Calculate the freezing point of a solution of a non-volatile solute in a unknown solvent of molar mass 30 g/mol having mole fraction of solvent equal to 0.8. Given that latent heat of fusion of solid solvent = 2.7 kcal `mol(-1)k^(-1)`, freezing point of solvent =`27^@C` and R = 2 cal `mol^(-1) k^(-1)