Question

For an ideal binary liquid solution with `"p"_"A"^circ > "P"_"B"^circ`, which is a relation between X_A (mole fraction of A in liquid phase) and Y_A (mole fraction of A in vapour phase) is correct, X_B and Y_B are mole fractions of B in liquid and vapour phase respectively?

Options

• X_A = Y_A

• X_A > X_B

• `"X"_"A"/"X"_"B" < "Y"_"A"/"Y"_"B"`

• X_A, Y_A, X_B and Y_B cannot be correlated.

Answer 1

`"X"_"A"/"X"_"B" < "Y"_"A"/"Y"_"B"`

Explanation:

`"P""′"_"A"​ = "P"_"A"^0​ ​⋅ "X"_"A" ​= "P"_"M"​ ⋅ "Y"_"A"​`

`"P""′"_"B"​ = "P"_"B"^0​ ​⋅ "X"_"B" ​= "P"_"M"​ ⋅ "Y"_"B"​`

`therefore "P"_"A"^0/"P"_"B"^0  * "X"_"A"/"X"_"B" = "Y"_"A"/"Y"_"B"`

`because "P"_"A"^0/"P"_"B"^0 > 1`

`therefore "X"_"A"/"X"_"B" < "Y"_"A"/"Y"_"B"`