Solutions Question 86
Question: If $ 0.15,g $ of a solute dissolved in $ 15,g $ of solvent is boiled at a temperature higher by $ {{0.216}^{o}}C $ than that of the pure solvent. The molecular weight of the substance (molal elevation constant for the solvent is $ {{2.16}^{o}}C $ ) is [CBSE PMT 1999; BHU 1997]
Options:
A) 1.01
B) 10
C) 10.1
D) 100
Show Answer
Answer:
Correct Answer: D
Solution:
$ m=\frac{K_{b}\times w\times 1000}{\Delta T_{b}\times W}=\frac{2.16\times 0.15\times 1000}{0.216\times 15} $ = 100 .