

A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.)

Accepted Answer

A)   50°C
B)   5°C
C)   1°C
D)   100°C
E)   10°C

Question 7

How would acidification of seawater affect marine organisms?

Accepted Answer

A)   Acidification would increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals.
B)   Acidification would decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals.
C)   Acidification would increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals.
D)   Acidification would decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals.
E)   Acidification would increase dissolved bicarbonate concentrations, and cause increased calcification of corals and shellfish.

Question 8

-How many grams would be equal to 1 mol of the compound shown in the figure above?
(carbon = 12, oxygen = 16, hydrogen = 1)

Accepted Answer

A)   29
B)   30
C)   60
D)   150
E)   342

Question 9

Research indicates that acid precipitation can damage living organisms by

Accepted Answer

A)   buffering aquatic systems such as lakes and streams.
B)   decreasing the H⁺ concentration of lakes and streams.
C)   increasing the OH⁻ concentration of lakes and streams.
D)   washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth.
E)   both decreasing the H⁺ concentration of lakes and streams and increasing the OH⁻ concentration of lakes and streams.

Question 10

Which of the following is a hydrophobic material?

Accepted Answer

A)   paper
B)   table salt
C)   wax
D)   sugar
E)   pasta

Question 11

What is the hydrogen ion [H⁺] concentration of a solution of pH 8?

Accepted Answer

A)   8 M
B)   8 x 10⁻⁶ M
C)   0.01 M
D)   10⁻⁸ M
E)   10⁻⁶ M

Question 12

Identical heat lamps are arranged to shine on identical containers of water and methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 13

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?

Accepted Answer

A)   a covalent bond
B)   a hydrogen bond
C)   an ionic bond
D)   a hydrophilic bond
E)   a van der Waals interaction

Question 14

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that

Accepted Answer

A)   solution Y has no free hydrogen ions (H⁺) .
B)   the concentration of hydrogen ions in solution X is 30 times as great as the concentration of hydrogen ions in solution Y.
C)   the concentration of hydrogen ions in solution Y is 1,000 times as great as the concentration of hydrogen ions in solution X.
D)   the concentration of hydrogen ions in solution X is 3 times as great as the concentration of hydrogen ions in solution Y.
E)   the concentration of hydrogen ions in solution X is 1,000 times as great as the concentration of hydrogen ions in solution Y.

Question 15

Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H₂S

Accepted Answer

A)   will ionize more readily.
B)   will have greater cohesion to other molecules of H₂S.
C)   will have a greater tendency to form hydrogen bonds with each other.
D)   will have a higher capacity to absorb heat for the same change in temperature.
E)   will not form hydrogen bonds with each other.

Question 16

Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon?

Accepted Answer

A)   the change in density when it condenses to form a liquid or solid
B)   reactions with other atmospheric compounds
C)   the release of heat by the formation of hydrogen bonds
D)   the release of heat by the breaking of hydrogen bonds
E)   the high surface tension of water

Question 17

You have two beakers. One contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl)into each beaker. Predict what will happen.

Accepted Answer

A)   Equal amounts of NaCl crystals will dissolve in both water and methanol.
B)   NaCl crystals will NOT dissolve in either water or methanol.
C)   NaCl crystals will dissolve readily in water but will not dissolve in methanol.
D)   NaCl crystals will dissolve readily in methanol but will not dissolve in water.
E)   When the first crystals of NaCl are added to water or to methanol, they will not dissolve; but as more crystals are added, the crystals will begin to dissolve faster and faster.

Question 18

Which of the following statements is true about buffer solutions?

Accepted Answer

A)   They maintain a constant pH when bases are added to them but not when acids are added to them.
B)   They maintain a constant pH when acids are added to them but not when bases are added to them.
C)   They maintain a relatively constant pH of approximately 7 when either acids or bases are added to them.
D)   They maintain a relatively constant pH when either acids or bases are added to them.
E)   They are found only in living systems and biological fluids.

Question 19

-How many grams of the compound in the figure above would be required to make 2.5 L of a 1 M solution?
(carbon = 12, oxygen = 16, hydrogen = 1)

Accepted Answer

A)   29
B)   30
C)   60
D)   150
E)   342

Question 20

You have a freshly prepared 0.1 M solution of glucose in water. Each liter of this solution contains how many glucose molecules?

Accepted Answer

A)   6.02 × 10²³
B)   3.01 × 10²³
C)   6.02 × 10²⁴
D)   12.04 × 10²³
E)   6.02 × 10²²

Exam 3: Water and Life