At $T(\mathrm{~K})$, the vapour pressure of an aqueous solution of a non-volatile solute, whose mole fraction is 0.02 is found to be 34.65 mm Hg . What is the vapour pressure (in mm Hg ) of pure water at the same temperature?

A centi molar solution of acetic acid is $50 \%$ dissociated at $27^{\circ} \mathrm{C}$. The osmotic pressure of the solution (in atm ) is $\left(R=0.083 \mathrm{~L}\right.$ atm $\left.\mathrm{K}^{-1} \mathrm{~mol}^{-1}\right)$

At 300 K vapour pressure of a pure liquid. ' $A$ ' is 70 mm Hg . It forms an ideal solution with another liquid ' $B$ '. The mole fraction of $B$ in the solution is 0.2 and total vapour pressure of solution is 84 mm Hg at same temperature. What is the vapour pressure (in mm ) of pure liquid $B$ at 300 K ?

248 g of ethylene glycol $\left(\mathrm{C}_2 \mathrm{H}_6 \mathrm{O}_2\right)$ is added to 200 g of water to prepare antifreeze. What is the molality of resultant solution?

$$ (\mathrm{C}=12 \mathrm{u} ; \mathrm{H}=1 \mathrm{u} ; \mathrm{O}=16 \mathrm{u}) $$