Exothermic reaction energy profile for CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(ℓ) + 890.4 kJ.
Energy diagram showing potential energy vs. reaction coordinate for the combustion of methane, with labeled activation energy (A), transition state (B), enthalpy change (C), and products (D), and energy released (E).