What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 × 10⁻⁵ A)4.49 B)4.64 C)4.85 D)5.00 E)5.52

Question

Quizplus · Accepted Answer

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

pH = pKa + log([conjugate base]/[acid])

The pKa is given as 1.8 × 10^-5. 
The acid is CH3COOH and the conjugate base is CH3COO-.

plugging in the given values, we get:

pH = 4.74 + log([0.35]/[0.45])
pH = 4.64

Therefore, the answer is B) 4.64.

What Is the PH of a Buffer That Consists of 0.45