`[X] +H_(2)SO_(4) to ` [Y] colourless with irritating smell. [Y] +`K_(2)Cr_(2)O_(7)+H_(2)SO_(4) to ` green solution
[X] and [Y] are

Options

A. `SO_(3)^(2-),SO_(2)`
B. `Cl^(-),HCl`
C. `S^(2-),H_(2)S`
D. `CO_(3)^(2-),CO_(2)`

Explanation

`X=SO_(3)^(2-)` ions, `Y=SO_(2)`
`underset("(X)")(XO_(3)^(2-))+H_(2)SO_(4) to underset("(Y)")(SO_(2))+H_(2)O +SO_(4)^(2-)`
`underset("(Y)")(3SO_(2))+K_(2)Cr_(2)O_(7)+H_(2)SO_(4) to K_(2)SO_(4) +underset("(Green)")(Cr_(2)(SO_(4))_(3))+H_(2)O`