1. Chemical Reactions

2. Energy of Chemical Reactions

3.  When chemical reactions occur there is always a change in Energy.  Two types of Energy change. 1. Exothermic Reaction  Give off heat. (Heat Energy is a product)  Ex: C12H22O11 12C + 11H2O + Energy 2. Endothermic Reaction  Takes in Energy, Energy is absorbed (heat is a reactant).  Ex: 2NaCl + E 2Na + Cl 2

4.  The energy required to get a reaction going.  Exothermic Reaction- Energy of reactants is greater than Energy of the products.

5.  The energy required to get a reaction going.  Endothermic Reaction- Energy of reactants is less than Energy of the products.

6.  A reaction will occur only if the reactants can get over the activation Energy.  Ex: If you don’t strike a match hard enough, it won’t light because it doesn’t have enough E to get over the hill.