32.2.3—Acidity of phenol

Phenol can donate H⁺ to form a phenoxide ion. The negative charge in phenoxide is delocalised into the aromatic ring, making the conjugate base more stable than an alkoxide.

Greater conjugate-base stability makes proton loss more favourable, but phenol remains a weak acid: its aqueous equilibrium is far from complete.

Phenol reacts with NaOH to form sodium phenoxide, but it does not release CO₂ from aqueous sodium carbonate as a carboxylic acid does.

The oxygen–hydrogen bond is not acidic simply because oxygen is electronegative; the key comparison is the stability and delocalisation of the conjugate base.