In qualitative analysis when `H_(2)S` is passed through an aqueous solution of salt acidified with dil. HCl, a black precipitate is obtained. On boiling the precipitate with dil. `HNO_(3)`, it forms a solution of blue colour. Addition of excess of aqueous solution of ammonia to this solution gives

Options

A. deep blue precipitate of `Cu(OH)_(2)`
B. deep blue solution of `[Cu (NH_(3))_(4)]^(2+)`
C. deep blue solution of `Cu(NO_(3))_(2)`
D. deep blue solution of `Cu(OH)_(2). Cu (NO_(3))_(2)`

Answer

B

Explanation

It is the correct answer.