$$[H^+] = 1 \times 10$$^{-4}$$\ \mathrm{M}$$

Question 1

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Ice is less dense than liquid water due to hydrogen bonds forming a lattice structure.

Question 2

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

Accepted Answer

Surface tension resulting from hydrogen bonding between water molecules.

Question 3

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$the solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$\ \mathrm{M}$$

Question 4

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

Accepted Answer

Hydrogen bonds between water molecules absorb heat when they break and release heat when they form.

Question 5

Which of the following is an emergent property of water that is essential for life on Earth?

Accepted Answer

Water's ability to moderate temperature due to its high specific heat.

Question 6

A beaker contains a mixture of oil and water. Which statement best explains why the oil forms a separate layer above the water?

Accepted Answer

Oil is hydrophobic and does not form hydrogen bonds with water.

Question 7

Which of the following reactions best represents the addition of a base to water?

Accepted Answer

$$\mathrm{NaOH} \rightarrow \mathrm{Na}^+ + \mathrm{OH}^-$$

Question 8

Which of the following statements about buffers is true?

Accepted Answer

They maintain a constant pH when acids or bases are added to them.

Question 9

What is the main reason water is called the 'universal solvent'?

Accepted Answer

Its polarity allows it to dissolve many ionic and polar substances.

Question 10

Which of the following best describes the effect of adding hydrochloric acid (HCl) to pure water?

Accepted Answer

It increases the concentration of $$\mathrm{H}^+$$ ions and decreases the pH.

Question 11

Which of the following best explains why lakes and oceans help moderate Earth's climate?

Accepted Answer

Water's high specific heat allows it to absorb and release large amounts of heat with little temperature change.

Question 12

Which of the following is true about the pH scale?

Accepted Answer

A solution with $$[H^+] = 1 	imes 10$$^{-7}$$\ \mathrm{M}$$ has a pH of 7.

Question 13

Which of the following best describes a homogeneous solution?

Accepted Answer

A solution in which all components are uniformly distributed.

Question 14

Which of the following is a direct result of water's high heat of vaporization?

Accepted Answer

Evaporation of sweat cools the body efficiently.

Question 15

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

Accepted Answer

The positive and negative ions of NaCl are surrounded by the oppositely charged regions of water molecules.

Question 16

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

Accepted Answer

Acids increase the concentration of $$\mathrm{H}^+$$ ions in solution.

Question 17

Which of the following best describes how buffers help maintain pH in biological systems?

Accepted Answer

By donating or accepting $$\mathrm{H}^+$$ ions as needed.

Question 18

Which of the following is NOT a property of water that results from hydrogen bonding?

Accepted Answer

Low boiling point.

Question 19

Which of the following best describes a hydrophilic molecule?

Accepted Answer

A molecule that easily dissolves in water.

Question 20

Which of the following would most likely increase the pH of a solution?

Accepted Answer

Adding a base, which decreases the concentration of $$\mathrm{H}^+$$ ions.

Properties of Water and Aqueous Chemistry

Study Guide - Practice Questions