AP Chemistrymediummcq1 pt
A buffer contains 0.10 M HA and 0.10 M A⁻. What is its pH? (pKa = 4.74)
A.4.74
B.7.00
C.4.44
D.5.04
Explanation
Core Concept
When [A⁻] = [HA], the Henderson–Hasselbalch log term is log(1) = 0, so pH = pKa = 4.74. Equal pair concentrations pin the pH at pKa.
Correct Answer
A4.74
More Unit 8: Acids and Bases practice questions
- mediumWhich mixture produces a buffer with pH closest to 9.0?
- mediumFor a weak acid, which approximation allows skipping the quadratic?
- mediumWhat is the pH of a solution after 0.0050 mol of HCl is added to 1.0 L of pure water?
- mediumIn the reaction HSO₄⁻ + H₂O ⇌ SO₄²⁻ + H₃O⁺, which species acts as a base?
- easyWhich of the following is the strongest base?
Practice more AP Chemistry questions with full explanations
Practice Unit 8: Acids and Bases Questions →