Boiling point of a liquid is the temperature at which vapour pressure of liquid becomes equal to atmospheric pressure. As the vapour pressure of solution is lower than that of solvent, its boiling point is higher.
ΔTb = Kb m
If m = 1, ΔTb = Kb
Kb = Molal elevation constant / ebullioscopic constant
Ebullioscopic Constant
It is the elevation in boiling point when the molality of solution is unity.
SI unit : K kg mol-1
\(T^0_b\) = boiling point of solution
\(T^0_b\) = boiling point of pure solvent
wA = given mass of solvent
wB = given mass of solute
MB = molecular mass of solute
Relationship between Kb and enthalpy of vaporisation (Δvap H)
Relationship between Kb and latent heat of vaporisation (lv)
