A 5.00-g sample of vinegar is titrated with 0.108 M NaOH. If the vinegar requires 39.1 mL

Question:

A 5.00-g sample of vinegar is titrated with 0.108 M NaOH. If the vinegar requires 39.1 mL of the NaOH solution for complete reaction, what is the mass percentage of acetic acid, HC2H3O2, in the vinegar? The reaction is
HC2H3O2(aq) + NaOH(aq) → NaC2H3O2(aq) + H2O(l )