Final answer:
Alcohol that is 80 proof equates to being 40% ethanol by volume. The 'proof' value is double the percentage of alcohol, thus 80 proof is 40% alcohol.
Step-by-step explanation:
Alcohol that is 80 proof is about 40% alcohol. In the proofing system, alcohol content is measured in terms of 'proof,' which is twice the percentage by volume of ethanol in an alcoholic beverage. Therefore, if a bottle of vodka is labeled as 80 proof, this translates to it being 40% ethanol by volume. This is a standard measure for spirits like vodka, where typical vodka has a proof value that indicates its alcohol content.
Alcohol that is 80 proof is about 40% alcohol. Proof is a measurement of the alcohol content in liquor and is double the percentage of alcohol by volume. So, if a liquor is 80 proof, it contains 40% alcohol by volume.