Question

At 300 K the vapour pressure of an ideal solution containing 1.0 mole each of volatile liquids X and Y is 1000 mm. Keeping the temperature constant, when 2.0 moles of liquid X are added to the solution, its vapour pressure increases by 200 mm. Calculate the vapour pressure of X and Y in their pure state.

• A. \( P_X^0 = 1400,\; P_Y^0 = 600 \)
• B. \( P_X^0 = 1700,\; P_Y^0 = 400 \)
• C. \( P_X^0 = 1200,\; P_Y^0 = 480 \)
• D. \( P_X^0 = 1000,\; P_Y^0 = 500 \)

Hint:

For ideal solutions, always use Raoult's law and form simultaneous equations based on mole fractions before and after change.

Answer 1

The Correct Option is A