Explain the mechanism of nitration of benzene .

Explanation

Nitration benzene reacts with a mixture of concentrated nitric acid and concentrated sulphuric acid at `50^(@)`C to form nitrobenzene.

Mechanism: This involves the following steps.
Step 1 : Generation of electrophile nitronium ion `NO_(2)^(+)`
`HNO_(3) + 2H_(2)SO_(4) rarr NO_(2)^(+) + H_(2)O^(+) + 2HSO_(4)^(-)`
Step 2 : The electrophile `NO_(2)^(+)` attacks the the benzene ring to form a carbocation which is resonance stabilized.

Step 3: Loss of a proton to give nitrobenzene. The proton is removed by `HSO_(4)^(-)`.