10.32 What happens when (i) N-butyl chloride is treated with alcoholic KOH (ii) Bromobenzene is treated with Mg in the presence of dry ether (iii) Chlorobenzene is subjected to hydrolysis (iv) Ethyl chloride is treated with aqueous KOH (v) Methyl bromide is treated with sodium in the presence of dry ether (vi) Methyl chloride is treated with KCN?

This is a classic question from the chapter Haloalkanes and Haloarenes. Let us solve each one as follows:

(1) When n - butyl chloride is treated with alcoholic KOH, the formation of but - l - ene takes place. This reaction is a dehydrohalogenation reaction.

$C{H}_3-C{H}_2-C{H}_2-C{H}_2-\mathrm{Cl}\underset{\text{KOH (alc), Δ}}{\overset{\text{Dehydrohalogenation}}{\to }}C{H}_3-C{H}_2-CH=C{H}_2+\mathrm{KCl}+H_{2}O$

When N-butyl chloride or 1-chlorobutane is