Question

Give a chemical test to show that \[\ce{[Co(NH3)5Cl]SO4}\] and \[\ce{[Co(NH3)5SO4]CI}\] are ionisation isomers.

Answer 1

\[\ce{[Co(NH3)5Cl]SO4}\] produces a white precipitate when mixed with BaCl₂. This test yields no response from \[\ce{[Co(NH3)5SO4]Cl}\]. In contrast, \[\ce{[Co(NH3)5SO4]Cl}\] produces a white precipitate in the presence of silver nitrate, whereas \[\ce{[Co(NH3)5Cl]SO4}\] does not. These results demonstrate that \[\ce{[Co(NH3)5Cl] SO4}\] and \[\ce{[Co(NH3)5SO4]Cl}\] are ionisation isomers.

1. \[\ce{[Co(NH3)5Cl]SO4 <=> [Co(NH3)5Cl]^2- + SO^2-_4 ↓ BaCl2 \underset{White ppt.}{BaSO4}}\]
   However, it does not react with AgNO₃
2. \[\ce{[Co(NH3)5Cl]SO4 ->[AgNO3] No reaction}\]
3. \[\ce{[Co(NH3)5SO4]Cl <=> [Co(NH3)5SO4]+ +Cl- ->[AgNO3] \underset{White ppt.}{AgCl}}\]
   But it does not react with the BaCl₂ solution
4. \[\ce{Co(NH3)5SO4]Cl ->[BaCl2] No reaction}\]