Chapter summary
Chemical Energetics, at a glance
Explain temperature changes and the energy cost of rearranging particles.
O-Level 6092 (2026) / SEC G3 K324 (2027)
Quick revision
Revisit the essentials, then return to an explanation when you need it.
Exothermic: energy out to surroundings. Endothermic: energy in from surroundings. Use the initial change and account for later heat exchange.
Pure only
Pure: ΔH compares product and reactant levels; Ea is the barrier. Breaking bonds absorbs energy; making bonds releases it. Compare both totals.