The concentration of a phosphoric acid solution is determined by titration against a 0.00215 g sample of pure NaOH using phenolphthalein indicator. What is the concentartion of the phosphoric acid solution if it required 25.12 mL of phosphoric acid to titrate the NaOH sample when dissolved in water?
3NaOH (s) + H3PO4 (aq) + 3H2O (l)