A metal sulphide A gives gas B with rotten egg smell and a colourless sulphate C, when treated with dil `H_2SO_4`. B reacts with `K_2Cr_2O_7//H^+` to form D, a white grey element. D burns in oxygen to yield E a colourless gas. If B is added to E, it gives D and a colourless liquid, which turns anhydrous `CuSO_4` blue. C gives precipitate with `NH_(3(aq))` or NaOH, which dissolves in excess of NaOH

Options

A. `CuSO_4`
B. `BaSO_4`
C. `ZnSO_4`
D. `Na_(2)ZnO_2`

Answer

C

Explanation

`underset((A))(Zns )+ H_2SO_4 rarr underset((B))(H_2S) + underset((C))(ZnSO_4)`
`H_2S + K_2Cr_2O_7 rarr underset((D))(S+Cr_2O_3)`
`S+O_2 rarr underset((E)) SO_2`
`H_2S + SO_2 rarr S + H_2O`
`CuSO_4 + H_2O rarr underset((Blue))(CuSO_4.) 5H_2O`
`ZnSO_4 + NaOH rarr underset((white))(Zn(OH)_2darr) overset(NaOH) rarr underset("(soluble)")(Na_2ZnO_2)`