Pure drinkin alcohol has a specific gravity SG0785 Pure wate

Pure drinkin’ alcohol has a specific gravity SG=0.785. Pure water has SG=1.0. 200 proof is pure alcohol, 100 proof is 50% alcohol etc. ( 1% alcohol = 2 proof).

a) Show that the specific gravity of 80 proof “adult beverage” (assume a mix of alcohol and water only) is SG=0.914.

Solution

alchohol is mixed with water. Total of 200 proof.

SG of mixture = (0.785*80+1*120)/(200) { 120 because 80 for alcohol and remaining 120 for water}

=0.914