VKC ScienceChemistry for written exams Telegram

UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper I covers inorganic chemistry.

UPSC Combined Geo-Scientist, Mains · 2018 · Mains Paper I

Q11(a). Ce and Yb magnetic moments

Question

Calculate the magnetic moment of Ce³⁺ (f¹) and Yb³⁺ (f¹³) considering spin-orbit coupling. Comment on the difference (if any) in the ground State terms and values of the moment, of the two ions.

Answer in brief

Ce(III): ²F_(5/2), μ=2.54μ_B; Yb(III): ²F_(7/2), μ=4.54μ_B.

Part of VKC Basic

Read the key points and the full model answer with VKC Basic

VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.

See what is included Already a member? Sign in

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

The handwritten model answer pages open with the VKC plan.
Read the whole 2018 solution2018 question paper

CoversYb magnetic momentsSpin–orbit coupling in lanthanides

All parts of Question 11