Chemistry - GOC Question with Solution | TestHub

Presence of electron attracting group like${\mathrm{NO}}_2,-\mathrm{Cl}$ increases the acidity of phenol as it enables the ring to draw more electrons from the phenoxy oxygen and thus releasing easily the proton. Presence of electron releasing group e.g. $-{\mathrm{OCH}}_3$ on benzene sing decreases the acidity of phenol as it strengthens the negative charge on phenoxy oxygen and thus proton release becomes difficult. Further phenols are much more acidic than alcohols. The acidic nature of phenol is due to the formation of stable phenoxide ion in solution. ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OH}+{\mathrm{H}}_2\mathrm{O}\rightleftharpoons {\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{O}}^{-}+{\mathrm{H}}_3{\mathrm{O}}^{+}$ No resonance is possible in alkoxide ions $\left({\mathrm{RO}}^{-}\right)$derived from alcohols. The negative charge is localized on oxygen atom. Thus alcohols are not acidic.