1. 14.2 Energy and Chemical Reactions
Energy is in chemical reactions in two ways:
to break some (or all) chemical bonds between atoms in the
To form new chemical bonds to make new

2. Two Types of Energy Transfers
We classify chemical reactions based on how the energy is transferred between the
– Heat is by the reactants during the reaction (“In”). Examples
– Heat is by the reactants during the reaction (“Exit”). Examples

3. Energy is also Transferred in Physical Changes (recall phase changes) Exothermic:
Endothermic: