Chem Chap 7

• Exothermic reaction

  • Produces heat energy
  • Energy from bond breaking > Needed amount to break
  • Temp difference always negative
• Endothermic reaction

  • Absorbs heat energy
  • Energy from bond breaking > Amount from bond forming
  • Temp diff always positive
• Bond energy

  • Amount of energy it takes to make/break bonds
  • Each bond is unique
  • Make & break uses same amount
• Endo & Exo 'graphs'

  • Endo: reactants lower than products
  • Exo: reactants higher than products
• Steps to take

  1. Figure out the bonds (draw if needed)
  2. Add up total bond energy (1 reactants & 1 products)
  3. Reactants - products (total bond energy)
  4. Positive = endo, negative = exo
  5. Draw 'graph' accordingly