Dear Student
Let V be the volume of density bottle whose mass is 35 g.
When filled with water the bottle weighs 65 g
Therefore, Mass of water in the bottle, mw = 65 – 35 = 30 g
Density of water = mw/V = 1 g/cc
=> V = 30 cc
So, the volume of the bottle is = 30 cc.
When filled with alcohol the bottle weighs 59 g.
So, mass of alcohol in the bottle, ma = 59 – 35 = 24 g
Therefore, density of the alcohol = ma/V = 24/30 = 0.8 g/cc
Relative Density = density of alcohol / density of water = 0.8 / 1 = 0.8
Regards