



 
Hi Andrew. I am assuming you want to know the mass of the vodka mixture, not just the mass of the alcohol. Either way, the density is what matters here. The density of alcohol is 0.79 g/ml and the rest of the vodka mixture is water, which is 1.00 g/ml (the flavourings don't really affect things much). "80 proof" means 40% of the volume is alcohol. So if you have x milliliters of 80 proof vodka, it weighs (60%)(1.00)x + (40%)(0.79)x grams, which works out to 0.916x grams. Hope this helps, On October of 2017 we received the following note from Pete, a teacher.
Thanks Pete.  


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