Question

Nitrobenzene can be prepared from benzene by using a mixture of conc. $HN{O}_3$ and conc. $H_{2}S{O}_4$
Then choose the correct statement regarding the mechansim of the reaction :

• A. $H_{2}S{O}_4$ acts as a base.
• B. $HN{O}_3$ acts as a base
• C. Both $H_{2}S{O}_4$ and $HN{O}_3$ acts as acids.
• D. None of the above

Answer 1

The correct option is B $HN{O}_3$ acts as a base

Electrophilic Substitution Mechanism for Nitration :
1. Generation of an electrophile $\stackrel{+}{N}{O}_2$
2. Formation of an arenium ion (intermediate).
3. Removal of proton $\left(H^{+}\right)$ from the arenium ion.

1. $H_{2}S{O}_4$ acts as an acid whereas $HN{O}_3$ acts as base as shown :