The solution containing $$3 \mathrm{~g}$$ urea (molar mass 60 ) per $$\mathrm{dm}^3$$ of water and another solution containing $$4.5 \mathrm{~g}$$ of solute $$\mathrm{A}$$ per $$\mathrm{dm}^3$$ boils at same temperature, then what is molar mass of $$\mathrm{A}$$ ?

Vapour pressure of solution and of pure solvent are $$\mathrm{P}_1$$ and $$\mathrm{P}_1{ }^0$$ respectively. If $$\frac{P_1}{P_1^0}$$ is 0.15, find the mole fraction of solute.

According to Raoult's law mole fraction of solute in solution in given by formula

What is vapour pressure of solution containing 0.1 mole solute dissolved in $$1.8 \times 10^{-2} \mathrm{~kg} \mathrm{~H}_2 0$$ ? $$(\mathrm{P}_1^0=24 \mathrm{~mm} \mathrm{~Hg})$$