wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

The vapour pressure of pure liquid is 70 Torr at 27oC. The vapour pressure of a solution of this liquid and another liquid (mole fraction 0.2) is 84 Torr at 27oC. The vapour pressure of pure liquid B at 27oC is?

A
140 Torr
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
280 Torr
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
160 Torr
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
200 Torr
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 140 Torr
Vapour Pressure of pure liquid A=70 torr (PoA)

Mole fraction of liquid B=0.2 (xB)

Thus mole fraction of liquid A=xA=1xB

Total vapour pressure =84 torr

P=xAPoA+xBPoB

84=(0.8)×70+0.2×PoB

PoB =140 torr = vapour pressure of the pure liquid B

Hence, the correct option is A

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Liquids in Liquids and Raoult's Law
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon