Explain why does colour of `KMnO_(4)` disappear when oxalic acid is added to its solution in acidic medium?

Explanation

When oxalic acid is added to acidic solution of `KMnO_(4)`, its colour disappear due to reduction of `MnO_(4)^(-)` ion to `Mn^(2+)`. Chemical reaction occuring during this neutralisation reaction is as follows
`5C_(2)O_(4)^(2-)+underset(("Coloured"))(2MnO_(4)^(-))+16H^(+)rarrunderset(("Colourless"))(2Mn^(2+))+8H_(2)O+10CO_(2)`