Question

$X$, $Y$ and $Z$ in the above graph are

• A. $X=p_1+p_2$, $Y=1$, $Z=0$
• B. $X=p_1+p_2$, $Y=0$, $Z=0$
• C. $X=p_1\times p_2$, $Y=0$, $Z=1$
• D. $X=p_1-p_2$, $Y=1$, $Z=0$

Answer 1

Answer: (B)

Here, $X=P_T=p_1+p_2=$ Total pressure of the solution.
$p_1$ and $p_2$ is the partial pressure of component $1$ and $2$ respectively.
$Y=x_2=$ mole fraction of component $2$ in the liquid phase.
$Z=y_2=$ mole fraction of component $2$ in the vapour phase.
When mole fraction of component $2$ in the liquid phase is $0$ then mole fraction of component $2$ in the vapour phase is also $0$ which means the liquid is pure of component $1$ only.