In acidic medium which of the following does not change its colour:

Options

A. `MnO_(4)^(-)`
B. `MnO_(4)^(2-)`
C. `CrO_(4)^(2-)`
D. `FeO_(4)^(2-)`

Answer

A

Explanation

`MnO_(4)^(-)` stable in acidic medium
`MnO_(4)^(2-)` disproportionate
`CrO_(4)^(2-)` Convert into `Cr_(2)O_(7)^(2-) and FeO_(4)^(2-)` decompose