The ionisation constant of phenol is higher than that of ethanol because
(a) phenoxide ion is bulkier than ethoxide
(b) phenoxide ion is stronger base than ethoxide
(c) phenoxide ion is stabilised through delocalisation
(d) phenoxide ion is less stable than ethoxide
(c) Resonance stabilisation of phenoxide ion
Phenoxide ion is more stable than ethoxide ion due to resonance. Therefore, ionisation constant of phenol is higher than ethanol.