Raoult’s law states that the relative lowering of the vapour pressure of a solvent by dissolving a non-volatile electrolyte is equal to the mole fraction of the solute.
Raoult’s law equation is written mathematically as;
Psolution = ΧsolventP0solvent
Psolution = vapour pressure of the solution
Χsolvent = mole fraction of the solvent
P0solvent = vapour pressure of the pure solvent
A solution that obeys Raoult’s law is known as the ideal solution. This law is established by French chemist François-Marie Raoult in 1887.