NEET Chemistry Some Basic Concepts of Chemistry / रसायन की कुछ मूलभूत अवधारणाएँ NEET PYQ-Some Basic Concepts Chemistry

The mole fraction of the solute in one molal aqueous solution is:                                           [AIPMT (S) 2005]

A) 0.027

B)      0.036

C) 0.018

D) 0.009

Correct Answer: C

Solution :

Molality of solution = Mole of solute per kg of solvent

So 1 m = 1 mole of solute per 1000 g of solvent

Hence, moles of solute in 1 m aqueous solvent = 1

moles of solvent in 1 m aqueous solution

\[=\frac{1000}{18}=55.55\]

Mole fraction of solute in 1 m solution

\[=\frac{1}{1+55.55}=\frac{1}{56.55}=0.0176\approx 0.018\]