Study the graph between partial pressure and mole fraction of some gases and arrange the gases P, Q, R and S dissolved in H$$_2$$O, in the decreasing order of their K_H values.

Given that the freezing point of benzene is $$5.48^{\circ} \mathrm{C}$$ and its $$\mathrm{K}_{\mathrm{f}}$$ value is $$5.12{ }^{\circ} \mathrm{C} / \mathrm{m}$$. What would be the freezing point of a solution of $$20 \mathrm{~g}$$ of propane in $$400 \mathrm{~g}$$ of benzene?

A solute $$\mathrm{X}$$ is found to exist as a dimer in water. A 4 molal solution of $$\mathrm{X}$$ shows a boiling point of $$101.04^{\circ} \mathrm{C}$$. What is the percentage association of $$\mathrm{X}$$ ? ($$\mathrm{K}_{\mathrm{b}}$$ for water $$=0.52 \mathrm{~K} / \mathrm{m}$$).