Question

A white crystalline substance dissolves in water. On passing `H_(2)S` in this solution, a black precipitate is obtained. The black drops of conc. `H_(2)SO_(4)` a white precipitate is obtained. This precipitate is that of
A. `BaSO_(4)`
B. `SrSO_(4)`
C. `PbSO_(4)`
D. `CdSO_(4)`

Answer 1

Correct Answer - C
`Pb^(+2)+H_(2)S underset(acidic)tounderset(("black ppt."))(PbS)darr+H_(2)uarr`
`3PbS+8HNO_(3)to3Pb(NO_(3))_(2)+2NO+3S+4H_(2)O`
`Pb(NO_(3))_(2)+H_(2)SO_(4)to underset(("white ppt."))(PbSO_(4))darr+2HNO_(3)uarr`