Consider the acidity of the carboxylic acids:
(1) `PhCOOH`
(2) `o-NO_(2) C_(6) H_(4) COOH`
(3) `p-NO_(2) C_(6) H_(4) COOH`
(4) `m-NO_(2) C_(6) H_(4) COOH`
Which of the following order is correct?

Options

A. `(I) gt (II) gt (III) gt (IV)`
B. `(II) gt (IV gt (III) gt (I)`
C. `(II) gt (IV) gt (I)gt (III)`
D. `(II) gt (III) gt IV) gt (I)`

Answer

D

Explanation

`-NO_(2)^(-)` group at any position shows electron withdrawing effect. Thus, acidic strenght is increases. But due to o-effect (ii) maximum acidic strength.
Thus, the order of acidic strength is `(II) gt (III) gt (IV) gt (I)`