Question

To a 100 ml solution of 0.1 M CH₃COONa and 0.1 M CH₃COOH, 0.4 gm of solid NaOH was added. Assuming volume remains constant, calculate the change in pH value? Given that pK_a (CH₃COOH) = 4.74. 

 (a) 0.125 

(b) 0.225 

(c) 0.01 

(d) 0.872.

Answer 1

Correct option  (d) 0.872.

Explanation:

Before NaOH addition, 

pH = pK_a = 4.74 [Since [CH₃COO^– ] = [CH₃COOH]] 

The following reaction occurs due to NaOH addition.