Question 1

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

Accepted Answer

Cohesion

Question 2

Why does ice float on liquid water?

Accepted Answer

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

Question 3

Which equation correctly represents the relationship between hydrogen ion and hydroxide ion concentrations in pure water at 25°C?

Accepted Answer

$$[H^+][OH^-] = 10$$^{-14}$$

Question 4

A solution has a hydrogen ion concentration of $$[H^+] = 10$$^{-4}$$ M. What is its pH?

Accepted Answer

$$pH = 4$$

Question 5

Which of the following best explains why water has a high specific heat?

Accepted Answer

Hydrogen bonds between water molecules require significant energy to break

Question 6

What is the main function of buffers in biological systems?

Accepted Answer

Buffers minimize changes in concentrations of $$H^+$$ and $$OH^-$$ ions

Question 7

Which property of water allows insects to walk on its surface?

Accepted Answer

Surface tension

Question 8

If the pH of a solution changes from 7 to 5, how does the hydrogen ion concentration change?

Accepted Answer

It increases by 100 times

Question 9

Which of the following is a consequence if ice did not float on water?

Accepted Answer

Bodies of water would freeze solid, making life impossible on Earth

Question 10

What is the role of adhesion in water transport in plants?

Accepted Answer

It enables water molecules to stick to plant cell walls

Question 11

Which of the following best describes a hydrophobic substance?

Accepted Answer

A substance that does not have an affinity for water

Question 12

What is the effect of evaporative cooling on living organisms?

Accepted Answer

It stabilizes temperatures in organisms and bodies of water

Question 13

Which of the following is true about acids and bases?

Accepted Answer

Acids increase the $$H^+$$ concentration of a solution

Question 14

A solution with a pH of 9 is considered:

Accepted Answer

Basic

Question 15

Which of the following best explains why oil does not mix with water?

Accepted Answer

Oil molecules have relatively nonpolar bonds

Question 16

What is the main reason water is considered a versatile solvent?

Accepted Answer

Water is polar and can form hydration shells around ions

Question 17

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

Accepted Answer

Threats to water quality and marine life due to increased carbonic acid

Question 18

Which of the following is true about the dissociation of water molecules?

Accepted Answer

It is statistically rare but has a great effect on organisms

Question 19

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

Accepted Answer

$$pH = -\log [H^+]$$

Question 20

Which property of water helps minimize temperature fluctuations in environments suitable for life?

Accepted Answer

High specific heat

Chapter 3: Water and Life – Key Properties and Biological Importance

Study Guide - Practice Questions