Posted by stacey on .
what is the theoretical value for the M of acetic acid in vinegar if the vinegar is 5% acetic acid by a % mass value.
Additional info: the experimental M of the acetic acid in vinegar is 0.80M
Thank you!!

chemistry 
DrBob222,
It isn't possible to calculate the theoretical molarity of vinegar without know the density. I tried looking up the density of vinegar on the net and found values all the way from 0.96 g/mL to 1.08 g/mL (and some said 5% by mass and other 5% by volume).
5% by mass vinegar means 5 g CH3COOH/100 g solution. 5 g is 5/60.05 = 0.083 moles/100 g soln. If the density of the vinegar is 1.00 g/mL then the M = 0.083/0.1 = 0.83 M.
If you know the density, then volume = mass/density = 100/density and moles/L = M.