Q11 / 160 · AP EAMCET 2008 · Chemistry
Assertion (A) : The aqueous solution of $\mathrm{CH}_3 \mathrm{COONa}$ is alkaline in nature.
Reason (R) : Acetate ion undergoes anionic hydrolysis
The correct answer is
- Correct answerAboth $(A)$ and $(R)$ are true and (R) is the correct explanation of (A).
- Bboth $(A)$ and $(R)$ are true but (R) is not the correct explanation of (A).
- C(A) is true but (R) is not true.
- D(A) is not true but (R) is true.
Solution
$$
\mathrm{CH}_3 \mathrm{COONa}+\mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{CH}_3 \mathrm{COOH}+\mathrm{NaOH}
$$
The above process takes place in following steps
$$
\mathrm{CH}_3 \mathrm{COONa} \underset{\text { in aqueous solution }}{\stackrel{\text { Ionisation }}{\rightleftharpoons}} \mathrm{CH}_3 \mathrm{COOO}^{-}+\mathrm{Na}^{+}
$$
$$
\mathrm{CH}_3 \mathrm{COO}^{-}+\mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{CH}_3 \mathrm{COOH}+\mathrm{OH}^{-}
$$
Acetate ion undergoes anionic hydrolysis and the resulting solution is slightly basic due to excess of $\mathrm{OH}^{-}$ions. Hence, both (A) and (R) are true and $(R)$ is the correct explanation of (A).
Hence, the correct answer is option: 'A'.