Consider the acidity of the carboxylic acids:

(1) $\mathrm{PhCOOH}$

(2) $\mathrm{o}-{\mathrm{NO}}_2{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{COOH}$

(3) $\mathrm{p}-{\mathrm{NO}}_2{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{COOH}$

(4) $\mathrm{m}-{\mathrm{NO}}_2{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{COOH}$

Which of the following order is correct?

Electron withdrawing group increases the acidic nature of benzoic acid, o-isomer will have higher acidic nature than -p position have more pronounce electron-withdrawing effect than NO₂ group at -m position.

Hence the order of acidity is    2 > 3 > 4 > 1