Solutions Question 275
Question: A 5% solution of canesugar (mol. wt. =342) is isotonic with 1% solution of a substance $ X $ . The molecular weight of $ X $ is [CBSE PMT 1998]
Options:
A) 34.2
B) 171.2
C) 68.4
D) 136.8
Show Answer
Answer:
Correct Answer: C
Solution:
Molar concentration of cane sugar $ =\frac{5}{342}\times \frac{1000}{100}=\frac{50}{342} $ Molar concentration of X = $ \frac{1}{m}\times \frac{1000}{100}=\frac{10}{m} $
$ \frac{10}{m}=\frac{50}{342} $ or $ m=68.4 $ .
