Statement-1:When `H_(2)S` gas is passed into an aqueous solution of `ZnCl_(2),Zn^(2+)` ions are completely precipitated as zinc sulphide.
Statement-2 :Zinc sulphide is soluble in solutions of caustic alkali as well as in dilute `HCl`.

Options

A. STATEMENT-1 is true, STATEMENT-2 is true and STATEMENT-2 is correct explanation for STATEMENT-1
B. STATEMENT-1 is true, STATEMENT-2 is true and STATEMENT-2 is not correct explanation for STATEMENT-2
C. STATEMENT-1 is true, STATEMENT-2 is false
D. STATEMENT-1 is false, STATEMENT-2 is true

Answer

E

Explanation

Statement-1 :`Zn^(2+) +H_(2)S hArrZnS+2H^(+) , H_(2)S hArr 2H^(+) +S^(2-)`
Sulphide ion concentration obtained from the `H_(2)S` is depressed so much by the hydrogen-ion concentration from acid that it is too low to exceed the solubility product of `ZnS` and consequenctly precipitation ceases.
Statement-2 :`ZnS` is insoluble in caustic alkali solution, but dissolves according to the following reaction in dilute `HCl`
`ZnS + 2HCl to ZnCl_(2)+H_(2)S`.