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✓ Correct
(C)Statement I is true but Statement II is false
(D)Both Statement I and Statement II are false
Answer: (B)
Solution
The Griess\textendash Ilosvay test detects the nitrite ion using sulphanilic acid together with α-naphthylamine, so the first statement is correct. In acid the nitrite ion gives nitrous acid, which diazotises sulphanilic acid to a diazonium salt; this salt then couples with α-naphthylamine to form a red azo dye, which is exactly the mechanism described, so the second statement is correct and also correctly explains the test. Both statements are true.
JEE Main · 2026 · 28 Jan 2026 · Shift 1 · Single correct option
