Vapour pressure of solvent is $17.5 \ mm \ Hg$ while that of dilute solution is $17.45 \ mm \ Hg$; the mole fraction of solvent is

$38.4 \ g$ of unknown substance (molar mass $384 \ g \ mol^{-1}$) and $116 \ g$ of acetone is used to prepare a solution at $313 \ K$. If vapour pressure of pure acetone (molar mass $58 \ g \ mol^{-1}$) is $0.842 \ atm$,what is the vapour pressure of the solution (in $atm$)?

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

Calculate the vapour pressure of the solution if the relative lowering of vapour pressure and the vapour pressure of the pure solvent are $0.018$ and $18 \ mm \ Hg$ respectively at $300 \ K$. (in $mm \ Hg$)

Calculate the vapour pressure of pure volatile liquid $A$ at a given temperature if the mole fraction and vapour pressure of pure volatile liquid $B$ are $0.4$ and $900 \ mm \ Hg$ respectively,given that the total vapour pressure of the solution is $600 \ mm \ Hg$. (in $mm \ Hg$)

When a non-volatile,non-electrolyte solute is dissolved in a solvent,the vapor pressure of the solution decreases by $8\%$. The mole fraction of the solute is .............