Chemistry - GOC Question with Solution | TestHub

An ortho OH group stabilises the carboxylate by intramolecular hydrogen bonding, so salicylic acid (II) is stronger than benzoic acid (I). Compound (IV) has hydroxyls on both ortho positions, chelating the anion on both sides, and is the strongest. In (III) the OH is para, where it donates electron density by resonance toward the COOH group and destabilises the carboxylate, making (III) weaker than benzoic acid itself. Hence IV $>$ II $>$ I $>$ III.