Explain how does the `(---OH)` group attached to a carbon of benzene ring activate it towards electophililc substitution.

Explanation

Phenolis senance by rid of the following structures :

As a result of +R effect of the OH group, the electroa density in the benering in and thereby fcilitating the stack of the electrophile Henes, presence of OH group activate the benzene ring towards electrophile subtitution reaction Thus, bonuse the OH group is an activating group, the reactions oeur at a faster me than reactions of benen itself. Further, it is clear from the resonating stratures, the election density la relatively higher at and P-positions and therefore, electrophilic substitution occur preferentially at s-and-positions. Thus, the-OH group is ortho-pare directing and therefore, imemine roup comes alarther position