Liquid A and B from an ideal solution. If vapour pressure of pure A and B are 500 `Nm^(-2)` and 200 `Nm^(-2)` respectively , the vapour pressure of a solution of A in B containint 0.2 mole fraction of A would be

Options

A. `700 N m^(-2)`
B. `300 N m^(-2)`
C. `260 N m^(-2)`
D. `140 N m^(-2)`

Answer

C

Explanation

`P_(A) = X_(A) P_(A)^(o)=0.2 xx 500 = 100 N m^(-2)`
`P_(B)=X_(B)P_(B)^(o)=0.8 xx 200 = 160 N m^(-2)`
Total V.P. of the solution =`100+160=260Nm^(-2)`