Explain the following with proper reasoning: (i) Although p-hydroxy benzoic acid is less acidic thanbenzoic acid but alpha-hydroxy benzoic acid (salicylic acid) is 15 times more acidic than benzoic acid. (ii) Oxidation of toluene by acidic KMnO_(4) gives poor yield of benzoic acid while oxidation of p-O_(2)NC_(6)H_(4)CH_(3) gives good yield of p-nitrobenzoic acid.

Explain the following with proper reasoning: (i) Although p-hydroxy b

1.	Explain the following with proper reasoning: (i) Although p-hydroxy benzoic acid is less acidic thanbenzoic acid but alpha-hydroxy benzoic acid (salicylic acid) is 15 times more acidic than benzoic acid. (ii) Oxidation of toluene by acidic KMnO_(4) gives poor yield of benzoic acid while oxidation of p-O_(2)NC_(6)H_(4)CH_(3) gives good yield of p-nitrobenzoic acid.
Answer» Solution :(i) Presence of -OH group (electron withdrawing) on BENZOIC acid decreases the acidic nature because negative charge on carboxylate ion DECREASE thereby MAKING carboxylate ion less stable. The resonance effectbeing stronger as compared to inductive effect, there is net increase in electron densifty at o-and p- positions, p-hydroxy benzoic acid is, therefore, less acidicthan benzoic acid. However, in o-hydroxy benzoic acid, there is intermolecular hydrogen bonding which STABILIZES o-hydroxy benzoate ion (conjugated base) to greater extent and thereby increasing acidic nature. This anomalous behaviour of groups when present m ortho-position is termed ortho effect. (ii) Oxidant is an electrophile, it can DESTROY the ring in case of toluene. But in para-nitrotoluene, the `-NO_(2)~ group deactivates the benzene ring and thus increases the yield of p-nitrobenzoic acid.