Explain why does colour of KMnO4 disappear when oxalic acid is added to its solution in acidic medium?

NEETprep Answer: When oxalic acid is added to acidic solution of    . Its colour disappear due to reduction of    . Chemical reaction occuring during this neutralisation reaction is as follows
   5C2O42- + 2MnO4- + 16H+              2Mn2+      + 8H2O + 10CO2
                       (Coloured)                          (Colourless)