Question

Arrange the following compounds in the increasing order of their acid strength:
p-cresol, p-nitrophenol, phenol

Answer 1

In p-nitrophenol, nitro group shows $-M$ effect which stabilises the conjugate anion hence, it will be most acidic.

In p-cresol, methyl group shows $+H$ effect which destabilises the conjugate anion hence, it will be least acidic.

Therefore, acidity order wil be:

p-cresol < phenol < p-nitrophenol