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........ .

In qualitative analysis when H_(2)S is passed through an aqueous solut

1.	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........ .
Answer» deep blue precipitate of `Cu(OH)_(2)` deep blue solution of `[Cu(NH_(3))_(4)]^(2+)` deep blue solution of `Cu(NO_(3))_(2)` deep blue solution of `Cu(OH)_(2).Cu(NO_(3))_(2)` Solution :`underset("Salt")(CuSO_(4))+H_(2)S OVERSET("Dil.HCI")rarr underset(("Black ppt."))(CuS)+H_(2)SO_(4)" ,"" "CuS + 2HNO_(3) rarr underset(("Blue solution"))(Cu(NO_(3))_(2))+H_(2)S` `Cu(NO_(3))_(2) + 4NH_(3) rarr underset(("Deep blue solution"))([Cu(NH_(3))_(4)]^(2+)) + 2NO_(3)^(-)`