iii. What is meant by hydrolysis ? A solution of CH3COONH4 is neutral. why ?

4. Answer the following :

Answer:- Hydrolysis of salt is defined as the reaction in which cations or anions or both ions of a salt react with ions of water to produce acidity or alkalinity (or sometimes even neutrality).

i. CH₃COONH₄ is a salt of a weak acid, CH₃COOH (\(K_a = 1.8 \times 10^{-5}\)), and a weak base, NH₄OH (\(K_b = 1.8 \times 10^{-5}\)). When the salt CH₃COONH₄ is dissolved in water, it undergoes hydrolysis:

\[\ce{CH3COO^-_{(aq)} + NH4^+_{(aq)} + H2O_{(l)} \rightleftharpoons CH3COOH_{(aq)} + NH4OH_{(aq)}}\]

ii. The ions of the salt react with water as

\[\ce{CH3COO^-_{(aq)} + H2O_{(l)} \rightleftharpoons CH3COOH_{(aq)} + OH^-_{(aq)}}\] …(1)

\[\ce{NH4^+_{(aq)} + 2H2O_{(l)} \rightleftharpoons NH4OH_{(aq)} + H3O^+_{(aq)}}\] …(2)

iii. As \(K_a = K_b\), the relative strength of acid and base produced in hydrolysis is the same.

iv. Therefore, the solution is neutral. Hydrolysis of NH₄⁺ produces as many H₃O⁺ ions as that of CH₃COO^– produces OH^– ions.