Give the evidence that `[Co(NH_(3))_(5)Cl]SO_(4)and[Co(NH_(3))_(5)SO_(4)]Cl` are ionisation isomers.

Explanation

We dissolve both the compounds in water with different test tubes. To the both test tubes,
Case I Add `BaCl_(2)` solution, one compound give white ppt. indicating the presence of `SO_(4)^(2-)` ions.
The other compound does not give white precipitate, indicating the absence og `S_(4)^(2-)` ions.
`[Co(NH_(3))_(5)Cl]SO_(4)+BaCl_(2)("aq")rarr[Co(NH_(3))_(5)Cl]Cl_(2)+underset("White ppt.")(BaSO_(4)(s))`
`[Co(NH_(3))_(5)SO_(4)]Cl+BaCl_(2)("aq")rarr"No reaction"`
Case II Add `AgNO_(3)` solution to both the compounds in separate test tubes. Only II compound gives white precipitate, not the I, due to the absence of `Cl^(-)` as counter ion.
`[Co(NH_(3))_(5)SO_(4)]Cl+AgNO_(3)("aq")rarr[CO(NH_(3))_(5)SO_(4)]NH_(3)+underset("White ppt.")(AgCl(s))`
`[Co(NH_(3))_(5)Cl]SO_(4)+AgNO_(3)("aq")rarr"No reaction"`
These two test prove that the given two compounds are a pair of ionisation isomers.