Boiling point elevation occurs when the boiling point of a solution becomes higher than the boiling point of a pure solvent. The temperature at which the solvent boils is increased by adding any non-volatile solute. A common example of boiling point elevation can be observed by adding salt to water. The boiling point of the water is increased.
Boiling point elevation, like freezing point depression, is a colligative property of matter. This means it depends on the number of particles present in a solution and not on the type of particles or their mass.
The amount of boiling point elevation can be calculated using the Clausius-Clapeyron equation and Raoult's law. For an ideal dilute solution:
Boiling Pointtotal = Boiling Pointsolvent + ΔTb
where ΔTb = molality * Kb * i
with Kb = ebullioscopic constant (0.52°C kg/mol for water) and i = Van't Hoff factor