Answer:
0.291
Explanation:
Given data
- Vapor pressure of the pure solvent (Psolvent): 1.41 atm
1070 torr × (1 atm/ 760 torr) = 1.41 atm
- Vapor pressure of the solvent above the solution (Psolution): 1.00 atm
According to Raoult's law, the vapor pressure of a solvent above a solution is equal to the vapor pressure of the pure solvent at the same temperature scaled by the mole fraction of the solvent present.
Psolution = Psolvent × Χsolvent
Χsolvent = Psolution/Psolvent
Χsolvent = 1.00 atm/1.41 atm
Χsolvent = 0.709
The sum of the mole fraction of the solvent (water) and the solute (ethylene glycol) is 1.
Χsolvent + Χsolute = 1
Χsolute = 1 - Χsolvent = 1 - 0.709
Χsolute = 0.291
