You measure 2.34 grams of potassium dichromate K2Cr2O7 into a volumetric flask. You dilute the potassium dichromate K2Cr2O7 with H2O to a volume of 250 mili litres. It takes 35.7 mL of this solution to titrate 17.8 mL of a solution of Sodium oxalate, or disodium oxalate in the presence of excess acid. Determine the concentration of the original Na2C2O4 solution?