Addition of non-volatile solute to a solvent always inceases the colligative properties such as osmotic pressure, `DeltaP, DeltaT_(b)` and `DeltaT_(f)`. All these colligative properties are direactly propertional to molality if solutions are dilute. The increase in colligative properties on addition of non-volatile solute is due to incease in number of solute particles.
For different aqueous solutions of `0.1 N NaCl, 0.1 N` urea, `0.1 N Na_(2)SO_(4)` and `0.1 N Na_(3)PO_(4)` solution at `27^(@)C`, the correct statement are :
(P) The order of osmotic pressure is, `NaCl gt Na_(2)SO_(4) gt Na_(3)PO_(4) gt ` urea
(Q) `pi = (DeltaT_(b))/(K_(b)) xx ST` for urea solution
(R) Addition of salt on ice increases its melting point
(S) Addition of salt on ice brings in melting earlier

Options

A. 2,3,4
B. 2,4
C. 1,2,3
D. 3,4

Answer

B