Question

though melting and boiling points of sodium and potassium chlorides are high the alkali metals are obtained by the electrolytic reduction of their metal oxides.give reason

Answer 1

Dear Student,

Melting and boiling point of sodium and potassium chlorides are high due to the ionic bond present between them.
By electrolytic reduction, active metals like sodium, potassium, etc are extracted, The reaction taking place are:
$$\begin{gathered} \mathrm{NaCl}\leftrightarrow {\mathrm{Na}}^{+}+{\mathrm{Cl}}^{-} \\ {\mathrm{Na}}^{+}\mathrm{ions}\mathrm{move}\mathrm{towards}\mathrm{cathode}\mathrm{while}{\mathrm{Cl}}^{-}\mathrm{towards}\mathrm{anode}. \\ {\mathrm{Na}}^{+}+{\mathrm{e}}^{-}\to \mathrm{Na} \\ {\mathrm{Cl}}^{-}\to \mathrm{Cl}+{\mathrm{e}}^{-} \\ \mathrm{Cl}+\mathrm{Cl}\to {\mathrm{Cl}}_2 \end{gathered}$$