Acid-Base Chemistry Quiz

Identify the correct conjugate base of H₂PO₄⁻:

• H₃PO₄

• HPO₄²⁻

• PO₄³⁻

• H₂PO₃⁻

Which of the following compounds can act as both a Brønsted base and a Lewis base?

• HCl

• NH₃

• BF₃

• H₃O⁺

Which of the following correctly compares the acid strength of HF, HCl, and HBr in water?

• HF > HCl > HBr

• HCl > HBr > HF

• HBr > HCl > HF

• HCl > HF > HBr

The Ka of a weak acid HA is 1.8 × 10⁻⁵. What is the pKa?

• 4.74

• 5.20

• 6.30

• 4.20

A 0.1 M solution of a weak acid has a pH of 3. What is the Ka of the acid?

• 1 × 10⁻⁴

• 1 × 10⁻⁵

• 1 × 10⁻⁶

• 3 × 10⁻⁴

Which of the following salts will produce a solution with pH > 7 due to hydrolysis?

• NH₄NO₃

• K₂SO₄

• Na₂CO₃

• KCl

A solution contains 0.1 M CH₃COOH and 0.1 M CH₃COONa. What is the pH? (Ka of acetic acid = 1.8 × 10⁻⁵)

• 4.74

• 7

• 9.26

• 3.74

The Kb of NH₃ is 1.8 × 10⁻⁵. What is the pH of a 0.1 M NH₃ solution?

• 11.13

• 9.26

• 8.75

• 10.08

Which of the following is NOT a correct conjugate acid-base pair?

• H₂O / OH⁻

• HNO₃ / NO₃⁻

• NH₄⁺ / NH₂⁻

• H₂CO₃ / HCO₃⁻

The hydrolysis constant (Kh) for NH₄Cl is approximately 5.5 × 10⁻¹⁰. What can be inferred?

• NH₄⁺ undergoes hydrolysis and makes the solution acidic

• Cl⁻ undergoes hydrolysis and makes the solution basic

• The solution is strongly basic

• The salt is neutral