Molal elevation constant:
Molal elevation constant can be defined as the elevation in boiling point produced when one mole of solute is dissolved in 1 kg i.e. 1000 g of the solvent. It is also known as the ebullioscopic constant.
Molal depression constant:
The freezing point depression of solutions of nonelectrolytes has been determined to be equal to the molality (m) of the solute times a proportionality constant called the molal freezing point depression constant