Na2C2O4 is the chemical formula for di-sodium oxalate. Di-sodium oxalate is soluble in water and its solubility is 3.7 grams per 100 milliliter of water at 20 degrees Celsius. Di-sodium oxalate reacts with water to form oxalic acid. The chemical formula for oxalic acid is H2C2O4. Sodium hydroxide is also produced during this reaction. The balanced chemical equation for the reaction is;