Question

At ${25}^{\circ }C,$ the vapour pressure of methyl alcohol is 96.0 torr. The mole fraction of $C{H}_{3}OH$ in solution in which the (partial) vapor pressure of $C{H}_{3}OH$ is 23.0 torr at ${25}^{\circ }C$ is $\frac{x}{y}$. Find $y-x$.

Answer 1

Formula for partial pressure is
$P_A=P_A^{\circ }.X_A$
Here total pressure and partial pressure is known. So using above formula we get
$23=96\ast X_A$
Ans-0.24