Which of the following will have the lowest vapour pressure?

$A$ 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?

The weight in grams of a non-volatile solute (mol. wt. $60$) to be dissolved in $90 \ g$ of water to produce a relative lowering of vapour pressure of $0.02$ is

At $30^\circ C$,liquid $A$ and $B$ form an ideal solution. The total vapor pressure of a solution containing $1 \ mol$ of $A$ and $2 \ mol$ of $B$ is $250 \ mm \ Hg$. The total vapor pressure becomes $300 \ mm \ Hg$ when $1 \ mol$ more of $A$ is added to the first solution. What are the vapor pressures of pure $A$ and $B$ at the same temperature?

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

Vapour pressure of $CCl_4$ at $25\,^{\circ}C$ is $143\,mm$ of $Hg$. $0.5\,g$ of a non-volatile solute (mol. wt. $= 65$) is dissolved in $100\,mL$ $CCl_4$. Find the vapour pressure of the solution (Density of $CCl_4 = 1.58\,g/cm^3$).