A coordination compound with the empirical formula Co ( NH ₃ )₅ BrSO ₄ exists in two isomeric forms, A and B. When an aqueous solution of form A is treated with BaCl ₂ solution, a white precipitate is formed. When an aqueous solution of form B is treated with AgNO ₃ solution, a pale yellow precipitate is formed. The type of structural isomerism exhibited by forms A and B is:

Step-by-step solution

The formation of a white precipitate with BaCl ₂ indicates the presence of free sulphate ions ( SO ₄²⁻ ) in the solution. This means form A has sulphate outside the coordination sphere: [ Co ( NH ₃ )₅ Br ] SO ₄ . The formation of a pale yellow precipitate with AgNO ₃ indicates the presence of free bromide ions ( Br ^- ) in the solution. This means form B has bromide outside the coordination sphere: [ Co ( NH ₃ )₅ SO ₄ ] Br . Since forms A and B differ in the distribution of ions between the coordination sphere and