Vinegar- #44

Vinegar's chemical formula is CH3COOH.
C- 12.011 X 2 = 24.022
H- 1.00 X 4 = 4.00
O- 16.00 X 2 = 32.00
TOTAL: 60.022

C- 24.022/60.022 = 40%
H- 4.00/60.022 = 6.7%
O- 32.00/60.022 = 53.3%

Source:

http://chemistry.about.com/od/molecularformulas/a/Vinegar-Chemical-Formula.htm