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?

$$0.2 ~\mathrm{M}$$ aqueous solution of glucose has osmotic pressure 4.9 atm at $$300 \mathrm{~K}$$. What is the concentration of glucose if it has osmotic pressure $$1.5 \mathrm{~atm}$$ at same temperature?