Hey guys, I'm having a problem with this question; Malonic Acid, C3H4O4, is a diprotic acid. How many grams of it are in a 30mL sample that requires 35mL of 2M NaOH for complete neutralization? Since Malonic Acid is diprotic, I think the chemical equation is; C3H4O4 + 2NaOH --> Na2C3H2O4 + 2H2O . I knw that if the equation is true, the stoichiometric ratio of NaOH : C3H4O4 is 2 : 1 so the number of moles of Malonic Acid is 0.5 x (2 x (35 / 1000)mol = 0.035mol . Hence, the mass of Malonic Acid required would be 0.035mol x molar mass. However, how did the 30mL fit in? Thanks.