1 mole of solute is dissolved in 2 kg of solvent. What is the molality?
Answer and explanation
Correct answer: 0.5 mole per kilogram
Molality is defined as the moles of solute divided by the mass of solvent in kilograms: m = n/mass of solvent. Substitution gives m = 1 mol ÷ 2 kg = 0.5 mol kg⁻¹. Thus, option A is correct. Molarity would require the final solution volume in litres, but this question gives solvent mass, so options B, C and D do not follow the definition.
Frequently asked questions
What is the correct answer to this question?
0.5 mole per kilogram
Why is this the correct answer?
Molality is defined as the moles of solute divided by the mass of solvent in kilograms: m = n/mass of solvent. Substitution gives m = 1 mol ÷ 2 kg = 0.5 mol kg⁻¹. Thus, option A is correct. Molarity would require the final solution volume in litres, but this question gives solvent mass, so options B, C and D do not follow the definition.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
