Previous Year NEET Question- Alcohols L-4

Question: Among the following four compounds#

(i) Phenol

(ii) Methyl phenol

(iii) Meta-nitrophenol

(iv) Para-nitrophenol

The acidity order is

A) (iv) $>$ (iii) $>$ (i) $>$ (ii)

B) (iii) $>$ (iv) $>$ (i) $>$ (ii)

C) (i) $>$ (iv) $>$ (iii) $>$ (ii)

D) (ii) $>$ (i) $>$ (iii) $>$ (iv)

Answer: (iv) $>$ (iii) $>$ (i) $>$ (ii)#

Solution:#

In phenols, the presence of electron releasing groups decrease the acidity, whereas presence of electron withdrawing groups increase the acidity, compared to phenol.

Among the meta and para-nitrophenols, the latter is more acidic as the presence of $-\mathrm{NO}_2$ group at para position stabilises the phenoxide ion to a greater extent than when it is present at meta position. Thus, correct order of acidity is : $$ \text { (iv) }>\text { (iii) }>\text { (i) }>\text { (ii) } $$