$$[\mathrm{H^+}] \times [\mathrm{OH^-}] = 10$$^{-14}$$ \ \mathrm{M}^2$$

Question 1

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

Accepted Answer

A buffer resists changes in pH by absorbing or releasing hydrogen ions.

Question 2

What is the pH of a solution with a hydrogen ion concentration of $$1 	imes 10$$^{-5}$$ M?

Accepted Answer

pH = 5

Question 3

Which of the following is a correct chemical equation for the dissociation of hydrochloric acid (HCl) in water?

Accepted Answer

$$\mathrm{HCl} + \mathrm{H_2O} \rightarrow \mathrm{H_3O^+} + \mathrm{Cl^-}$$

Question 4

A solution has a pH of 3. How many times more acidic is it compared to a solution with pH 6?

Accepted Answer

1000 times

Question 5

Which of the following substances is most likely to have a pH greater than 7?

Accepted Answer

Household soap

Question 6

What happens when an acid meets a base in an aqueous solution?

Accepted Answer

A salt and water are formed through neutralization.

Question 7

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

Accepted Answer

$$[\mathrm{H^+}] 	imes [\mathrm{OH^-}] = 10$$^{-14}$$ \ \mathrm{M}^2$$

Question 8

Which of the following best describes a base?

Accepted Answer

A substance that accepts H+ ions or releases OH- ions in solution.

Question 9

If the concentration of OH- ions in a solution is $$1 	imes 10$$^{-9}$$ M, what is the concentration of H+ ions?

Accepted Answer

$$1 	imes 10$$^{-5}$$ M

Question 10

Which of the following is an example of a buffer system in the human body?

Accepted Answer

Carbonic acid and bicarbonate ion

Question 11

A solution has a pH of 8. Which statement is true about this solution?

Accepted Answer

It is basic and has more OH- ions than H+ ions.

Question 12

Which of the following equations represents the dissociation of sulfuric acid ($$\mathrm{H_2SO_4}) in $$water?

Accepted Answer

$$\mathrm{H_2SO_4} + \mathrm{H_2O} \rightarrow \mathrm{H_3O^+} + \mathrm{$$HSO_4$$^-}$$

Question 13

Which of the following best explains why blood pH remains stable even when a small amount of acid is added?

Accepted Answer

Blood contains buffers that absorb excess H+ ions.

Question 14

Which of the following is a real-life example of a neutralization reaction?

Accepted Answer

Mixing hydrochloric acid with sodium hydroxide to form salt and water

Question 15

If a solution has a pH of 2, what is its hydrogen ion concentration?

Accepted Answer

$$1 	imes 10$$^{-2}$$ M

Question 16

Which of the following statements about the pH scale is correct?

Accepted Answer

The pH scale is logarithmic, so each unit change represents a tenfold change in H+ concentration.

Question 17

Which of the following is NOT a property of acids?

Accepted Answer

Increase the concentration of OH- ions

Question 18

A solution has a pH of 11. What is the concentration of H+ ions?

Accepted Answer

$$1 	imes 10$$^{-11}$$ M

Question 19

Which of the following best describes the effect of atmospheric CO2 on ocean pH?

Accepted Answer

CO2 decreases ocean pH by forming carbonic acid, which releases H+ ions.

Acids, Bases, and pH: Biological Importance and Chemical Principles

Study Guide - Practice Questions