Topic: Electrophilic substitution: halogenation, nitration, Friedel-Crafts· Hydrocarbons

Consider the nitration of benzene using mixed conc. H_2SO_4 and HNO_3. If a large amount of KHSO_4 is added to the mixture, the rate of nitration will be :

1. faster

2. slower

3. unchanged

4. doubled

Doubtly Asked 30 Oct 2026 NEET UG 2016 Phase 1 Practice test neet Save WhatsApp Report

1 answer

Best answer

Answer: 2. slower

Key idea: nitration needs the nitronium ion, formed by

$$\mathrm{HNO_3+2H_2SO_4\rightleftharpoons NO_2^++H_3O^++2HSO_4^-}$$

$\mathrm{KHSO_4}$ adds a large amount of $\mathrm{HSO_4^-}$ (common ion). By Le Chatelier's principle, the equilibrium shifts back, so less $\mathrm{NO_2^+}$ forms and the rate of nitration becomes slower.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

Was this answer helpful?

Consider the nitration of benzene using mixed conc. H_2SO_4 and HNO_3. If a large amount of KHSO_4 is added to the mixture, the rate of nitration will be :

1 answer

Your answer