Question

The coordination complex CoNO₂Cl.5NH₃ exist in two isomeric forms ‘P’ and ‘Q’. Isomer ‘P’ reacts with AgNO₃ solution to give white precipitate whereas ‘Q’ does not give any precipitate with AgNO₃ solution.

1. Write the structural formula of isomers ‘P’ and ‘Q’.
2. Name the type of isomerism involved.

Answer 1

(1) Isomer ‘P’: [Co(NH₃)5(NO₂)]Cl 

Isomer ‘Q’: [Co(NH₃)5Cl]NO₂ 

(2) The type of isomerism involved is Ionisation Isomerism. This occurs when compounds with the same molecular formula produce different ions in solution because an ion that can act as a ligand exchanges places with an ion outside the coordination sphere.