Question

10 moles each of a and b are mixed to obtain an ideal.solution in a closed container at 300 k . if p°a = 200 torr and p°b = 800 torr . find the vapour density of the solution when half of the mixture has been vaporized​

Answer 1

Correct option is D)

Let P be the total pressure. Let x be the number of moles of A in the liquid state.

The number of moles of the vapour state will be 10−x.

Let y be the number of moles of B in the liquid state

The number of moles of B in vapour state will be 10−y.

Hence, x+y=10

P×

(10−x+10−y)

(10−x)

=200×

(x+y)

(x)

P×

(10−x+10−y)

(10−y)

=

(x+y)

100×(y)

These equations are solved for x, y and P.

x=4.142

y=5.858

P=141.4 mm Hg