Solutions Question 121
Question: The vapour pressure of pure liquid A is 0.80 atm. On mixing a non-volatile B to A, its vapour pressure becomes 0.6 atm. The mole fraction of B in the solution is [MP PET 2003]
Options:
A) 0.150
B) 0.25
C) 0.50
D) 0.75
Show Answer
Answer:
Correct Answer: B
Solution:
According to Raoul’s Law $ \frac{P^{0}-P_{s}}{P^{0}}=x_{B} $ (Mole fraction of solute) $ x_{B}=\frac{0.8-0.6}{0.8}=0.25 $ .
