energy

• exothermic - releases heat energy, delta H negative, reactants have higher energy than products
• endothermic - takes in heat, delta H will be positive, products have higher energy than reactants
• enthalpy of combustion - the energy released when 1 mol of a substance burns completely in oxygen
• enthalpy of formation - the energy released when products are formed from reactants at a given temperature
• molar bond enthalpy 


  the energy required to break one mole of bonds in a diatomic molecule
• mean molar bond enthalpy

  the energy required to break one mole of bonds that occur in compounds
• enthalpy change

  bonds BREAKING - bonds MAKING