A 10.1 mL sample of vinegar, which is an aqueous solution of acetic acid, HC2H3O2, requires 16.2 mL of 0.474 M NaOH to reach the end point in a titration. What is the molarity of the acetic acid solution? HC2H3O2(aq) + NaOH(aq) ? NaC2H3O2(aq) + H2O(l)