If two substances $A$ and $B$ have $P_A^0 : P_B^0 = 1 : 2$ and have mole fraction in solution $1 : 2$,then what is the mole fraction of $A$ in the vapour phase?

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

The vapour pressure of pure benzene at a certain temperature is $0.850 \ bar$. $A$ non-volatile,non-electrolyte solid weighing $0.5 \ g$ when added to $39.0 \ g$ of benzene (molar mass $78 \ g \ mol^{-1}$),the vapour pressure of the solution becomes $0.845 \ bar$. What is the molar mass of the solid substance?

The vapor pressures of two pure liquids $(A)$ and $(B)$ are $100 \ Torr$ and $80 \ Torr$ respectively. What is the total vapor pressure of the solution formed by mixing $2 \ moles$ of $(A)$ and $3 \ moles$ of $(B)$ (in $Torr$)?

Relative lowering of vapour pressure of a dilute solution is $0.5$. What is the mole fraction of the non-volatile solute?

The boiling points of $C_6H_6$,$CH_3OH$,$C_6H_5NH_2$,and $C_6H_5NO_2$ are $80 \, ^\circ C$,$65 \, ^\circ C$,$184 \, ^\circ C$,and $212 \, ^\circ C$ respectively. Which one exhibits the maximum vapor pressure at room temperature?