Volatile and non-volatile solutes in solution
A substance with higher vapour pressure vaporizes more readily than a substance with a lower vapour pressure. In case of a volatile solute this has a high vapour pressure and hence produces vapour. While in the case of a non-volatile solute due to its lower vapour pressure it does not produce vapour. The vapor pressure of a substance is the pressure at which its gas phase is in equilibrium with its condensed phases (liquid or solid).