10% of solution of urea is isotonic with 6% solution of a no... | CHEMISTRY - COLLIGATIVE PROPERTIES AND DETERMINATION OF MOLAR MASS | SolveeIt | Solveeit

Today, August 18

Question

10% of solution of urea is isotonic with 6% solution of a non volatile solute X. what is the molecular mass of solute X?

A

$6gmol^{- 1}$

B

$60gmol^{- 1}$

C

$36gmol^{- 1}$

D

$32gmol^{- 1}$

Answer

$36gmol^{- 1}$

Explanation

Solution

No. of mole of urea $= \frac{10}{60} = \frac{1}{6}$

Weight of solute, $X = 6g$

No. of moles of $X = \frac{6}{M}$

For isotonic solution $n_{1} = n_{2}$

Or $\frac{1}{6} = \frac{6}{M}$ or $M = 36gmol^{- 1}$