Thanks for your help; I am still have a few problems, could you check my work:
Given: Volume of vinegar analyzed-5mL
Con'c of NaOH-0.09890M
Avg. Volume of NaOH from titration-43.75mL
Density CH3COOH: 1.049g/mL
1.Moles of NaOH required to reach equivalence point= M X L
(0.09890M)(0.04375L)= 0.004327 moles.
2.Moles of acetic acid 5.00mL of vinegar= M X L
(what do I do if the con'c of acetic isn't given)(0.0500L)=?
3. Mass of acetic acid in the 5.00mL sample of vinegar= Mol X MM (0.004327 mol)(60.01g/mol)=0.2529g
4. Volume of the acetic acid in the 5.00mL sample of vinegar
5. % by volume of acetic acid in the vinegar (0.2724mL)/(5.00mL)X 100%= 5.45%
Please let me know if this looks correct.