The number of pairs of the solutions having the same value of the osmotic pressure from the following is _________.

(Assume 100% ionization)

A. 0.500 $$\mathrm{M~C_2H_5OH~(aq)}$$ and 0.25 $$\mathrm{M~KBr~(aq)}$$

B. 0.100 $$\mathrm{M~K_4[Fe(CN)_6]~(aq)}$$ and 0.100 $$\mathrm{M~FeSO_4(NH_4)_2SO_4~(aq)}$$

C. 0.05 $$\mathrm{M~K_4[Fe(CN)_6]~(aq)}$$ and 0.25 $$\mathrm{M~NaCl~(aq)}$$

D. 0.15 $$\mathrm{M~NaCl~(aq)}$$ and 0.1 $$\mathrm{M~BaCl_2~(aq)}$$

E. 0.02 $$\mathrm{M~KCl.MgCl_2.6H_2O~(aq)}$$ and 0.05 $$\mathrm{M~KCl~(aq)}$$

The osmotic pressure of solutions of PVC in cyclohexanone at 300 K are plotted on the graph.

The molar mass of PVC is ____________ g mol$$^{-1}$$ (Nearest integer)

(Given : R = 0.083 L atm K$$^{-1}$$ mol$$^{-1}$$)

The total pressure observed by mixing two liquids A and B is 350 mm Hg when their mole fractions are 0.7 and 0.3 respectively.

The total pressure becomes 410 mm Hg if the mole fractions are changed to 0.2 and 0.8 respectively for A and B. The vapour pressure of pure A is __________ mm Hg. (Nearest integer)

Consider the liquids and solutions behave ideally.

$$1.80 \mathrm{~g}$$ of solute A was dissolved in $$62.5 \mathrm{~cm}^{3}$$ of ethanol and freezing point of the solution was found to be $$155.1 \mathrm{~K}$$. The molar mass of solute A is ________ g $$\mathrm{mol}^{-1}$$.

[Given : Freezing point of ethanol is 156.0 K.

Density of ethanol is 0.80 g cm^$$-$$3.

Freezing point depression constant of ethanol is 2.00 K kg mol^$$-$$1]