Raoult’s law states that the vapour pressure of a solvent above a solution is equal to the vapour pressure of the pure solvent at the same temperature scaled by the mole fraction of the solvent present. A solution that obeys Raoult’s law over the entire range of concentration is called an ideal solution.
Raoult’s law equation is written as; Psolution = ΧsolventP0solvent.
Where p is the vapour pressure of a component of the solution, is the vapour pressure of pure component and X is the mole fraction of that component in the solution.