Solutions Question 311
Question: The vapour pressure of a solution of the liquids A ( $ P{}^\circ =80 $ mm Hg and $ x_{A}=0.4 $ ) and B ( $ P{}^\circ =120 $ mm Hg and $ X_{B}=0.6 $ ) is found to be $ 100mm $ Hg. It shows that the solution exhibits
Options:
A) positive deviation from ideal behaviour
B) negative deviation from ideal behaviour
C) ideal behaviour
D) positive deviation for lower cone. and negative for higher cone.
Show Answer
Answer:
Correct Answer: B
Solution:
$ P_{total}=P_A^{0}\times X_{A}+P_B^{0}\times X_{B} $
$ =80.0\times 0.4+120.0\times 0.6=104mm $ Hg The observed $ P_{total} $ is 100 mm Hg which is less than 104 mm Hg. Hence the solution shows negative deviation.
