The vapour pressure of two pure isomeric liquids X and Y are 200 torr and 100 torr respectively at a given temperature. Assuming a solution of these components to obey Raoults law, the mole fraction of component X in vapour phase in equilibrium with the solution containing equal amounts of X and Y, at the same temperature is :

Options

A. 0.22
B. 5.55
C. 0.0555
D. 55.5

Answer

D

Explanation

For equimolar solution of X and Y.
` x_(x) = 0.5, x_(y) = 0.5`
`p_(X) = 0.5 xx 200 = 100 torr`
`p_(y) = 0.5 xx 100 = 50 torr`
`p_("tota") = 100 + 50 + 150 torr`
Mole fraction of component X in vapour phase, `y_(x) = (100)/(150) =0.67`