Question

For an ideal binary liquid solution with $p_x^0>p_y^0$ in which relation between $X_x$ (mole fraction of $x$ in liquid phase) and $Y_x$ (mole of fraction of $x$ in vapour phase) is correct where $X_y$ and $Y_y$ are mole fraction of $y$ in liquid and vapour phase respectively.

• A. $X_x>Y_x$
• B. $X_x=Y_x$
• C. $\frac{X_x}{X_y}<\frac{Y_x}{Y_y}$
• D. $X_x,Y_x,X_y$ and $Y_y$ cannot be correlated

Answer 1

The correct option is C $\frac{X_x}{X_y}<\frac{Y_x}{Y_y}$

For an ideal binary liquid solution with $p_x^0>p_y^0$
Hence, $x$ is more volatile than $y$. The vapour pressure of $x$ will be more than the vapour pressure of $y$. The mole fraction of $x$ in the vapour phase will be more than the mole fraction of $y$ in the vapour phase.
Hence, $\frac{X_x}{Y_x}<\frac{X_y}{Y_y}$

or, $\frac{X_x}{X_y}<\frac{Y_x}{Y_y}$