Question

When sodium acetate $\left(C{H}_{3}COONa\right)$ is added to aqueous solution of acetic acid $\left(C{H}_{3}COOH\right)$

• A. $pH$ value become zero
• B. $pH$ value remains unchanged
• C. $pH$ value decreases
• D. $pH$ value increases

Answer 1

The correct option is D $pH$ value increases

When we add $C{H}_{3}COONa$ (which is a strong electrolyte), which ionizes as

$C{H}_{3}COONa\to C{H}_{3}CO{O}^{-}+N{a}^{+}$

So the concentration of $C{H}_{3}CO{O}^{-}$ ion increases. So the backward reaction takes place leading to the association of $C{H}_{3}CO{O}^{-}$ ion and $H^{+}$ ion to form undissociated Acetic Acid $C{H}_{3}COOH.$

So to summarize the addition of Sodium acetate to Acetic Acid, the concentration of $H^{+}$ ion will decrease. So pH increases.