Addition of non-volatile solute to a solvent always increases the colligative properties such as osmotic pressure. `Delta P . Delta T_b` and `Delta T_f` . All these colligative properties are directly proportional to molality if solutions are dilute. The increases in colligative properties on addition of non-volatile solute is due to increases in number of solute particles.
For different aqueous solutions of 0.1 N NaCI, 0.1 N urea, 0.1 N `Na_2SO_4` and 0.1 N `Na_3PO_4` solution at `27^@C`, the correct statements are :
1. The order of osmotic pressure is NaCI = `Na_2SO_4 = Na_3PO_4` = urea
2. `pi` = `(Delta T_b)/k_b xx` RT for urea solution
3. Addition of salt on ice increases its melting point
4. Addition of salt on ice bring in melting of ice earlier

Options

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

Answer

B