CBSE Class 12-science Answered
Compounds which gives different ions in solution although they have same composition are called ionisation isomerism.
This form of isomerism arises when the counter ion in a complex salt is itself a potential ligand and can displace a ligand which can then become the counter ion.
An example is provided by the ionisation isomers [Co(NH3)4Br2]Cl and [Co(NH3)4BrCl]Br.
[Co(NH3)4Br2]Cl [Co(NH3)4Br2]+ + Cl-
[Co(NH3)4BrCl]Br [Co(NH3)4BrCl]+ + Br-
As given complex is octahedral it will also show the geometrical isomerism as follows: