The units commonly used for molar enthalpy are which?

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Multiple Choice

The units commonly used for molar enthalpy are which?

Molar enthalpy is the heat content per amount of substance, so its units must express energy per mole. That’s why J/mol or kJ/mol are used. They show how much energy corresponds to one mole of material. If you had 2 moles with a molar enthalpy of 40 kJ/mol, the total enthalpy change would be 80 kJ, illustrating why the per-mole form is important. Using J or kJ alone would give energy without tying it to how much substance is present, and J/kg would be energy per mass, not per mole, which is a different quantity (specific enthalpy).

Molar enthalpy is the heat content per amount of substance, so its units must express energy per mole. That’s why J/mol or kJ/mol are used. They show how much energy corresponds to one mole of material. If you had 2 moles with a molar enthalpy of 40 kJ/mol, the total enthalpy change would be 80 kJ, illustrating why the per-mole form is important. Using J or kJ alone would give energy without tying it to how much substance is present, and J/kg would be energy per mass, not per mole, which is a different quantity (specific enthalpy).

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