Question

Benzene react with nitrating mixture (conc. $HN{O}_3$ and conc $H_{2}S{O}_4.$ ) to produce nitrobenzene. In the nitrating mixture, $HN{O}_3$ acts as a

• A. Base
• B. Acid
• C. Reducing agent
• D. Catalyst

Answer 1

Answer: (A)

${\text{NO}}_{\text{2}}^{\text{+}}$ generated as follows:
${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\text{+}{\text{HNO}}_{\text{3}}\to {\text{HSO}}_{\text{4}}^{-}\text{+}{\text{H}}_{\text{2}}{\text{NO}}_{\text{3}}^{\text{+}}$
${\left(\text{O}\right)}_{\text{2}}\text{N}-\stackrel{\oplus }{{\left(\text{OH}\right)}_{\text{2}}}\to \underset{\text{(nitronium}\text{ion)}}{{\text{NO}}_{\text{2}}^{\text{+}}{\left(\text{+H}\right)}_{\text{2}}\text{O}}$
Here, ${\text{HNO}}_{\text{3}}$ accept ${\text{H}}^{\oplus }$ , hence, act as base.