Properties of a solution which are dependent on the ratio of number of solute particles to the number of solvent molecules in a solution are known as colligative properties.
Lowering of vapor pressure and elevation in boiling point are basically two of the colligative properties which indirectly help to measure the molecular weight of a substance.
Thus, we can conclude that molar mass of the solute can be determined by measuring lowering of vapor pressure and elevation in boiling point.
