Question

An ideal solution has two components $A$ and $B$. If $A$ and $B$ .If $A$ is more volatile than $B$ and also $P_{A}^{\circ} >\,P_{T}$ then the correct relation between mole fraction of $A$ in liquid (X) and vapour (Y) phase is:

• A. $X_{A}=Y_{A}$
• B. $X_{A}>\,Y_{A}$
• C. $X_{A} <\,Y_{A}$
• D. Nothing can be said

Answer 1

Answer: (C)

$P_{A}^{\circ} X_{A} =P_{T}. Y_{A}$
$\therefore \frac{X_{A}}{Y_{A}}=\frac{P_{T}}{P_{A}^{0}} <\,1$
$X_{A} <\,Y_{A}$