Question

When sodium acetate is added to acetic acid, the degree of dissociation of acetic acid:

• A. increases
• B. decreases
• C. does not change
• D. becomes zero

Answer 1

The correct option is B decreases

When sodium acetate is added to acetic acid, the degree of dissociation of acetic acid decreases due to the common ion effect.

Sodium acetate decomposes to provide acetate ion that is common to dissociation of acetic acid. This suppresses the dissociation of acetic acid.

$C{H}_3-COOH\rightleftharpoons C{H}_3-CO{O}^{-}+H^{+}$
$C{H}_3-COONa\to C{H}_3-CO{O}^{-}+N{a}^{+}$

Hence, option B is correct.