Why M hydroxybenzoic acid is stronger than P hydroxybenzoic acid?

In case of p-hydroxybenzoic acid, the anion is destabilized by the +M effect of the hydroxy group lying on the p group. Whereas, in m-hydoxy benzoic acid, the hydroxy group does not provide +M effect to the C to which the acidic group is attached. Hence, m-hydoxy benzoic acid is stronger than its para derivative.

Is 4 hydroxybenzoic acid acidic?

4-Hydroxybenzoic acid

Names
log P	1.58
Acidity (pKa)	4.54
Hazards
Main hazards	Irritant

Why salicylic acid is most acidic?

The p- nitro Phenoxide is stabilised by resonance. But in the case of salicylic acid, the Salicylate ion is stabilised by intramolecular H- bonding , makes salicylic acid more acidic than p- nitro Phenol.

Why is ortho hydroxy benzoic acid more acidic than para isomer?

Ortho hydroxy benzoic acid is more acidic than it’s para isomer because the carboxylate ion in ortho hydroxy benzoic acid get stable with intermolecule H bonding. ….

Is hydroxybenzoic acid more acidic than salicylic acid?

NOTE- salicylic acid is eighteen times more acidic than benzoic acid whereas p- hydroxybenzoic acid is half as acidic.

Why are benzoic acids stronger than benzoics?

Nearly all o-substituted benzoic acids are stronger than the benzoic acid. Benzoic acid is a resonance hybrid, and so the carboxyl group is coplanar with the ring. Any o- substituent tends to prevent this coplanarity.

What is the intramolecular hydrogen bond in ortho-hydroxybenzoic acid?

The intramolecular hydrogen bond in ortho -hydroxybenzoic acid between the C O O X − and the – O H groups forms a six membered ring. Since this structure is very stable, the deprotonation of the acid is favoured and the compound is more acidic.