Explain the mechanism for the nitration of benzene.

(N/A) The nitration of benzene is an electrophilic aromatic substitution reaction. The mechanism involves three main steps:
$1$. Generation of the electrophile: The reaction between concentrated $HNO_3$ and concentrated $H_2SO_4$ generates the nitronium ion $(NO_2^+)$,which acts as the electrophile.
$HNO_3 + 2H_2SO_4 \rightarrow NO_2^+ + H_3O^+ + 2HSO_4^-$
$2$. Formation of the carbocation intermediate (arenium ion): The electrophile $(NO_2^+)$ attacks the benzene ring to form a resonance-stabilized carbocation,known as the sigma complex or arenium ion.
$3$. Removal of the proton: The base $(HSO_4^-)$ removes a proton from the $sp^3$ hybridized carbon of the arenium ion to restore the aromaticity of the ring,resulting in the formation of nitrobenzene.