Chemistry Test Acids and Bases 3

Question 1

Which of the following salts produces a basic solution when dissolved in water?

Accepted Answer

Na₂CO₃

Answer

Na₂CO₃ is a salt of a strong base (NaOH) and a weak acid (H₂CO₃), so CO₃²⁻ hydrolyzes to produce OH⁻.

Question 2

The Henderson–Hasselbalch equation is used to:

Accepted Answer

Determine the pH of a buffer solution

Answer

The Henderson–Hasselbalch equation, pH = pKa + log([A⁻]/[HA]), calculates the pH of buffer solutions.

Question 3

Which process describes autoionization of water?

Accepted Answer

2H₂O ⇌ H₃O⁺ + OH⁻

Answer

Water undergoes autoionization where two water molecules form hydronium and hydroxide ions in equilibrium.

Question 4

Which of the following is the strongest acid?

Accepted Answer

HClO₄ (completely dissociates)

Answer

HClO₄ (perchloric acid) is a strong acid that completely dissociates, making it stronger than any weak acid.

Question 5

What happens to the pH of a buffer when a small amount of strong acid is added?

Accepted Answer

It remains essentially unchanged

Answer

The conjugate base component of the buffer neutralizes the added acid, keeping pH nearly constant.

Chemistry Practice Test