. What is meant by the chelate effect Give an example

Best Answer


  • The complex formed by a polydentate ligand with a metal ion is more stable than the complex formed by the same metal and with the monodentate ligands. The greater stability of polydentate ligands is called the chelate effect. 
  • The greater stability of the polydentate complex is due to the entropy factor because  a polydentate can replace many mono-dentate ligands and entropy of reaction increases.
  • Example- [Fe (EDATA) ]- (Ethylenediaminetetraacetatoferrate(III) ion) is more stable than a mono dentate [Fe(H2O)6 ]2+ ,Hexaaquairon (II)  complex

             polydentate complex

Final Answer:

A polydentate ligand is more stable than the monodentate ligand with the same metal ion and this is called  chelate effect

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