NEETChemistrySolutions
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): For any aqueous solution with a density of exactly 1.0 g/mL , its molality is strictly greater than its molarity. Reason (R): In such a solution, the mass of the solvent is strictly less than 1 kg per Litre of the solution. In the light of the above statements, choose the most appropriate answer fr
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Let us consider 1 L ( 1000 mL ) of an aqueous solution with a density of 1.0 g/mL . Mass of the solution = Volume Density = 1000 mL 1.0 g/mL = 1000 g . We know that: Mass of solution = Mass of solute + Mass of solvent Mass of solvent = 1000 g - Mass of solute Since the mass of the solute must be greater than zero for a solution to exist, the mass of the solvent will be strictly less than 1000 g (or Now, let the number of moles of solute in this 1 L solution be n . Molarity ( M ) = n 1 L = n Molality ( m ) = Moles o