In the reaction, C + O2 → CO2; ΔH = - 94 kcal. What is the heat content (enthalpy) of O2 ?
Correct answer: D. Zero
- A. -94 kcal
- B. > -94 kcal
- C. < - 94 kcal
- D. Zero
Explanation
Oxygen is an element in its standard reference state, so its standard enthalpy of formation is defined as zero. The −94 kcal value is the reaction enthalpy for forming CO₂, not the enthalpy of O₂.
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