A 42.0 mL sample of an NaOH solution is placed in a flask with a few drops of phenolphthalein (indicator). If 11.7 mL of a 0.325 M HCl solution is needed to reach the endpoint, what is the molarity of the NaOH solution?
NaOH(aq) + HCl(aq) H2O(l) + NaCl(aq)