Solutions Question 2
Question: Vapour pressure of $ CCl_4 $ at $ 25^{o}C $ is $ 143mm $ of $ Hg 0.5 gm $ of a non-volatile solute (mol. wt. = 65) is dissolved in $ 100 ml CCl_4 $ . Find the vapour pressure of the solution (Density of $ CCl_4=1.58 g/cm^{2} $ ) [CBSE PMT 1998]
Options:
A) $ 141.97 $ mm Hg
B) $ 94.39 $ mm Hg
C) $ 199.34 $ mm Hg
D) $ 143.99 $ mm Hg
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{P^{0}-Ps}{P^{0}}=\frac{w\times M}{mW} $
$ =143-\frac{0.5\times 154}{65\times 158}\times 143 $
$ =143-1.03=141.97 mm Hg$ .