1. Types of Chemical Reactions

2. Synthesis
A + B  AB P4 + O2  P4O2 2 or more elements combine to make a more complex substance

3. Compounds break down into simpler substances.
Decomposition
AB  A + B
2H20  2H20 + O2
Compounds break down into simpler substances.

4. One element replaces another element in a compound.
Single Displacement
AB + C  A + BC
2Cu2O + C  4Cu + CO2
One element replaces another element in a compound.

5. Double Displacement
AB + CD  AC + BD
PbBr2 + 2HCl  2HBr + PbCl2
Elements in one compound trade places with elements in another compound.

6. Combustion
C2H O2  2CO H2O
Oxygen combines with another compound to form water and carbon dioxide.