Saved Bookmarks
| 1. |
Aqueous copper sulphate solution (blue in colour) gives : (i) a green precipitate with aqueous potassium fluoride and (ii) a bright green solution with aqueous potassium chloride. Explain these experimental results. |
|
Answer» Solution :Aqueous `CuSO_(4)` solution EXISTS as `[Cu(H_(2)O)_(4)]SO_(4)` which has blue colour. (i) When KF is added, weak `H_(2)O` ligands are replaced by F ligands forming `[CuF_(4)]^(2-)` ions which is a green precipitate. `[Cu(H_(2)O)_(4)]^(2+)+4F^(-)tounderset("Tetrafluorocuprate(II)(Green ppt.)")([CuF_(4)]^(2-))+4H_(2)O` (ii) When KCl is added, weak `H_(2)O` ligands are replaced by `CL^(-)` ligands forming `[CuCl_(4)]^(2-)` ion which has bright green colour. `[Cu(H_(2)O)_(4)]^(2+)+4Cl^(-)tounderset("Tetrachlorocuprate(II)(Bright Green solution)")([CuCl_(4)]^(2-))+4H_(2)O` |
|