Answer to Question #43596 in Physical Chemistry for najma

Question

freezing point of pure solvents higher than freezing point solution in which non-volatile solute dissolve justify

Answer 1

If the solution is treated as an ideal solution, the extent of freezing point depression depends only on the solute concentration that can be estimated by a simple linear relationship with the cryoscopic constant ("Blagden's Law"):
ΔT = i∙b∙K_f
where ΔT is temperature depression, i is the van 't Hoff factor, b is the molality (mol solute per kg of solvent), K_f is the cryoscopic constant.
According to this formula, the freezing point depression linearly increases with increase of the solute concentration.