$$pH = -\log(1 \times 10$$^{-5}$$) = 5$$

Question 1

Which property of water allows a raft spider to walk on the surface of a pond without sinking?

Accepted Answer

High surface tension

Question 2

Why does ice float on liquid water, and why is this important for aquatic life?

Accepted Answer

Ice is less dense than liquid water, preventing bodies of water from freezing solid and allowing life to survive underneath.

Question 3

Which of the following best explains why water is considered a 'universal solvent'?

Accepted Answer

Water is polar and can surround and dissolve many ionic and polar substances.

Question 4

A solution has a hydrogen ion concentration of $$1 	imes 10$$^{-5}$$ M. What is its pH?

Accepted Answer

$$pH = -\log(1 	imes 10$$^{-5}$$) = 5$$

Question 5

Which of the following scenarios best illustrates the concept of evaporative cooling?

Accepted Answer

Sweating during exercise helps lower body temperature as water evaporates from the skin.

Question 6

What is the main reason coastal areas have more stable temperatures than inland areas?

Accepted Answer

Water has a high specific heat, absorbing and releasing heat slowly.

Question 7

Which of the following best describes a buffer’s function in biological systems?

Accepted Answer

A buffer minimizes changes in pH by accepting or donating hydrogen ions.

Question 8

Which equation correctly represents the dissociation of water?

Accepted Answer

$$H_2O \rightleftharpoons H^+ + OH^-$$

Question 9

A solution with a pH of 3 is how many times more acidic than a solution with a pH of 6?

Accepted Answer

1000 times

Question 10

Which of the following is a real-world consequence of ocean acidification?

Accepted Answer

Harm to marine life and ecosystems due to the formation of carbonic acid from dissolved $$CO_2.$$

Question 11

Which property of water is most responsible for the upward movement of water from roots to leaves in plants?

Accepted Answer

Cohesion between water molecules and adhesion to vessel walls

Question 12

Which of the following best describes a hydrophobic substance?

Accepted Answer

A substance that is nonionic and has nonpolar covalent bonds

Question 13

What is the effect of burning fossil fuels on acid precipitation?

Accepted Answer

It releases sulfur oxides and nitrous oxides, which react with water to form strong acids.

Question 14

Which of the following equations correctly describes the formation of carbonic acid in the blood?

Accepted Answer

$$CO_2 + H_2O$$ \rightarrow H_2CO_3$$

Question 15

If the pH of a solution changes from 7 to 5, what happens to the hydrogen ion concentration?

Accepted Answer

It increases by 100 times.

Question 16

Which property of water helps stabilize the temperature of living organisms and large bodies of water?

Accepted Answer

High specific heat

Question 17

Which of the following best explains why polar molecules are soluble in water?

Accepted Answer

They form hydrogen bonds with water molecules.

Question 18

A buffer solution contains a weak acid and its corresponding base. What happens when a small amount of acid is added to this buffer?

Accepted Answer

The buffer accepts hydrogen ions, minimizing the change in pH.

Question 19

Which of the following is NOT a property of water that contributes to its importance for life?

Accepted Answer

Solid water is more dense than liquid water.

Water and Life: Properties of Water, Acids, Bases, and Environmental Impact

Study Guide - Practice Questions