Solutions Question 46
Question: Vapour pressure of a solution of $ 5g $ of non- electrolyte in $ 100g $ of water at a particular temperature is $ 2985,N/m^{2} $ . The vapour pressure of pure water is $ 3000N/m^{2} $ . The molecular weight of the solute is [IIT Screening 1993]
Options:
A) 60
B) 120
C) 180
D) 380
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{P^{o}-P_{s}}{P^{o}}=\frac{\frac{W_2}{M_2}}{\frac{W_1}{M_1}} $ = $ \frac{3000-2985}{3000}=\frac{\frac{5}{M_2}}{\frac{100}{18}}\text{ or }M_2=180 $
