$A$ solution contains a $1:4$ molar ratio of pentane and hexane. At $20^{\circ}C$,the vapor pressure of pure pentane is $440 \ mm \ Hg$ and that of hexane is $120 \ mm \ Hg$. What is the mole fraction of pentane in the vapor phase?

At $298 \ K$,the vapour pressure of a solution of $7.5 \ g$ of non-volatile solute in $90 \ g$ of water is $2.8 \ kPa$. If $18 \ g$ of water is added to this solution,the vapour pressure becomes $2.81 \ kPa$ at the same temperature. The molar mass of the solute in $g \ mol^{-1}$ is:

At $300 \ K$, the vapour pressure of toluene and benzene are $3.63 \ kPa$ and $9.7 \ kPa$ respectively. What is the composition of vapour in equilibrium with the solution containing $0.4$ mole fraction of toluene? (Assume the solution is ideal)

An aqueous solution is $1.00 \ molal$ in $KI$. Which change will cause the vapour pressure of the solution to increase?

The total vapour pressure of a solution of liquid $A$ and liquid $B$ is $600 \ torr$. The mole fraction of component $A$ in the liquid phase is $0.7$. If the mole fraction of $A$ in the vapour phase is $0.35$,what are the vapour pressures of pure $A$ and pure $B$ respectively?

Calculate the relative lowering of vapour pressure of a solution containing $3 \ g$ urea in $50 \ g$ water. [ Molar mass of urea $= 60 \ g \ mol^{-1} ]$