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Chemical change


After this lesson, you should be able to:

  • Explain the concept of enthalpy and its relationship to heat of reaction
  • Define exothermic and endothermic reactions
  • Understand that bond breaking requires energy (endothermic) and bond formation releases energy (exothermic)
  • Classify respiration, photosynthesis and fuel combustion as endothermic or exothermic
  • Explain a reaction process in terms of energy changes related to bond formation and breaking and to “activation complex”
  • Draw graphs of endothermic and exothermic reactions with and without activation energy