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Saturday, 31 October

JEE Main · Chemistry · Coordination Compounds

Spin-only Magnetic Moment

JEE Main asked Spin-only Magnetic Moment 28 times in 27 of the 108 shifts Lumi analysed, in 2020, 2021, 2022, 2023, 2024, 2025 and 2026. It belongs to Crystal Field Theory, in Coordination Compounds (Chemistry). The longest wait between two years asking it was 1 year. In 2020, 2021, 2022, 2023 and 2024 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
28
in 27 shifts
Years
7 of 8
First asked
2020
last in 2026
Pattern
Asked most years
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.30.60’170.17’200.14’210.28’220.49’230.23’240.13’250.11’26

Raw count: 2017: 0 in 1 shift · 2020: 2 in 12 shifts · 2021: 4 in 24 shifts · 2022: 8 in 24 shifts · 2023: 7 in 12 shifts · 2024: 5 in 18 shifts · 2025: 1 in 8 shifts · 2026: 1 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20261 of 9
  • 20251 of 8
  • 20245 of 18
  • 202326 of 12
  • 20228 of 24
  • 20214 of 24
  • 20202 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: calculation.

  • Spin-only magnetic moment of complex
  • Order/ranking of spin-only magnetic moments

Difficulty

Easy 8Medium 18Hard 2

9 of the 28 questions had a numerical answer.

Every question

All 28 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 4 Apr 2026, Shift 1 · Q62Match the LIST-I with LIST-II List-I (Complex ion): A. [Cr(H2O)6]2+[\mathrm{Cr(H_2O)_6}]^{2+}; B. [Co(H2O)6]2+[\mathrm{Co(H_2O)_6}]^{2+}; C.…EasyMatch the list
  2. 8 Apr 2025, Shift 2 · Q60Match the LIST-I with LIST-II LIST-I (Complex/ Species) | LIST-II (Shape & magnetic moment) A. [Ni(CO)4]\mathrm{[Ni(CO)_4]} | I. Tetrahedral, 2.8…MediumMatch the list
  3. 31 Jan 2024, Shift 2 · Q70Select the option with correct property -MediumSingle correct
  4. 31 Jan 2024, Shift 1 · Q86The 'Spin only' Magnetic moment for [Ni(NH3)6]2+[\mathrm{Ni(NH_3)_6}]^{2+} is _________ ×10−1\times10^{-1} BM. (given = Atomic number of Ni : 28)EasyNumerical value
  5. 27 Jan 2024, Shift 1 · Q69Consider the following complex ions P=[FeF6]3−\mathrm{P=[FeF_6]^{3-}} Q=[V(H2O)6]2+\mathrm{Q=[V(H_2O)_6]^{2+}} R=[Fe(H2O)6]2+\mathrm{R=[Fe(H_2O)_6]^{2+}} The correct…MediumSingle correct
  6. 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) [Cr(NH3)6]3+[\mathrm{Cr(NH_3)_6}]^{3+} |…MediumMatch the list
  7. 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. 13 Apr 2023, Shift 2 · Q70Which of the following complexes will exhibit maximum attraction to an applied magnetic field?EasySingle correct
  9. 11 Apr 2023, Shift 2 · Q69The magnetic moment is measured in Bohr Magneton (BM). Spin only magnetic moment of Fe in [Fe(H2O)6]3+\mathrm{[Fe(H_2O)_6]^{3+}} and…EasySingle correct
  10. 11 Apr 2023, Shift 1 · Q88The ratio of spin-only magnetic moment values…EasyNumerical value
  11. 8 Apr 2023, Shift 2 · Q69Match List I with List II LIST I (Coordination Complex): A. [Cr(CN)6]3−[\mathrm{Cr(CN)_6}]^{3-}; B. [Fe(H2O)6]2+[\mathrm{Fe(H_2O)_6}]^{2+}; C.…MediumMatch the list
  12. 8 Apr 2023, Shift 2 · Q90The observed magnetic moment of the complex [Mn(NCS)6]x−[\mathrm{Mn(NCS)_6}]^{x-} is 6.06 BM. The numerical value of xx is ____________.MediumNumerical value
  13. 8 Apr 2023, Shift 1 · Q72The correct order of spin only magnetic moments for the following complex ions isMediumSingle correct
  14. 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
  15. 30 Jun 2022, Shift 1 · Q87Spin only magnetic moment (μs\mu_s) of K3[Fe(CN)6]\mathrm{K_3[Fe(CN)_6]} is ___________ B.M. (Nearest integer).MediumNumerical value
  16. 29 Jun 2022, Shift 2 · Q86Spin only magnetic moment of [MnBr6]4−[\mathrm{MnBr_6}]^{4-} is ___ B.M. (round off to the closest integer)MediumNumerical value
  17. 27 Jun 2022, Shift 2 · Q70Arrange the following coordination compounds in the increasing order of magnetic moments. (Atomic numbers: Mn = 25; Fe = 26) A.…MediumOther
  18. 26 Jun 2022, Shift 1 · Q87The spin-only magnetic moment value of an octahedral complex among CoCl3⋅4NH3\mathrm{CoCl_3\cdot4NH_3}, NiCl2⋅6H2O\mathrm{NiCl_2\cdot6H_2O} and…HardNumerical value
  19. 25 Jun 2022, Shift 2 · Q87Amongst FeCl3.3H2O\mathrm{FeCl_3.3H_2O}, K3[Fe(CN)6]\mathrm{K_3[Fe(CN)_6]} and [Co(NH3)6]Cl3\mathrm{[Co(NH_3)_6]Cl_3}, the spin-only magnetic moment value of the…HardNumerical value
  20. 27 Jul 2022, Shift 2 · Q89The spin only magnetic moment of the complex present in Fehling’s reagent is __________ B.M. (Nearest integer).MediumNumerical value
  21. 26 Jul 2022, Shift 2 · Q71The metal complex that is diamagnetic is (Atomic number: Fe,26; Cu,29)MediumSingle correct
  22. 26 Jul 2022, Shift 1 · Q89The difference between spin only magnetic moment values of [Co(H2O)6]Cl2[\mathrm{Co(H_2O)_6}]\mathrm{Cl_2} and [Cr(H2O)6]Cl3[\mathrm{Cr(H_2O)_6}]\mathrm{Cl_3}…EasyNumerical value
  23. 25 Jul 2021, Shift 2 · Q39The spin only magnetic moments (in BM) for free Ti3+\mathrm{Ti^{3+}}, V2+\mathrm{V^{2+}} and Sc3+\mathrm{Sc^{3+}} ions respectively are (At.…EasySingle correct
  24. 25 Feb 2021, Shift 2 · Q39In which of the following order the given complex ions are arranged correctly with respect to their decreasing spin only magnetic moment ?…MediumSingle correct
  25. 24 Feb 2021, Shift 2 · Q40The calculated magnetic moments (spin only value) for species [FeCl4]2−\mathrm{[FeCl_4]^{2-}}, [Co(C2O4)3]3−\mathrm{[Co(C_2O_4)_3]^{3-}} and…MediumSingle correct
  26. 31 Aug 2021, Shift 2 · Q39Spin only magnetic moment in BM of [Fe(CO)4(C2O4)]+[\mathrm{Fe(CO)_4(C_2O_4)}]^+ is :MediumSingle correct
  27. 4 Sep 2020, Shift 1 · Q38The pair in which both the species have the same magnetic moment (spin only) is :MediumSingle correct
  28. 8 Jan 2020, Shift 2 · Q37The correct order of the calculated spin-only magnetic moments of complexes (A) to (D) is : (A) Ni(CO)4\mathrm{Ni(CO)_4} (B)…MediumSingle correct

Shifts: 8 Jan 2020, Shift 2, 4 Sep 2020, Shift 1, 24 Feb 2021, Shift 2, 25 Feb 2021, Shift 2, 25 Jul 2021, Shift 2, 31 Aug 2021, Shift 2, 25 Jun 2022, Shift 2, 26 Jun 2022, Shift 1, 27 Jun 2022, Shift 2, 29 Jun 2022, Shift 2, 30 Jun 2022, Shift 1, 26 Jul 2022, Shift 2, 26 Jul 2022, Shift 1, 27 Jul 2022, Shift 2, 6 Apr 2023, Shift 1, 8 Apr 2023, Shift 2, 8 Apr 2023, Shift 1, 11 Apr 2023, Shift 2, 11 Apr 2023, Shift 1, 13 Apr 2023, Shift 2, 27 Jan 2024, Shift 1, 31 Jan 2024, Shift 2, 31 Jan 2024, Shift 1, 5 Apr 2024, Shift 1, 8 Apr 2024, Shift 2, 8 Apr 2025, Shift 2, 4 Apr 2026, Shift 1.

Same topic

Other ideas in Crystal Field Theory

Crystal Field Theory has 15 ideas JEE Main has asked; 8 of them came up in more than one question. The 12 most asked are below.

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