(a) Account for the following : (i) Allyl chloride is hydrolysed more readily than n-propyl chloride. (ii) Isocyanides are formed when alkyl halides are treated with silver cyanide. (iii) Methyl chloride reacts faster with $\text{OH}^-$ ion in $\text{S}_\text{N}2$ reaction than t-butyl chloride. OR (b) Complete the following reactions by writing the structural formulae of 'A' and 'B' : (i) $\text{CH}_3\text{CH} = \text{CH}_2 \xrightarrow[\text{Peroxide}]{\text{HBr}} \text{`A'} \xrightarrow{\text{aq. KOH}} \text{`B'}$ (ii) $\underset{|\\ \text{Cl}}{\text{CH}_3\text{CH}_2\text{CHCH}_3} \xrightarrow[\Delta]{\text{alc. KOH}} \text{`A'} \xrightarrow{\text{HBr}} \text{`B'}$ (iii) $\text{`A'} \xrightarrow{\text{Mg}} \text{CH}_3\text{CH}_2\text{MgCl} \xrightarrow[\text{H}^+]{\text{H}_2\text{O}} \text{`B'}$ (Main product)