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

$$0.5 \text{ mol/L} \times 2 \text{ L} = 1.0 \text{ mol}$$

Question 1

Which property of water is primarily responsible for the upward movement of water in plants against gravity?

Accepted Answer

Cohesion due to hydrogen bonding

Question 2

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice are more 'ordered,' making ice less dense than liquid water

Question 3

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

Accepted Answer

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

Question 4

Which of the following best explains why sweating cools the human body?

Accepted Answer

Evaporative cooling removes heat as water molecules with the highest kinetic energy leave as gas

Question 5

What would happen to the properties of water if oxygen and hydrogen had equal electronegativity?

Accepted Answer

Water would become nonpolar and lose its ability to form hydrogen bonds

Question 6

Which of the following statements about acids and bases is correct?

Accepted Answer

An acid increases the $$H^+$$ concentration of a solution

Question 7

Calculate the number of moles of NaCl needed to make 2 L of a 0.5 M solution.

Accepted Answer

$$0.5 	ext{ mol/L} 	imes 2 	ext{ L} = 1.0 	ext{ mol}$$

Question 8

Which property of water explains why coastal cities tend to have milder climates than inland cities?

Accepted Answer

Water’s high specific heat

Question 9

A hydrophobic substance placed in water will:

Accepted Answer

Aggregate together and not dissolve due to nonpolar bonds

Question 10

If the pH of a solution changes from 6 to 4, how does the hydrogen ion concentration change?

Accepted Answer

It increases by 100 times

Question 11

Which of the following best describes a buffer?

Accepted Answer

A substance that minimizes changes in $$[H^+]$$ and $$[OH^-] in a $$solution

Question 12

Why is water considered a versatile solvent?

Accepted Answer

Its polarity allows it to dissolve ionic and polar molecules

Question 13

Which of the following is a consequence of water’s high heat of vaporization for living organisms?

Accepted Answer

Evaporative cooling helps regulate body temperature

Question 14

A solution contains $$0.01 M$$ $$HCl$$, a strong acid. What is the pH of this solution?

Accepted Answer

$$pH = -\log(0.01) = 2$$

Question 15

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil molecules have relatively nonpolar bonds and are hydrophobic

Question 16

Which of the following is true about the relationship between temperature and kinetic energy?

Accepted Answer

Temperature represents the average kinetic energy of molecules

Question 17

What is the main threat to marine organisms caused by ocean acidification?

Accepted Answer

Decreased carbonate ion concentration, affecting calcification

Question 18

Which of the following best describes surface tension?

Accepted Answer

A measure of how difficult it is to break the surface of a liquid

Question 19

How does the structure of the water molecule contribute to its unique properties?

Accepted Answer

The polar covalent bonds and bent shape allow for hydrogen bonding

Question 20

Which of the following is the correct formula for calculating molarity?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Chapter 3: Water and Life – Properties, Functions, and Biological Importance

Study Guide - Practice Questions