Which of the following represents the correct units for molality?

• A. g/L
• B. mol/kg
• C. mol/L
• D. mol/mL

Answer: (B)

Verified step by step guidance

1. Understand that molality is a concentration unit that expresses the amount of solute (in moles) per mass of solvent (in kilograms).
2. Recall the definition of molality: \(m = \frac{\text{moles of solute}}{\text{kilograms of solvent}}\).
3. Identify the units involved: moles (mol) for the solute and kilograms (kg) for the solvent.
4. Compare the given options to the definition: molality must have units of mol/kg.
5. Conclude that the correct units for molality are \(\text{mol/kg}\), distinguishing it from molarity which uses volume units like L or mL.