Pre-Test

Chapter 3: Water and the Fitness of the Environment

Pre-Test

1 .

Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemical bonds known as _____. (Concept 3.1

) [Hint]

hydrogen bonds

ionic bonds

polar covalent bonds

nonpolar covalent bonds

none of the above

2 .

Most of water's unique properties result from the fact that water molecules _____. (Concept 3.1

) [Hint]

are very small

tend to repel each other

are extremely large

are electrically attracted to each other

are in constant motion

3 .

The amount of energy that must be absorbed or lost to raise or lower the temperature of 1 g of liquid water by 1°C _____. (Concept 3.2

) [Hint]

depends on the initial temperature of the water sample

is 1 kilocalorie

is 1,000 kilocalories

is 1 calorie

is 1,000 calories

is 1,000 joules

4 .

Ice floats because _____. (Concept 3.2

) [Hint]

it is colder than liquid water

its molecules are moving faster than in liquid water

it is denser than liquid water

its hydrogen molecules bond to the water surface film

its water molecules are farther apart than in liquid water

5 .

Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be _____. (Concept 3.2

) [Hint]

a solution

a solvent

a solute

an aqueous solution

an aqueous solvent

6 .

If the molecular mass of a carbon atom is 12, the mass of a hydrogen atom is 1, and the mass of an oxygen atom is 16 daltons, how many molecules does one mole of sugar (C₁₂H₂₂O₁₁) contain? (Concept 3.1

) [Hint]

45

342

6.02 x 10²³

(6.02 x 10²³)(342)

none of the above

7 .

An acid is a substance that _____. (Concept 3.3

) [Hint]

contains hydrogen

forms covalent bonds with other substances

increases the hydrogen ion concentration of an aqueous solution

is a versatile solvent

reduces the hydrogen ion concentration of a solution

8 .

A pH of 6 is how many times more acidic than a pH of 9? (Concept 3.3

) [Hint]

3

30

100

300

1,000

9 .

Select the statement that best describes a buffer. (Concept 3.3

) [Hint]

A buffer accepts hydrogen ions when they are in excess and donates hydrogen ions when they have been depleted.

A buffer causes acidic solutions to become alkaline, and alkaline solutions to become acidic.

A buffer prevents the pH of a solution from changing when an acid or base is added.

A buffer stabilizes the pH of a solution by preventing acids or bases from dissociating.

Buffered solutions are always neutral, with a pH of 7.

10 .

Most acid precipitation results from the combination of ____ with water in the atmosphere, forming strong acids that fall with rain or snow. (Concept 3.3

) [Hint]

sulfur oxides and nitrogen oxides

carbon dioxide

ozone

buffers

ammonium