A solution of $$8 \mathrm{~g}$$ of certain organic compound in $$2 ~\mathrm{dm}^3$$ water develops osmotic pressure $$0.6 \mathrm{~atm}$$ at $$300 \mathrm{~K}$$. Calculate the molar mass of compound. [R = 0.082 atm dm$$^3$$ K$$^{-1}$$ mol$$^{-1}$$]

Which from the following compound solutions in water of equal concentration has electrical conductivity nearly same as distilled water?

A solution of nonvolatile solute is obtained by dissolving $$1 \mathrm{~g}$$ in $$100 \mathrm{~g}$$ solvent, decreases its freezing point by $$0.3 \mathrm{~K}$$. Calculate cryoscopic constant of solvent if molar mass of solute is $$60 \mathrm{~g} \mathrm{~mol}^{-1}$$.

Which among the following gases exhibits very low solubility in water at room temperature?