Molal elevation constant or ebullioscopic constant is defined as the elevation in boiling point when one mole of non-volatile solute is added to one kilogram of solvent. Ebullioscopic constant (Eb) is the constant that expresses the amount by which the boiling point T b of a solvent is raised by a non-dissociating solute. Its units are K Kg mol-1.
Δ Tb = Ebb
b is the molality of the solute.