JEE Main 2024 · ChemistryMultiple choiceSingle correctMediumApplication

JEE Main 4 April 2024, Shift 1, Chemistry Q71

Question 71 of 90 in this shift, Chemistry question 11 of 30, Section A.

Number of complexes from the following with even number of unpaired "d" electrons is ________.

[\mathrm{V(H_2O)_6}]^{3+}

[\mathrm{Cr(H_2O)_6}]^{2+}

[\mathrm{Fe(H_2O)_6}]^{3+}

[\mathrm{Ni(H_2O)_6}]^{3+}

[\mathrm{Cu(H_2O)_6}]^{2+}

[Given atomic numbers : V = 23, Cr = 24, Fe = 26, Ni = 28 Cu = 29]

(1)1
(2)2Official answer
(3)4
(4)5

Official answer

Option 2

NTA final key.

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

Same idea in other shifts

Asked 34× in all

4 Apr 2026, Shift 2 · Q60Consider the metal complexes $\mathrm{[Ni(en)_3]^{2+}}$ (A), $\mathrm{[NiCl_4]^{2-}}$ (B) and $\mathrm{[Ni(NH_3)_6]^{2+}}$ (C). Choose the…MediumSingle correct
5 Apr 2026, Shift 2 · Q71The total number of unpaired electrons present in the $d^3$ , $d^4$ (low spin) $d^5$ (high spin), $d^6$ (high spin) and $d^7$ (low spin)…EasyNumerical value
6 Apr 2026, Shift 2 · Q61Which of the following sequences of hybridisation, geometry and magnetic nature are correct for the given coordination compounds ? A.…MediumOther
8 Apr 2026, Shift 2 · Q71Number of paramagnetic complexes among the following is ________. $[\mathrm{MnBr_4}]^{2-}$ , $[\mathrm{NiCl_4}]^{2-}$ ,…MediumNumerical value
2 Apr 2025, Shift 1 · Q60Given below are two statements : Statement (I) : In octahedral complexes, when $\Delta_o<$ P high spin complexes are formed. When…EasyTwo statements
2 Apr 2025, Shift 1 · Q74A transition metal (M) among Mn, Cr, Co and Fe has the highest standard electrode potential ( $\mathrm{M^{3+}/M^{2+}}$ ). It forms a metal…MediumNumerical value
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 108 of the 174 JEE Main shifts held from 2017 to 2026.