He observed experimentally that - in liquid-vapor phase equilibrium of a mixture - the partial pressure of a vapor constituent is proportional to the mole fraction of that constituent in the solution.
Raoult also investigated freezing point depression of solvents when a small amount of solute is introduced. In 1882, Raoult published his results on the effects of nondissociating organic solutes, from which he deduced a general law controlling the lowering of freezing points. Four years later he extended this work to show the effect of solutes on a vapor pressure.
Raoult’s Law is strictly applicable to ideal liquid solutions at all compositions, pressures and temperatures. In an ideal of perfect solution, the components are mutually miscible in all proportions and there are no volume or thermal changes on mixing.
Raoult published the formulations of his laws in the Comptes rendus for 1882 and 1887.
Raoult’s Law
