Question 1

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

Accepted Answer

Water's high surface tension due to hydrogen bonding

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 because hydrogen bonds keep water molecules farther apart in ice, insulating aquatic life below

Question 3

Which of the following best explains why water is an excellent solvent for ionic compounds like NaCl?

Accepted Answer

Water molecules are polar and can form hydration shells around ions, separating them

Question 4

Calculate the mass of NaCl (in grams) required to make 1.0 L of a 1.0 M solution. ($$Na = 23$$, $$Cl = 35.5)$$

Accepted Answer

$$58.5$$ grams$

Question 5

A solution has a pH of 7. If the $$[H^+] is $$decreased by a factor of 100, what is the new pH?

Accepted Answer

$$9$$

Question 6

Which of the following statements about hydrogen bonds in water is correct?

Accepted Answer

Hydrogen bonds form between the hydrogen atom of one water molecule and the oxygen atom of another

Question 7

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

Accepted Answer

Cohesion and adhesion due to hydrogen bonding

Question 8

What is the molarity ($$M) of a $$solution containing $$0.5$$ moles of glucose in $$2$$ liters of water?

Accepted Answer

$$0.25$$ $$M$$

Question 9

Which of the following substances is most likely to be hydrophobic?

Accepted Answer

Olive oil

Question 10

Which equation correctly represents the dissociation of water?

Accepted Answer

$$2H_2O \rightleftharpoons H_3O^+ + OH^-$$

Question 11

How much NaOH would you need to make a 3.0 M solution in one liter of water? ($$Na = 23$$, $$O = 16$$, $$H = 1)$$

Accepted Answer

$$60$$ grams$

Question 12

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

Accepted Answer

Evaporation of sweat absorbs heat as hydrogen bonds break

Question 13

A solution has a pH of 8. If the $$[H^+] is $$increased by a factor of 1,000, what is the new pH?

Accepted Answer

$$5$$

Question 14

Which of the following is NOT an emergent property of water that contributes to Earth's suitability for life?

Accepted Answer

High density of ice compared to liquid water

Question 15

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

Accepted Answer

Water’s polarity allows it to surround and separate Na+ and Cl– ions

Question 16

Which of the following solutions has the highest concentration of hydrogen ions ($$[H^+]$$)?

Accepted Answer

pH 2

Question 17

Which of the following is a correct statement about acids and bases?

Accepted Answer

Acids increase the $$[H^+] in a $$solution

Question 18

Which of the following best describes the relationship between $$[H^+]$$ and $$[OH^-] in $$pure water at 25°C?

Accepted Answer

$$[H^+] = [OH^-]$$

Question 19

Which of the following is a real-life consequence if ice were more dense than liquid water?

Accepted Answer

Lakes and oceans would freeze from the bottom up, threatening aquatic life

Water and Life: Properties, Solutions, and pH in Biological Systems

Study Guide - Practice Questions