In qualitative analysis when H_(2)S is passed through an aqueous solution ofsalt acidified with dil. HCL, a block precipitate is obtainned .On boiling the precipitate with dil. HNO_(3) it forms a solution of blue colour . Addition of excess ofaqueous solution of ammonia to this solution given ....... .

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 ofsalt acidified with dil. HCL, a block precipitate is obtainned .On boiling the precipitate with dil. HNO_(3) it forms a solution of blue colour . Addition of excess ofaqueous solution of ammonia to this solution given ....... .
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 `(ON_(3))_(2)` Solution :In qualitative analysis when `H_(2)S` is PASSED through an aqueous sloution of salt acidified with DIL . HCl a black ppt. of CuS is obtained . `CuSO_(4)+H_(2)Soverset(dil. HCl)tounderset("blackppt")( CuS +)H_(2)SO_(4)` On boiling CuS with dil. `HNO_(3)` it FORMS a blue coloured solution and the following reactions OCCUR `3CuS+8HNO_(3)to3Cu(NO_(3))_(2)+2NO+3S+4H_(2)O` `S+2HNO_(3)toH_(2)SO_(4)+NO` `2Cu^(2+)+SO_(4)^(2-)+2NH_(3)+2H_(2)OtoCu(OH)_(2)CuSO_(4)+2NH_(4)OH` `Cu(OH)_(2)CuSO_(4)+8NH_(3)tounderset("Tetraammine copper"(\|\|)("Deep blue solution"))(2[Cu(NH_(3))_(4)]SO_(4)+2OH^(-)+SO_(4)^(2-)`