It is well known that the vapor pressure of a solvent liquid is lowered by dissolving a nonvolatile solute in it. The experiments of Wiillner (Pogg. Ann. 110, 56. 1860) indicated that if the solute is nonvolatile, nonelectrolytic, and without chemical action on the solvent, the vapor pressure of the solvent is lowered by an amount proportional to the concentration of the solute; concentration being in this case defined as the ratio of the mass of the solute to the mass of the whole solution, i.e., the mass fraction. Nearly thirty years after Wiillner's work, Raoult (Zeits. Phys. Chem. 2, 353. 1888) gave a more explicit statement of the same law, to the effect that the ratio of the change in vapor pressure to the original vapor pressure of the solvent is equal to the mole fraction of the solute.
Proceedings of the Iowa Academy of Science
©1943 Iowa Academy of Science, Inc.
Weld, Le Roy D.
"Simple Proof of Wüllners Vapor Pressure Law,"
Proceedings of the Iowa Academy of Science, 50(1), 289-290.
Available at: https://scholarworks.uni.edu/pias/vol50/iss1/25