JEE Main 2026 — Jan 28, Shift 1 — Chemistry solution

JEE Main2026Jan 28, Shift 1Chemistry

Given below are two statements:

Statement I: Griss-Ilosvay test is used for the detection of nitrite ion, which involves the use of sulphanilic acid and $α$ -naphthylamine reagent.

Statement II: In the above test, sulphanilic acid is diazotized by the acidified nitrite ion, which on further coupling with $α$ -naphthylamine forms an azo-dye.

In the light of the above statements, choose the correct answer from the options given below

A
Statement I is false but Statement II is true
B
Both Statement I and Statement II are true
C
Statement I is true but Statement II is false
D
Both Statement I and Statement II are false

Solution

The Griss-Ilosvay reagent is the classical qualitative test for nitrite (NO $_{2}^{-}$ ).

Mechanism in two stages:

1. Acidified NO $_{2}^{-}$ generates HNO $_{2}$ , which diazotises sulphanilic acid to form the corresponding diazonium salt.

2. The diazonium salt couples with $α$ -naphthylamine to give a red azo dye, confirming the presence of nitrite.

Both the reagents listed in Statement I and the mechanism described in Statement II are correct. $∴$ Option (2).

← Back to full paper

Practice more Chemistry

Concept-wise practice with instant solutions on Fundamenthol.

Start practicing →