1. What is the pH of a buffer that contains 0.15 M CH3COOH and 0.10 M NaCH3COO (Ka = 1.8 × 10–

Answer 1

To find the pH of the buffer solution, we need to use the Henderson-Hasselbalch equation:

pH = pKa + log ([A−]/[HA])

Given that Ka = 1.8 × 10^(-5) for CH3COOH, we can calculate pKa as follows:

pKa = -log(Ka) = -log(1.8 × 10^(-5)) ≈ 4.74

Plugging in the values into the Henderson-Hasselbalch equation:

pH = 4.74 + log (0.10/0.15)

pH = 4.74 + log (0.6667)

pH = 4.74 - 0.1761

pH ≈ 4.56

Therefore, the pH of the buffer solution containing 0.15 M CH3COOH and 0.10 M NaCH3COO is approximately 4.56.