Question

Describe the preparation of alkenes by Kolbe's electrolytic method.

Answer 1

$2R-CO{O}^{-}N{a}^{+}+\underset{Kolb{e}^{\prime }sElectrolysis}{H_{2}O}\to R-R+2C{O}_2+H_2+2NaOH$

R is any alkyl group.

At anode : $2R-CO{O}^{-}\stackrel{-2e^{-}}{\to }2R-\stackrel{O}{\stackrel{||}{C}}-\underset{\bullet }{\ddot{O:}}\to 2\stackrel{\bullet }{R}+2C{O}_2$

$\dot{R}+\dot{R}\to R$

At cathode :

$2H_{2}O+e^{-}\to \overline{O}H+\dot{H}$

$2\dot{H}\to H_2\uparrow$