When a non-volatile solute is added to a pure solvent,the vapor pressure decreases by $11.5 \ torr$. If the mole fraction of the solute is $0.2$,what will be the vapor pressure of the pure solvent in $torr$?

Calculate the mole fraction of solute in a solution if the vapour pressure of the solution and the pure solvent are $27 \text{ mm Hg}$ and $30 \text{ mm Hg}$ respectively at $298 \text{ K}$.

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 $CCl_4 = 1.58\,g/cm^3$).

The vapor pressure of a mixture of $300 \ mL$ of ethyl alcohol and propyl alcohol is $290 \ mm$. The vapor pressure of propyl alcohol is $200 \ mm$. If the mole fraction of ethyl alcohol is $0.6$,what will be its vapor pressure (in $mm$) at the same temperature?

On adding a solute to a solvent having a vapour pressure of $0.80 \ atm$,the vapour pressure reduces to $0.60 \ atm$. The mole fraction of the solute is:

Which of the following will have the lowest vapor pressure?