JEE Main 2020 · ChemistryMultiple choiceOtherMediumMulti-step

JEE Main 9 January 2020, Shift 2, Chemistry Q37

Question 37 of 75 in this shift, Chemistry question 12 of 25, Section A.

The correct order of the spin-only magnetic moments of the following complexes is : (I)

\mathrm{[Cr(H_2O)_6]Br_2}

(II)

\mathrm{Na_4[Fe(CN)_6]}

(III)

\mathrm{Na_3[Fe(C_2O_4)_3]}

(

\Delta_0 > P

) (IV)

\mathrm{(Et_4N)_2[CoCl_4]}

(1)(III) > (I) > (IV) > (II)
(2)(I) > (IV) > (III) > (II)Official answer
(3)(II) $\approx$ (I) > (IV) > (III)
(4)(III) > (I) > (II) > (IV)

Official answer

Option 2

NTA final key (Jan 2020).

Chapter: Coordination Compounds
Topic: Crystal Field Theory
Idea tested: High and Low Spin States

Same idea in other shifts

Asked 19× in all

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2 Apr 2025, Shift 2 · Q61The type of hybridization and the magnetic property of $\mathrm{[MnCl_6]^{3-}}$ are,MediumSingle correct
3 Apr 2025, Shift 2 · Q62Identify the diamagnetic octahedral complex ions from below ; A. $[\mathrm{Mn(CN)_6}]^{3-}$ B. $[\mathrm{Co(NH_3)_6}]^{3+}$ C.…MediumOther

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 42 of the 174 JEE Main shifts held from 2017 to 2026.