JEE Main 2022 · ChemistryMultiple choiceSingle correctEasyRecall

JEE Main 28 June 2022, Shift 1, Chemistry Q80

Question 80 of 90 in this shift, Chemistry question 20 of 30, Section A.

The formula of the purple colour formed in Laissaigne’s test for sulphur using sodium nitroprusside is

(1) $\mathrm{NaFe[Fe(CN)_6]}$
(2) $\mathrm{Na[Cr(NH_3)_2(NCS)_4]}$
(3) $\mathrm{Na_2[Fe(CN)_5(NO)]}$
(4) $\mathrm{Na_4[Fe(CN)_5(NOS)]}$ Official answer

Official answer

Option 4

NTA final key.

Chapter: Organic Chemistry: Some Basic Principles and Techniques
Topic: Anion Analysis
Idea tested: Sulfide Sodium Nitroprusside Test

Same idea in other shifts

Asked 4× in all

2 Apr 2025, Shift 2 · Q62Formation of $\mathrm{Na_4[Fe(CN)_5NOS]}$ , a purple coloured complex formed by addition of sodium nitroprusside in sodium carbonate…EasySingle correct
4 Aug 2021, Shift 2 · Q50The reagent that gives purple coloured complex with $\mathrm{S^{2-}}$ ion isEasySingle correct
26 Aug 2021, Shift 1 · Q41Which one of the following complexes is violet in colour ?MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.