According to the balanced equation shown below, 1.00 mole of oxalic acid, h2c2o4, reacts with moles of permanganate ion, mno4-

The balanced equation that shows the reaction between oxalic acid and permanganate ion in an acidic medium is: 2MnO4- + 5H2C2O4 + 6H+ -> 2Mn(2+) + 10CO2 + 8H2O. Thus, 1 mole of oxalic acid reacts with 0.4 mole of permanganate ion. This was obtained using stoichiometry:

1 mol H2C2O4 x (2 mol MnO4-/ 5 mol H2C2O4) = 0.4 mol MnO4- 

In this redox reaction, the permanganate is reduced to manganese(II) ion.