Question 1

Which of the following statements best explains why a solution with a pH of 3 is more acidic than a solution with a pH of 5?

Accepted Answer

A solution with a pH of 3 has 100 times more $$\mathrm{H^+}$$ ions than a solution with a pH of 5.

Question 2

Which property is shared by both acids and bases?

Accepted Answer

They both can conduct electricity.

Question 3

A student adds hydrochloric acid ($$\mathrm{HCl}) to $$water. What happens at the molecular level?

Accepted Answer

$$\mathrm{HCl}$$ completely dissociates into $$\mathrm{H^+}$$ and $$\mathrm{Cl^-}$$ ions.

Question 4

Which of the following is a correct real-life example of a weak acid?

Accepted Answer

Acetic acid in vinegar

Question 5

What is the main function of a buffer in a biological system?

Accepted Answer

To resist changes in pH by absorbing excess $$\mathrm{H^+} or$$ $$\mathrm{OH^-}$$ ions

Question 6

A solution has a pH of 8. Which of the following best describes this solution?

Accepted Answer

It is basic and has more $$\mathrm{OH^-}$$ ions than $$\mathrm{H^+}$$ ions.

Question 7

Which of the following best describes the process of neutralization?

Accepted Answer

An acid reacts with a base to form water and a salt.

Question 8

Why is it important for blood to maintain a pH near 7.35–7.45?

Accepted Answer

Enzyme activity and cellular processes require a stable, near-neutral pH.

Question 9

Which of the following is NOT a property of bases?

Accepted Answer

They react strongly with metals.

Question 10

If a solution has a $$\mathrm{[H^+]}$$ concentration of $$1 	imes 10$$^{-4}$$ M, what is its pH?

Accepted Answer

$$4$$

Question 11

Which of the following best explains why strong acids are more dangerous than weak acids at the same concentration?

Accepted Answer

Strong acids completely dissociate in water, releasing more $$\mathrm{H^+}$$ ions.

Question 12

A cleaning product contains sodium hydroxide ($$\mathrm{NaOH}). $$Which property of bases makes it effective for cleaning grease?

Accepted Answer

The $$\mathrm{OH^-}$$ ions interact strongly with dirt and grease, breaking them down.

Question 13

Which of the following is a correct example of a salt formed by an acid-base reaction?

Accepted Answer

Sodium chloride ($$\mathrm{NaCl})$$

Question 14

Which of the following best describes the role of calcium carbonate ($$\mathrm{$$CaCO_3$$}) in $$antacids?

Accepted Answer

It acts as a buffer, neutralizing excess stomach acid.

Question 15

If you mix equal volumes of a strong acid and a strong base, what is the expected pH of the resulting solution?

Accepted Answer

Approximately 7, because the acid and base neutralize each other.

Question 16

Which of the following best explains why buffers are 'used up' after neutralizing excess acid or base?

Accepted Answer

The buffer's chemical components are consumed in the reaction and can no longer absorb more $$\mathrm{H^+} or$$ $$\mathrm{OH^-}$$ ions.

Question 17

Which of the following is a correct statement about the dissociation of water?

Accepted Answer

$$\mathrm{H_2O} \rightleftharpoons \mathrm{H^+} + \mathrm{OH^-}$$

Question 18

A solution turns blue litmus paper red and conducts electricity. Which of the following is most likely true about this solution?

Accepted Answer

It is an acid.

Question 19

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

Accepted Answer

$$\mathrm{[H^+]} = \mathrm{[OH^-]}$$

Question 20

Which of the following is a correct statement about the pH scale?

Accepted Answer

Each unit change in pH represents a tenfold change in $$\mathrm{[H^+]}$$ concentration.

Acids and Bases: Properties, Reactions, and Biological Importance

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