The acidic or basic nature of a salt solution depends on the relative strengths of its parent acid and base .

Sodium acetate ($\text{CH}_3\text{COONa}$) is a salt formed from a weak acid (acetic acid, $\text{CH}_3\text{COOH}$) and a strong base (sodium hydroxide, $\text{NaOH}$). In an aqueous solution, it completely ionises, and the acetate ion undergoes anionic hydrolysis to produce hydroxyl ions: $\text{CH}_3\text{COO}^-(aq) + \text{H}_2\text{O}(l) \rightleftharpoons \text{CH}_3\text{COOH}(aq) + \text{OH}^-(aq)$ This process results in an increase in the concentration of $\text{OH}^-$ ions, making the solution alkaline or basic in nature (pH > 7) .

Conversely, ammonium chloride, ammonium sulphate, and ammonium nitrate are salts formed from a weak base ($\text{NH}_4\text{OH}$) and strong acids ($\text{HCl}$, $\text{H}_2\text{SO}_4$, and $\text{HNO}_3$, respectively). These undergo cationic hydrolysis to release $\text{H}^+$ ions, making their solutions acidic (pH < 7) .