Question

The following graph represents variation of boiling point with composition of liquid and vapours of binary liquid mixture. The graph is plotted at constant pressure. Which of the following statement(s) is incorrect. Here X & Y stands for mole fraction in liquid and vapour phase respectively

• A. $X_{benzene}=0.5and{Y}_{toluene}=0.2$
• B. $X_{toluene}=0.3and{Y}_{benzene}=0.6$
• C. $X_{benzene}=0.3and{Y}_{toluene}=0.4$
• D. if $X_{benzene}=0.7than{Y}_{toluene}<0.3$

Answer 1

Answer: (B)

$X_{toluene}=0.3and{Y}_{benzene}=0.6$

When the mole fraction of toluene in liquid is 0.3, the mole fraction of benzene in liquid is 0.7.
The liquid is in equilibrium with vapour.
The mole fraction of benzene in vapour is 0.6 and the mole fraction of toluene in vapour is 0.4.
Hence, option B is the correct option.