Question

Alcohol act as an acid as well as base how?

Answer 1

Dear Student,

Alcohol is amphoteric in nature i.e. it can acts as an acid as well as a base.
Alcohol acts as a base as it can accept H⁺ from mineral acids as well as water. Also, due to the presence of highly electronegative O atom, the bond between O-H is weak as the electron pair is attracted more by O and therefore, the H⁺ ion can be donated easily thereby making alcohol an acid. However, it acts as a weak acid due to the presence of strong conjugate base RO^-. Stronger the conjugate base, weaker is the acid.
$$\begin{gathered} \mathrm{ROH}+{\mathrm{H}}_3{\mathrm{O}}^{+}\to \mathrm{R}\stackrel{+}{\mathrm{O}}{\mathrm{H}}_2+{\mathrm{H}}_2\mathrm{O} \\ \mathrm{Base} \\ \mathrm{ROH}+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{RO}}^{-}+{\mathrm{H}}_3{\mathrm{O}}^{+} \\ \mathrm{Acid} \end{gathered}$$