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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 · 2023 · Mains Paper I

Q3(a). Normal and inverse spinels

Question

Give an example for spinel solid and explain the charge distribution of AB₂O₄ system. Mention the structural changes in the case of inverse spinel.

Answer in brief

Normal spinel: (A²⁺)tet[B³⁺₂]oct O₄. Inverse spinel: (B³⁺)tet[A²⁺B³⁺]oct O₄.

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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.

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Topic notes: inorganic solids: perovskite, spinel, ReO₃, corundum, high-Tc superconductors and solid-state synthesis, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversnormal spinelinverse spinelAB2O4magnetite Fe3O4MgAl2O4ferrites

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