An aqueous solution of a mixture of two inorganic salts when treated with dilute HCl, gave a precipitate (P) and a filtrate (Q). The precipitate (P) was found to dissolve in hot water. The filtrate (Q) remained unchanged, when treated with `H_(2)S` in a dilute mineral acid medium. However, it gave a green precipitate (R) in an ammoniacal medical. The precipitate (R) gave a coloured solution (S), when treated with `H_(2)O_(2)` in an aqueous NaOH medium. Answer Question 62 and 63
The coloured solution (S) contains

Options

A. `Fe(SO_(4))_(3)`
B. `CuSO_(4)`
C. `ZnSO_(4)`
D. `Na_(2)CrO_(4)`

Answer

D

Explanation

The coloured solution (S) is `Na_(2)CrO_(4)`
The available data suggests that the mixture contains `Pb^(2+)` and `Cr^(3+)` ions. The series of reactions involved are :