An aqueous solution of a mixture of two inorganic salts, when treated with dilute HCI, gave a precipitate (P) and a filtrate (Q). The precipitate (P) was found to dissolved in hot water. The filtrate (Q) remained unchanged, when treated with `H_(2)S` in a dilute mineral acid medium. However, it gave a precipitatew (R) with `H_(2)S` in an ammoniacal medium. The precipitate (R) gave a coloured solution (S), when treated with `H_(2)O_(2)` in an aqueous NaOH medium. The precipitate (P) contains ------ while the colored solution (S) contains

Options

A. `Pb^(2+)` , `Na_(2)CrO_(4)`
B. `Hg_(2)^(2+)` , `CuSO_(4)`
C. `Hg^(2+)` , `ZnSO_(4)`
D. `Ag^(+)` , `Fe_(2)(SO_(4))_(3)`

Answer

A

Explanation

`Pb^(2+)+2HCl toPbCl_(2)darroverset(Hot)underset(Water)(to)"soluble"`
`Cr^(3+)underset("ammoniacal")overset(H_(2)S)toCr(OH_(3))darr`
`Cr(OH)_(3)overset(NaOH)underset(H_(2)O_(2))tounderset("Yellow solution") (Na_(2)CrO_(4))`