A sample of an ethanol water solution has a volume of 50.0 cm^3 and a mass of 50.0g . what is the percentage of ethanol by mass in solution? assume that there is no change in volume when the pure compounds are mixed.The density of ethanol is a 0.80
Answers
Explanation:
(law of chemical combination)
Let the volume of ethanol ⇒x
Volume of water =55−x
Density =
volume
mass
∴ mass =density × volume
Mass of ethanol =0.8×x
Mass of water 2x(55−x)
Total mass =50
0.8x+(55−x)=50
0.8x−x+55=50
−0.2x+55=50
55−50=0.2r
0.2
5
=x
∴x=25
Volume of ethanol =25
Volume of water 55−x=55−25=30
∴ Mass of ethanol =0.8×.25=00 gm
Mass of water =(55−x)×1=30 gm
% By mass of ethenol =
50
20
×100=40%
Answer:
(law of chemical combination)
Let the volume of ethanol ⇒x
Volume of water =55−x
Density =
volume
mass
∴ mass =density × volume
Mass of ethanol =0.8×x
Mass of water 2x(55−x)
Total mass =50
0.8x+(55−x)=50
0.8x−x+55=50
−0.2x+55=50
55−50=0.2r
0.2
5
=x
∴x=25
Volume of ethanol =25
Volume of water 55−x=55−25=30
∴ Mass of ethanol =0.8×.25=00 gm
Mass of water =(55−x)×1=30 gm
% By mass of ethenol =
50
20
×100=40%