Molality of a solution is defined as the number of moles of solute per:
Alitre of solvent
Blitre of solution
Ckilogram of solution
Dkilogram of solvent
Answer & Solution
Correct answer: D. kilogram of solvent
1. Molality (m) = moles of solute / mass of solvent in kg.
2. Molarity uses volume of solution in litres, so option A describes molarity, not molality.
3. The defining mass is that of the solvent (not the solution), so molality is moles of solute per kilogram of solvent.
_Source: NCERT Class 12 Chemistry Ch 1 "Solutions", p.4_
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