For which one of the following reactions is the value of ΔH°_rxn equal to ΔH°_f for the product? A)2Ca (s) + O₂ (g) → 2CaO (s) B)C₂H₂ (g) + H₂ (g) → C₂H₄ (g) C)2C (graphite) + O₂ (g) → 2CO (g) D)3Mg (s) + N₂ (g) → Mg₃N₂ (s) E)C (diamond) + O₂ (g) → CO₂ (g)

Question

Quizplus · Accepted Answer

The standard enthalpy of formation (ΔH°_f) is defined for the formation of 1 mole of a compound from its elements in their standard states. In reaction D, 1 mole of Mg₃N₂ is formed from its elements, magnesium and nitrogen, in their standard states.

For Which One of the Following Reactions Is the Value