Question

Among the following four compounds
(a) Phenol
(b) Methyl phenol
(c) Meta-nitrophenol
(d) Para-nitrophenol
the acidity order is -

• A. c > d > a > b
• B. a > d > c > b
• C. b > a > c > d
• D. d > c > a > b

Answer 1

Answer: (D)

An electron withdrawing group $(-1$ showing group like $-N{O}_2,-CN)$ stabilises the phenoxide ion, thus when present, increases the acidity of phenol. On the other hand electron releasing groups ( $+1$ showing group like $-C{H}_3-C_2{H}_5$ ), when present, decrease the acidity of phenol by destabilizing peroxide ion.