A blue solution of copper sulphate becomes darker when treated with excess of ammonia. This is because

Options

A. ammonia molecules replace water molecules in the solution
B. ammonia is stronger ligand than water
C. ammonia froms a stable comlex ion `[Cu(NH_(3)_(4)]^(2+)`with `Cu^(2+)` ions
D. All of above

Answer

D

Explanation

`underset("Blue")([Cu(H_(2)O)_(4)]^(2+))+SO_(4)^(2-)+4NH_(3)rarr[Cu(NH_(3))_(4)]^(2+)+4H_(2)O`
`NH_(3)` being a stronger ligand than `H_(2)O`, replaces `H_(2)O` and forms stable deep-blue coloured complex with `Cu^(2+)`.