JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyCalculation

JEE Main 25 July 2021, Shift 2, Chemistry Q39

Question 39 of 90 in this shift, Chemistry question 9 of 30, Section A.

The spin only magnetic moments (in BM) for free

\mathrm{Ti^{3+}}

\mathrm{V^{2+}}

and

\mathrm{Sc^{3+}}

ions respectively are (At. No. Sc : 21 ; Ti : 22 ; V : 23)

(1)0, 3.87, 1.73
(2)1.73, 0, 3.87
(3)3.87, 1.73, 0
(4)1.73, 3.87, 0Official answer

Official answer

Option 4

NTA final key.

Chapter: The d- and f-Block Elements
Topic: Crystal Field Theory
Idea tested: Spin-only Magnetic Moment

Same idea in other shifts

Asked 28× in all

4 Apr 2026, Shift 1 · Q62Match the LIST-I with LIST-II List-I (Complex ion): A. $[\mathrm{Cr(H_2O)_6}]^{2+}$ ; B. $[\mathrm{Co(H_2O)_6}]^{2+}$ ; C.…EasyMatch the list
8 Apr 2025, Shift 2 · Q60Match the LIST-I with LIST-II LIST-I (Complex/ Species) | LIST-II (Shape & magnetic moment) A. $\mathrm{[Ni(CO)_4]}$ | I. Tetrahedral, 2.8…MediumMatch the list
5 Apr 2024, Shift 1 · Q71Which one of the following complexes will exhibit the least paramagnetic behaviour ? [Atomic number, Cr = 24, Mn = 25, Fe = 26, Co = 27]EasySingle correct
8 Apr 2024, Shift 2 · Q70Match List - I with List - II. List - I (Complex ion) | List - II (Spin only magnetic moment in B.M.) (A) $[\mathrm{Cr(NH_3)_6}]^{3+}$ |…MediumMatch the list
27 Jan 2024, Shift 1 · Q69Consider the following complex ions $\mathrm{P=[FeF_6]^{3-}}$ $\mathrm{Q=[V(H_2O)_6]^{2+}}$ $\mathrm{R=[Fe(H_2O)_6]^{2+}}$ The correct…MediumSingle correct
31 Jan 2024, Shift 1 · Q86The 'Spin only' Magnetic moment for $[\mathrm{Ni(NH_3)_6}]^{2+}$ is _________ $\times10^{-1}$ BM. (given = Atomic number of Ni : 28)EasyNumerical value
31 Jan 2024, Shift 2 · Q70Select the option with correct property -MediumSingle correct
6 Apr 2023, Shift 1 · Q72Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: The spin only magnetic…MediumAssertion–reason

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.