An ideal solution is any solution which obeys Raoult's law.

Raoult's law gives the relationship between a solution's vapor pressure and a solvent's vapor pressure when the solute has no measurable vapor pressure (is nonvolatile).

The law is stated as follows: "The partial pressure of a solvent over a solution, P1, is given by the vapor pressure of the pure solvent, P°1, times the mole fraction of the solvent in the solution, X1," or P1 = X1*P°1

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