The main chemical in vinegar that is reacting with NaOH in the titration is acetic acid (HC2H3O2). The balanced chemical reaction is:
HC2H3O2 (aq) + NaOH (aq) → NaC2H3O2 (aq) + H2O (l)
Starting with 5.89 g of HC2H3O2, calculate the # of moles of NaOH that will be required to completely neutralize it using stoichiometry. Molar mass of HC2H3O2 = 60.05 g/mol. Mole ratio of HC2H3O2 to NaOH is 1:1.
5.89 g HC2H3O2 x (1 mol HC2H3O2 / 60.05 g HC2H3O2) x (1 mol NaOH / 1 mol HC2H3O2) = 0.0981 mol NaOH
Volume of NaOH needed to reach the end point is....
Molarity = mol / L
L = mol / Molarity
= 0.0981 / 0.0998 = 0.983 L
Volume in mL = 0.983 L x (1000 mL / 1 L) = 983 mL