If a 0.1 m solution is prepared using 0.100 kg of solvent, how many moles of solute are present?
Answer and explanation
Correct answer: 0.01 mol
Molality is defined as moles of solute divided by the mass of solvent in kilograms: m = n/mass of solvent. Rearranging gives n = m × mass of solvent. The solvent mass is already 0.100 kg, so n = 0.1 mol kg⁻¹ × 0.100 kg = 0.010 mol. The mass of the solution is not used in the molality formula. Therefore, option B is correct.
Frequently asked questions
What is the correct answer to this question?
0.01 mol
Why is this the correct answer?
Molality is defined as moles of solute divided by the mass of solvent in kilograms: m = n/mass of solvent. Rearranging gives n = m × mass of solvent. The solvent mass is already 0.100 kg, so n = 0.1 mol kg⁻¹ × 0.100 kg = 0.010 mol. The mass of the solution is not used in the molality formula. Therefore, option B is correct.
Which subject and chapter does this question cover?
This is a Class 12 Chemistry question. Chapter: Chapter 01: Solutions. Topic: 2: Concentration Metrics.
