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Indian Forest Service (Mains)

Chemistry optional

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

Paper I covers physical and inorganic chemistry.

Indian Forest Service (Mains), Chemistry optional · 2016 · Paper I

Q5(b)(i). Chelate effect

Question

Explain the following terms: (i) Chelate effect

Answer in brief

A complex with a chelating (polydentate) ligand is much more stable than one with the same number of comparable monodentate donor atoms: [Ni(en)₃]²⁺, log β₃=18.3, against [Ni(NH₃)₆]²⁺, log β₆=8.6. The gain is mainly entropic.

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Topic notes: labile and inert complexes, substitution mechanisms, the trans effect, stability constants and the chelate effect, with every Civil Services, IFoS and Geo-Scientist PYQ →

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