Question

Two liquids X and Y are perfectly immiscible. If X and Y have molecular masses in ratio 1:2, the total
vapour pressure of a mixture of X and Y prepared in weight ratio 2:3 should be (Pxº = 400 torr,
Py = 200 torr)
(A) 300 torr
(B) 466.7 torr
(C) 600 torr
(D) 700 torr​

Answer 1

The total vapour pressure = c) 600 torr

• Given, two liquids X and Y
• Ratio of molar masses = X:Y = 1:2
• Ratio of masses = X : Y = 2:3
• Partial pressure of X = 400 torr
• Partial pressure of  Y = 200 torr
• Now, we know,                                                                                                        Total vapour pressure of two immiscible liquids = sum of partial vapour pressure of both the liquids.
• So, total vapour pressure = 400 + 200 = 600 torr.

Answer 2

Answer:

total vapour pressure= px°+py°

=400+200

=600