Q. A 5% solution of sugarcane (mol. wt. = 342) is isotonic with 1% solution of X under similar conditions. The molecular weight of X is
A) 136.2
B) 689.4
C) 34.2
D) 171.2
Explanation
(b)
For isotonic solutions,
$\frac{w_{1}}{m_{1}} = \frac{w_{2}}{m_{2}} \Rightarrow \frac{5}{342} = \frac{1}{m_{2}} \Rightarrow m_{2} = \frac{342}{5} = 68.4$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.