Exothermic Reaction Energy Profile Steps:

• Burning fuel is an exothermic reaction, releasing heat as products (CO2, water) form from reactants.
• Energy profile diagrams plot potential energy vs. reaction progress; exothermic reactions show products at lower energy than reactants.
• The diagram must include an activation energy barrier (energy hump) before energy decreases.
• Select the diagram where overall energy change (ΔH) is negative, indicating heat release.

Why C is correct:

• C depicts reactants higher than products with an activation energy peak, matching the definition of an exothermic reaction (ΔH < 0).

Why the others are wrong:

• A shows products higher than reactants, indicating endothermic absorption of energy.
• B lacks an activation energy barrier, violating transition state theory.
• D shows flat or increasing energy, not representing net energy release.

Final answer: C