Bond energy calculation — methane combustion (6-mark)

GCSE · Combined Science · CCEA · C2.3 — Energy changes: exothermic vs endothermic, reaction profiles, bond-energy calculations

Question

CH₄ + 2O₂ → CO₂ + 2H₂O

Bond energies (kJ/mol): C−H = 413; O=O = 498; C=O = 805; O−H = 463

(a) Calculate total energy to break bonds in reactants. (3 marks) (b) Calculate total energy released forming bonds in products. (3 marks) (c) Calculate the overall energy change and state whether the reaction is exothermic or endothermic. (2 marks)

8 marks · take your time before peeking.

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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.