Question

160g of alcohol is mixed with 500cm^3 of water . The volume of the mixture becomes 690cm^3 and density of water is 1 gcm^-3. What is the density of the mixture. Show working please.

Answer 1

mass of alcohol= 160g
volume of water=500cm^3
volume of mixture= 690cm^3
volume of alcohol= vol of mixture - vol of water=190cm^3
density=mass/volume
Now, what's the density of alcohol? Then, add alcohol density with water density and you get density of mixture.

Answer 2

density of mixture = total mass / total volume

mass always adds up strictly, so total mass = mass of alcohol + mass of water.