Raoult’s law states that a solvent’s partial vapour pressure in a solution (or mixture) is equal or identical to the pure solvent’s vapour pressure multiplied by its mole fraction in the solution. 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.