When `cO_(2)` is passed into aqueous:

Options

A. `Na_(2)CrO_(4)` solution , its yellow colour change to orange
B. `K_(2)MnO_(4)` Solution,it disproportionate to `KMnO_(4)` and `MnO_(2)`
C. `Na_(2)Cr_(2)O_(7)` Solution,its orange colour change to green
D. `KmnO_(4)` Solution ,its pink colour change to green.

Explanation

`Na_(2)CrO_(4)undersetto(H^(+))Na_(2)Cr_(2)O_(7)("oranged colour")`
(B)`MnO_(4)^(2-) undersetto(H^(+))MnO_(4)^(-)`
(C )False-in acidic medium no colour change take place.
(D)`MnO_(4)^(-)+e^(-)undersetto(Oh^(-))MnO_(4)^(2-)`, in strong alkaline medium pink colour of `KMO_(4)` changes to green. Therefore , (A,B) option are correct