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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 · 2022 · Mains Paper I

Q4(a). VBT for tetrahedral nickel complexes

Question

How does the VBT account for the following facts? (i) [NiCl₄]²⁻ is paramagnetic and tetrahedral. (ii) [Ni(CO)₄] is diamagnetic and tetrahedral.

Answer in brief

Both use four sp³ acceptor hybrids in the traditional VBT picture. Ni(II)-chloride has two unpaired 3d electrons; Ni(0)-carbonyl has a paired 3d¹⁰ configuration.

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Topic notes: Werner theory, isomerism, IUPAC names and valence bond theory of complexes, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversvalence bond theorysp3 hybridisation[NiCl4]2- paramagneticNi(CO)4 diamagnetictetrahedral complexes

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