9.13 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.
Aqueous copper sulphate solution is blue due to the formation of [Cu(H2O)4]SO4
[Cu(H2O)4]SO4(aq) ⇌ [Cu(H2O)4]2++SO2−4
[Cu(H2O)4]2+ is a labile complex in which ligands H2O get easily replaced by F− ion of KF (as in (i) part) and by Cl− ion of KCl (as in (ii) part).
(i). [Cu(H2O)4]2+(aq)+4F−(aq)→[CuF4]2− Green ppt. + 4H2O
(ii).[Cu(H2O)4]2+(aq)+4Cl−(aq)→[CuCl4]2−(aq) (Bright green solution) + 4H2O
In both these cases, the weak field ligand water is replaced by the F− and Cl− ions.
© 2024 GoodEd Technologies Pvt. Ltd.
