1. Chapter 6 – 2 Warm - Up 1. What is a chemical reaction?
2. What is one sign that a chemical reaction has taken place?
3. What is the difference between an exothermic and an endothermic reaction?
4. What idea did Antoine Lavoisier come up with?

2. Chapter 6 – 2 Chemical Reactions
Types of Reactions

3. Types of Reactions
Chemists have defined 6 types of chemical reactions:
Combustion
Synthesis
Decomposition
Single displacement
Double displacement
Oxidation-Reduction Reaction

4. Synthesis Reactions
Synthesis reaction - two or more substances combine to form another substance.
A + B  AB
2 Na + Cl2  2 NaCl

5. Synthesis Reactions
Metal sodium reacts with chlorine gas for form sodium chloride
Table Salt
2Na + Cl2  2NaCl

6. Synthesis Reactions
Glucose and oxygen gas form carbon dioxide and water
Photosynthesis
6CO2 + 6H2O  C6H12O6 + 6O2

7. Decomposition Reactions
Decomposition reaction - one substance breaks down, or decomposes, into two or more substances
Reverse of a synthesis reaction
AB  A + B
2H20  2H2 + 02
Most require the use of heat, light, or electricity

8. Decomposition Reactions
Digestion
Electrolysis – process where an electric current is used to produce a chemical reaction
Metals resistant to corrosion
Production of oxygen in subs
Metal decoration
Hair removal
2H2O  2H2 + O2

9. Combustion Reactions
Combustion reaction - a substance reacts with oxygen to produce energy in the form of heat and light.
Something burning
Heat is released

12. Single Displacement
Single-displacement reaction - One element replaces another element in a compound
A + BC  AC + B
2Al + 3CuCl2  2AlCl3 + 3Cu

13. Single Displacement
Aluminum undergoes a single-displacement reaction with copper (II) chloride to form copper and aluminum chloride
3CuCl2 + 2Al  2AlCl3 + 3Cu

14. Single Displacement
Potassium reacts with water in a single replacement reaction to form potassium hydroxide and hydrogen
K + H2O  KOH + H2

15. Double Displacement
Double displacement - a precipitate, water, or a gas forms when two compounds in solution are combined
AB + CD  AD + CB
Pb(N03)2 + K2CrO4  PbCrO4 + 2KNO3

16. Oxidation-Reduction Reaction
Oxidation-Reduction Reaction – chemical change where one part is oxidized (loses electron) and another part is reduced (gains electron)
Redox Reaction

17. Oxidation-Reduction Reaction
Respiration
Combustion

18. Radials
Radical – an organic group that has one or more electrons available for bonding
Used to make polystyrene foam or insulation