A sample of oxalic acid, H2C2O4, was analyzed using a standardized solution of KMnO4. 25.0mL of oxalic acid is titrated after heating. 12.30 mL of a 0.0226 M KMnO4 was added to the sample when a faint pink color was observed. The balanced equation for this reaction is shown: 6 H+(aq) + 2 MnO4-(aq) + 5 H2C2O4(aq) → 10 CO2(g) +8 H2O(l) + 2Mn2+(aq)

Question: If the density of the oxalic acid solution was 1.00 g/mL, what was the percentage by mass of oxalic acid in the solution?