Question

Which of the following statements is correct in the Kolbe's electrolysis?

• A. Hydrocarbons containing even number of carbon atoms produced at anode
• B. Hydrocarbons containing odd number of carbon atoms produced at anode
• C. Hydrocarbons containing even number of carbon atoms produced at cathode
• D. Hydrocarbons containing odd number of carbon atoms produced at cathode

Answer 1

Answer: (A)

During Kolbe's electrolysis hydrocarbons with even number of C-atoms are because Kolbe's electrolysis occurs as follows :
At anode

At cathode
$2 H _{2} O +2 e^{-} \longrightarrow 2 OH ^{-}+2 H ^{\circ}$
$2 H ^{\circ} \longrightarrow H _{2}(g)$
For example, In case of alkenes

As hydrocarbons are obtained by Kolbe's electrolysis via combination of two alkyl groups (i.e. $R-R$ ). Thus, it always give hydrocarbons in which $C$-atoms are present in even number at anode.