Give reasons for the following :
i. tertiary-Butyyl does not give benzoic acid on treatment with acidic `KMnO_(4)`.
ii. Normally benzene gives electrophilic substituion reaction rather than electrophilic addition reaction although it has a double bond.

Explanation

In order than an alkyl group attached to benzene ring may be oxidised to carboxyl group, the presence of atleast one `prop-hydrogen is necessary. For example, toluene is oxidised to benzoic acid. But tertiary butyl benzene has no `prop-hydrogen` atom. It is therefore, not oxidised to benzoic acid.