Chemistry - GOC Question with Solution | TestHub

Conjugate bases : the benzoate is resonance-stabilised over two oxygens on a benzene ring ($\mathrm{p}{K}_{\mathrm{a}}$ 4.2); the acetate is resonance-stabilised over two oxygens without the phenyl group ($\mathrm{p}{K}_{\mathrm{a}}$ 4.76); the m-nitrophenoxide is a phenoxide stabilised inductively by the meta nitro group ($\mathrm{p}{K}_{\mathrm{a}}$ 8.3); the phenoxide is the least stabilised ($\mathrm{p}{K}_{\mathrm{a}}$ 9.95). So benzoic acid $>$ acetic acid $>$ m-nitrophenol $>$ phenol, i.e. I $>$ IV $>$ II $>$ III.