Types of Chemical Reactions

1. Types of Chemical Reactions Aim CE2: What are the five general types of chemical reactions?

2. Types of Chemical Reactions • There are many different types of chemical reactions, but most are base on one of the five that follow • Combustion Reactions • A hydrocarbon (a compound with H and C) reacts with oxygen to produce CO2 and H2O • General equation: CxHy + O2 CO2 + H2O • Examples CH4 + 2 O2 CO2 + 2H2O C3H8 + 5 O2 3CO2 + 4H2O

3. Synthesis the formation of a new compound General equation: A + B  AB Examples 2 Na + Cl2  2 NaCl two sodiums combine with two chlorines to make 2 sodium chlorides 2 H2 + O2 2 H2O two hydrogen diatomic molecules combine with two diatomic oxygen molecules to form two water molecules

4. Decomposition the breakdown of one compound into several smaller compounds or elements General equation: AB  A + B Examples 2 NaCl  2 Na + Cl2 two sodium chlorides breakdown into sodium and chlorine elements 2 H2O2 O2 + 2 H2O two hydrogen peroxides break down into one oxygen molecule and two water molecules

5. Single replacement reaction • One element switches places with an element in an existing compound • General equation: AB + C  AC + B • Examples Mg + CuCl2 MgCl2 + Cu Magnesium switches positions with copper 3 Mg + Al2O3  3 MgO + 2 Al Aluminum switches positions with magnesium

6. Double replacement reaction Two elements switch partners with each other in two different compounds General equation: AB + CD  AD + CB Examples AlCl3 + LiBr  LiCl + AlBr3 Aluminum and lithium switch partners CuSO4 + PbI2 CuI2 + PbSO4 copper and lead switch partners