Which of the following units is most appropriate for expressing the heat of solution?

• A. Grams per mole (g/mol)
• B. Atmospheres (atm)
• C. Moles per liter (mol/L)
• D. Joules per mole (J/mol)

Answer: (D)

Verified step by step guidance

1. Understand that the heat of solution refers to the amount of heat absorbed or released when one mole of a substance dissolves in a solvent.
2. Recognize that heat is a form of energy, and energy is typically measured in joules (J) in the SI system.
3. Since the heat of solution is related to the amount of substance dissolved, it is logical to express it per mole, which is the standard unit for amount of substance in chemistry.
4. Evaluate the given units: grams per mole (g/mol) is a unit of molar mass, atmospheres (atm) measure pressure, and moles per liter (mol/L) measure concentration; none of these represent energy per amount of substance.
5. Conclude that the most appropriate unit for heat of solution is joules per mole (J/mol), as it correctly expresses energy change per mole of solute dissolved.