In a liquid mixture of $A$ and $B$,what is the mole fraction of $A$ in the vapor phase $(X_A = 0.4)$? Given: $P_A^o = 100 \, mm \, Hg$ and $P_B^o = 200 \, mm \, Hg$.

Two liquids $A$ and $B$ have $P_A^o$ and $P_B^o$ in the ratio of $1 : 3$ and the ratio of number of moles of $A$ and $B$ in the liquid phase is $1 : 3$. The mole fraction of $A$ in the vapour phase in equilibrium with the solution is equal to:

Vapour pressure of pure water at $298 \, K$ is $23.8 \, mm \, Hg$. $50 \, g$ of urea $(NH_2CONH_2)$ is dissolved in $850 \, g$ of water. Calculate the vapour pressure of water for this solution and its relative lowering.

Calculate the vapour pressure of pure volatile liquid $B$ $(P_B^o)$ at a given temperature if the mole fraction of liquid $B$ $(x_B)$ is $0.4$ and the vapour pressure of pure volatile liquid $A$ $(P_A^o)$ is $400 \ mm \ Hg$. The total vapour pressure of the solution is $P_{total} = 600 \ mm \ Hg$. (in $mm \ Hg$)

The vapour pressure of water at room temperature is $23.8 \ mm \ Hg$. The vapour pressure of an aqueous solution of sucrose with mole fraction of $0.1$ is equal to .......... $mm \ Hg$.

Vapour pressure of a pure solvent at $90\,^{\circ}C$ is $1020\, torr$. $A$ solution of $0.1\, m$ concentration has a vapour pressure of $1000\, torr$. What is the molecular weight of the solvent?