1. Types of chemical reactions
Lesson 12

2. Types of chemical reactions
1. Combustion Reaction
The reaction of a substance with oxygen, producing oxides and energy
Fuel + oxygen  oxides + energy
AB + oxygen  common oxides of A and B (ex AO, BO)

3. Common oxides include
C = CO2(g)
H = H2O(g)
S = SO2(g)
N =NO2(g)

4. Example
2C3H6 (g) + 9O2(g)  6CO2(g) + 6H2O(g)

5. Incomplete combustion occurs when there is not sufficient oxygen
Incomplete combustion occurs when there is not sufficient oxygen. When this occurs 4 products are produced instead of the usual H2O and CO2. Incomplete combustion also produces CO(g) and C(s). This is commonly seen when lighting an acetylene torch.
3C2H2­(g) + 3O2(g)  2CO2(g) + 3H2­O(g) + 2CO(g) + 2C(s)

6. 2. Synthesis Reaction
-A chemical reaction in which two or more substances combine to form a more complex substance.
A + B  AB
Example:
2CO(g) O2(g) pt 2CO2(g)

7. 3. Decomposition reaction
-A chemical reaction in which a compound is broken down into two or more simpler substances.
AB  A B
Example: The decomposition of water.
2H2O(l) + electricity 2 H2(g) + O2(g)

8. Chemical reactions in solution
A Solution is a homogenous mixture in which a pure substance, called the solute, is dissolved in another pure substance called the solvent.
The solution is often an aqueous solution which is a solution where water is the solvent.

9. 4. Single Displacement reaction
-A reaction of an element with a compound to produce a new element and a new compound. The reaction will only occur if the element is higher on the reactivity series than the metal in the compound.
A + BC  AC + B
Example:
Cu(s) + 2AgNO3(aq)  2Ag(s) + Cu(NO3)2(aq)

11. 5. Double displacement reaction
- A reaction in which aqueous ionic compounds rearrange cations and anions, resulting in the formation of new compounds.
AB + CD  AD + CB
Example:
Pb(NO3)2 (aq) + 2KI (aq)  PbI2 (s) + 2KNO3 (aq)

12. Double displacement is likely to occur if;
- a precipitate is produced
- a gas is produced
- a acid base neutralization occurs

13. Examples 2As + 3O2  2As2O3 KClO4  KCl + 2O2
Type of reaction?
KClO4  KCl + 2O2
Zn(s) + CuCl2(s)  Will it occur? Look at the table.

14. Cu(s) + ZnCl2(s) 
will it occur
MgCl2(aq) + Ca(OH)2(aq) 