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.

How many grams of a non-volatile solute (molar mass $40 \ g/mol$) must be added to $114 \ g$ of octane to reduce its vapour pressure by $20\%$ (in $g$)?

For a binary solution, when a nonvolatile nonelectrolyte solute is dissolved in a solvent, the vapour pressure of the solvent decreases by $20 \%$. What is the mole fraction of the solvent in the solution?

The total vapour pressure of a solution of liquid $A$ and liquid $B$ is $600 \ torr$. The mole fraction of component $A$ in the liquid phase is $0.7$. If the mole fraction of $A$ in the vapour phase is $0.35$,what are the vapour pressures of pure $A$ and pure $B$ respectively?

$2\, \text{moles}$ of liquid $A$ is mixed with $3\, \text{moles}$ of liquid $B$. Calculate the mole fraction of $A$ in the vapour phase if $P_A^o = 100\, \text{mm}$ and $P_B^o = 200\, \text{mm}$.

An aqueous solution of methanol in water has a vapour pressure: