JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyCalculation

JEE Main 3 August 2021, Shift 2, Chemistry Q40

Question 40 of 90 in this shift, Chemistry question 10 of 30, Section A.

The oxidation states of Fe in

\mathrm{[Fe(NCS)(NH_3)_5]SO_4}

\mathrm{Na_3[Fe(S_2O_3)_3]}

and

\mathrm{[Fe(CO)_5]}

respectively are

(1)3, 2 and 1
(2)3, 3 and 0Official answer
(3)2, 3 and $-2$
(4)3, 3 and $-2$

Official answer

Option 2

NTA final key.

Chapter: Coordination Compounds
Topic: Coordination Nomenclature
Idea tested: Oxidation State Calculation

Same idea in other shifts

Asked 7× in all

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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.