Question

A salt whose aqueous solution will have a pH of more than 7 will be:
(a) K₂CO₃
(b) K₂SO₄
(c) NaCl
(d) NH₄Cl

Answer 1

K₂CO₃
K₂CO₃ is formed from a weak acid, carbonic acid (H₂CO₃), and a strong base, potassium hydroxide (KOH). On hydrolysis, K₂CO₃ forms more OH^- ions than H⁺ ions. Thus, it is basic, with a pH more than 7.