The liquids X and Y form an ideal solution at 300 K, vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mm Hg. At the same temperature, if 1 mol of Y is further added to this solution, vapour pressure of the solution increases by 10 mmHg. Vapour pressure (in mmHg) of X and Y in their pure states will be, respectively -

Options

A. 400 and 600
B. 500 and 600
C. 200 and 300
D. 300 and 400

Answer

A

Explanation

`550 = P_(A)^(@) xx (1)/(4) +P_(B)^(@) xx (3)/(4)`
`560 = P_(A)^(@) xx (1)/(5) +P_(B)^(@) xx (4)/(5)`
`P_(A)^(@) = 400 P_(B)^(@) = 600` tor