- It is the temperature at which the vapour pressure of liquid becomes equal to applied pressure. Means example of boiling of water on heat, boiling point of water is 100 celcius.
- For liquids in open container applied pressure is equal to the atmospheric pressure.
- Boiling point increases with increase in external pressure.
- Also liquids having greater intermolecular forces have high boiling points.
Elevation of boiling point :-
Vapour pressure of solution is less than that of pure solvent.
Therefore, it boils at high temperature. Thus there is elevation of boiling point of solvent when non-volatile solute is added in it.