Consider two cylinder piston assembly as shown in figure (a) and in figure (b) are kept in vacuum. Assume both piston are massless. Let two masses `m_(1)` and `m_(2)` are kept on the piston as shown in figure. Values of `m_(1)` and `m_(2)` are in the range in which both liquid and vapour phase coexist and are in equilibrium.

Solution I contains `10` moles of liquid A and 10 moles of liquid B while solution II contains 8 moles of liquid A and 12 moles of liquid B. Let liquids A and B are completely miscible and form an ideal binary solution.
Given : `P_(A)^(@) = 100` torr, `P_(B)^(@) = 60` torr,
Let `X_(A) =` mole fraction of A in liquid phase in solution I
`X'_(A) =` mole fraction of A in liquid phase in solution II
`Y_(A) =` mole fraction of A in vapour phase in solution I
`Y'_(A) =` mole fraction of A in vapour phase in solution II
Mole fraction of A in liquid phase when `10` moles of solution is vapoursied in solution II is :

Options

A. `0.45`
B. `0.632`
C. `0.25`
D. `0.34`

Answer

B