Question 1

Which property of water allows the seal in the image to survive in cold environments where ice floats on liquid water?

Accepted Answer

Ice is less dense than liquid water

Question 2

Refer to the molecular diagram of water. What type of bond is represented by the dotted lines between the water molecules?

Accepted Answer

Hydrogen bond

Question 3

Which of the following best explains why water has a high surface tension?

Accepted Answer

Hydrogen bonds hold water molecules together at the surface

Question 4

A solution has a hydroxide ion concentration of $$[OH^-] = 10$$^{-3}$$ M. What is the pH of this solution?

Accepted Answer

$$pH = 11$$

Question 5

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds form between a partially positive hydrogen and a partially negative atom

Question 6

Why is water considered a versatile solvent?

Accepted Answer

Its polar molecules are attracted to ions and other polar substances

Question 7

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

Accepted Answer

A buffer is an acid-base pair that resists changes in pH by reversibly binding hydrogen ions

Question 8

What happens to the hydrogen ion concentration $$[H^+]$$ when a base is added to an aqueous solution?

Accepted Answer

$$[H^+]$$ decreases

Question 9

Which property of water is most important for evaporative cooling in humans?

Accepted Answer

Water's high heat of vaporization

Question 10

If the pH of a solution changes from 6 to 4, what happens to the hydrogen ion concentration?

Accepted Answer

It increases by a factor of 100

Question 11

Why does ocean acidification threaten marine organisms that rely on calcification?

Accepted Answer

It decreases the concentration of carbonate ions needed for shell formation

Question 12

Which of the following best describes a hydrophilic substance?

Accepted Answer

A substance that has an affinity for water

Question 13

A solution contains $$0.5$$ moles of NaCl dissolved in $$1$$ liter of water. What is the molarity of the solution?

Accepted Answer

$$0.5 M$$

Question 14

Which of the following is a direct consequence of water's high specific heat for life on Earth?

Accepted Answer

Stable temperatures in oceans and lakes

Question 15

Which equation correctly expresses the relationship between pH and hydrogen ion concentration?

Accepted Answer

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

Question 16

Which of the following scenarios best illustrates the concept of cohesion in water?

Accepted Answer

A water strider walking on the surface of a pond

Question 17

Which of the following is NOT an emergent property of water that supports life on Earth?

Accepted Answer

Low heat of vaporization

Question 18

Which of the following best explains why salt (NaCl) dissolves easily in water?

Accepted Answer

The positive and negative regions of water molecules surround and separate the Na+ and Cl- ions

Question 19

A scientist adds a strong acid to a buffered solution. What will happen to the pH compared to an unbuffered solution?

Accepted Answer

The pH will remain relatively stable in the buffered solution

Question 20

Which of the following is true about acids and bases in aqueous solutions, as shown in the pH scale diagram?

Accepted Answer

Bases donate $$OH^- or $$accept $$H^+$$

Chapter 3: Water and Life – Key Concepts and Properties

Study Guide - Practice Questions