Indian Forest Service (Mains), Chemistry optional · 2021 · Paper I
Q8(c). Magnetic moments of Eu(III) and Sm(III)
Question
Deduce the effective magnetic moment (μ_eff) for (i) Europium (Eu³⁺) (ii) Samarium (Sm³⁺). Given: μ_eff = g√[J(J + 1)], g = 3/2 + [S(S + 1) − L(L + 1)]/[2J(J + 1)].
Model answer
The free solution for 2021 answers questions 1, 2, 4, 5 and 6, the ones picked in its time plan. Question 8 is answered in full in the IFoS Chemistry Paper I, 2021 to 2025 book, with every part of every paper.
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UPSC Indian Forest Service (Main) Chemistry Paper I: Model Answers 2021 to 2025
- All eight questions of each paper, with the question printed above its answer
- Physical chemistry numericals worked with units; inorganic structures drawn
- Topic-wise weightage and a topic-wise index
Coversmagnetic moment of lanthanidesLandé g factorEu³⁺Sm³⁺spin–orbit coupling
All parts of Question 8
- 8(a) Structures from coordination names15 marks
- 8(b) Magnesium in glycolysis15 marks
- 8(c) Magnetic moments of Eu(III) and Sm(III)10 marks