When copper (ii) sulphate solution is treated with excess ammonium hydroxide, a precipitate is first formed, and then this dissolves to give a deep blue solution.
This deep blue solution is a?
- Cu(OH)2
- CuSo4.5H2O
- (NH4)2SO4
-
Cu(NH3)4(OH)2
- CuSO4.(NH4)2SO4.2H2O
The correct answer is: D
Explanation
\(CuSO_4+2NH_4OH→(NH_4)_2SO_4+Cu(OH)_2\)(pale−blue)
The pale blue precipitate of copper hydroxide dissolves in excess of ammonium hydroxide forming tetraamine copper [II] sulphate, an azure blue(deep blue) soluble complex salt.
\(Cu(OH)_2+(NH_4)_2SO_4+2NH_4OH→[Cu(NH_3)_4]SO_4+4H_2O\)