Why phenols are acidic in nature ?

Explanation

Out of alcohols and phenols, phenols are more acidic

(i) Phenol is a resonance hybrid of the following contributing structures :

Due to resonance , oxygen acquire some positive charge (II to IV). It will strongly attract the shared electrons of O-H bond towards itself and `H^(+)` ion is released.

Phenoxide ion is stabilised to a greater extent due to the dispersion of negative charge. Thus phenoxide ion is readily formed due to the dissociation of phenol. On the other liand neither alcohol nor alkoxide ion is resonance stabilised. Morcover alkyl group due to its + I effect increases the electron density on oxygen în alkoxide ion and thus destabilies it
`underset("Alcohol")(R-overset(..)underset(..)O-H)hArrRrarrunderset("Alkoxide ion")overset(..)underset(..)(O: )+H^(+)`
Thus alcohols do not dissociate to give `H^(+)` ion easily. Hence, phenol are more acidic than alcohols.