Question

When sodium acetate is added to an aqueous solution of acetic acid :

• A. The pH of the solution decreases
• B. The pH of the solution increases
• C. The pH of the solution remains unchanged
• D. An acid salt is produced

Answer 1

The correct option is B The pH of the solution increases

Dissociation of $C{H}_{3}COOH$ is suppressed by the addition of sodium acetate $\left(C{H}_{3}COONa\right)$ due to common ion $\left(C{H}_{3}CO{O}^{-}\right)$ effect. The $\left[H^{+}\right]$ decreases raising the pH of the acid solution.
Note : After the addition of $C{H}_{3}COONa$ to $C{H}_{3}COOH$, a buffer solution is formed which has reserved pH value.