Arrange the following carboxylic acids in decreasing order of their acidic character: (i) (ii) (iii) (iv) (v)

Step-by-step solution

The acidic strength of carboxylic acids depends on the stability of their conjugate base (carboxylate anion). 1. (v) 2,6-Dihydroxybenzoic acid : The conjugate base is highly stabilized by intramolecular hydrogen bonding from two ortho hydroxyl (-OH) groups. Additionally, the strong steric hindrance (ortho effect) forces the carboxylate group out of the plane of the benzene ring, preventing destabilizing resonance from the ring. This makes it the most acidic. 2. (ii) o-Hydroxybenzoic acid (Salicylic acid) : The conj