I think the answer you're looking for is, "about half."
16 grams of sugar will become eight grams of alcohol, in a situation where every molecule of sugar is fermented.
glucose --> ethanol + carbon dioxide
C6H12O6-->2 C2H6O + 2 CO2
180.1572 --> 92.1376 + 88.0196 (in grams per mole)
This...
