Question

Write the expression that correlates molal elevation constant to molar enthalpy of vaporisation.

Answer 1

Molal elevation constant (K_b) for a particular solvent can be calculated from the following relationship.

`K_b = (MRT_b)/(1000 xx Delta H_v)`

Where, T_b = Boiling point of solvent

ΔH_v = Molar enthalpy of vaporisation of solvent (Latent heat of vaporisation for one mole of the solvent)

M = Molecular mass of solvent

R = Gas constant