JEE Main 2021 · ChemistryMultiple choiceSingle correctMediumApplication

JEE Main 22 July 2021, Shift 2, Chemistry Q40

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

The set having ions which are coloured and paramagnetic both is :

(1) $\mathrm{Cu^{2+}, Cr^{3+}, Sc^{+}}$ Official answer
(2) $\mathrm{Cu^{+}, Zn^{2+}, Mn^{4+}}$
(3) $\mathrm{Sc^{3+}, V^{5+}, Ti^{4+}}$
(4) $\mathrm{Ni^{2+}, Mn^{7+}, Hg^{2+}}$

Official answer

Option 1

NTA final key.

Chapter: The d- and f-Block Elements
Topic: d-Block Elements
Idea tested: Spin-only Magnetism

Same idea in other shifts

Asked 23× in all

2 Apr 2026, Shift 2 · Q74Number of paramagnetic ions among the following d- and f-block metal ions is __________.…MediumNumerical value
4 Apr 2026, Shift 2 · Q62Consider $|x|$ is the difference in oxidation states of Mn in highest manganese fluoride and highest manganese oxide. The ions with $|x|$ …MediumOther
3 Apr 2025, Shift 1 · Q62The metal ions that have the calculated spin-only magnetic moment value of 4.9 B.M. are : A. $\mathrm{Cr^{2+}}$ B. $\mathrm{Fe^{2+}}$ C.…EasyOther
8 Apr 2025, Shift 2 · Q58The correct decreasing order of spin only magnetic moment values (BM) of $\mathrm{Cu^+}$ , $\mathrm{Cu^{2+}}$ , $\mathrm{Cr^{2+}}$ and…EasySingle correct
4 Apr 2024, Shift 2 · Q69A first row transition metal in its +2 oxidation state has a spin-only magnetic moment value of 3.86 BM. The atomic number of the metal isEasySingle correct
5 Apr 2024, Shift 1 · Q86The spin-only magnetic moment value of the ion among $\mathrm{Ti^{2+}}$ , $\mathrm{V^{2+}}$ , $\mathrm{Co^{3+}}$ and $\mathrm{Cr^{2+}}$ ,…MediumNumerical value
5 Apr 2024, Shift 1 · Q87In a borax bead test under hot condition, a metal salt (one from the given) is heated at point B of the flame, resulted in green colour…HardNumerical valueHas a figure
6 Apr 2024, Shift 1 · Q86Among CrO, $\mathrm{Cr_2O_3}$ and $\mathrm{CrO_3}$ , the sum of spin-only magnetic moment values of basic and amphoteric oxides is ________…MediumNumerical value

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.