Ncert Exercises & Solutions

Assertion (A):	Nitration of benzene with nitric acid requires the use of concentrated sulphuric acid.
Reason (R):	The mixture of concentrated sulphuric acid and concentrated nitric acid produces the electrophile, NO₂⁺ .

1.	Both (A) and (R) are True and (R) is the correct explanation of (A).
2.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
3.	(A) is True but (R) is False.
4.	(A) is False but (R) is True.

Hint: Nitration mixture contains conc. H₂SO₄ and conc. HNO₃

In the nitration of benzene with nitric acid, sulphuric acid acts as a catalyst. It helps in the formation of electrophile i.e., nitronium ion

{NO}_{2}^{+}

The reaction is as follows:

{HNO}_{3} + H_{2} {SO}_{4} \to {NO}_{2}^{+} + 2 {HSO}_{4}^{-} + H_{3} O^{+}