Question

Give one example of a salt which gives an aqueous solution having:

 pH less than 7

Answer 1

NH4Cl is formed from a weak base, ammonium hydroxide (NH₄OH), and a strong acid, hydrochloric acid (HCl). On hydrolysis, NH₄Cl forms more H⁺ ions than OH^- ions. Thus, it is acidic, with a pH less than 7.