Question

Calculate the molality of ethyl alcohol solution in water if mole fraction of ethyl alcohol is 0.04

Answer 1

mole fraction=0.04
So if one molof solution contain 0.04 mol of ethanol and (1-0.04)molof water=0.96
So the mass of water=0.96*18 g=17.28g
So the mass of ethanol=0.04*46 g=1.84g
total mass=18.92g
Assuming the density of solution to be 1g/ml, the vlume of the solution=18.92ml
So if18.92ml of solution contain 0.04 mol of ethanol.
So …....1ml...............................0.04/18.92mol....
so 1000ml...............................(0.04/18.92)*1000=molaritty of the solution=2.11M