JEE Main & Advanced Chemistry Some Basic Concepts of Chemistry / रसायन की कुछ मूलभूत अवधारणाएँ Question Bank Self Evaluation Test - Some Basic Concepts of Chemistry

The density of 3M solution of sodium chloride is \[1.252g\text{ }m{{L}^{-1}}\]. The molality of the solution will be (molar mass,\[NaCl=585gmo{{l}^{-1}}\])

A) 2.60 m

B) 2.18 m

C) 2.79 m

D) 3.00 m

Correct Answer: C

Solution :

[c] The relation between molarity (M) and molality (m) is \[d=M\left( \frac{1}{m}+\frac{{{M}_{2}}}{1000} \right).\]

\[{{M}_{2}}\]= Mol. mass of solute

On putting value \[1.252=3\left( \frac{1}{m}+\frac{58.8}{1000} \right)\] on solving m= 2.79