1. Types of Reactions You need to be able to identify each type.
Synthesis reactions
Decomposition reactions
Single displacement reactions
Double displacement reactions
Combustion reactions
You need to be able to identify each type.

2. 1. Synthesis
Example C + O2 O C +  O C
General: A + B  AB

3. Combination (Synthesis)
Two or more elements or simple compounds combine to form (synthesize) one product
A + B AB
2Mg + O2 2MgO
2Na + Cl2 2NaCl
SO3 + H2O H2SO4
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4. Ex. Synthesis Reaction

5. Practice Predict the products. Na(s) + Cl2(g)  Mg(s) + F2(g) 
Al(s) + F2(g)  2 2
NaCl(s)
MgF2(s) 2 3 2
AlF3(s)
Now, balance them.

6. 2. Decomposition
Example: NaCl  Cl Na Cl + Na
General: AB  A + B

7. Ex. Decomposition Reaction

8. LecturePLUS Timberlake 99
Decomposition
One substance is broken down (split) into two or more simpler substances.
AB A + B
2HgO 2Hg + O2
2KClO3 2KCl + 3 O2
LecturePLUS Timberlake 99

9. LecturePLUS Timberlake 99
Learning Check R1
Classify the following reactions as
1) combination or 2) decomposition:
___A. H2 + Br HBr
___B. Al2(CO3)3 Al2O3 + 3CO2
___C. 4 Al + 3C Al4C3
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10. LecturePLUS Timberlake 99
Solution R1
Classify the following reactions as
1) combination or 2) decomposition:
_1_A. H2 + Br HBr
_2_B. Al2(CO3)3 Al2O3 + 3CO2
_1_C. 4 Al + 3C Al4C3
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11. Went from neutral (0) to (+2) Went from (+2) to Neutral (0)
3. Single Displacement
Example: Zn + CuCl2
Zn was oxidized
Went from neutral (0) to (+2)  Zn Cl Cu + Cl Zn Cu +
Cu was reduced
Went from (+2) to Neutral (0)
General: AB + C  AC + B

12. LecturePLUS Timberlake 99
Single Replacement
One element takes the place of an element in a reacting compound.
A + BC AB + C
Zn + 2HCl ZnCl H2
Fe CuSO4 FeSO4 + Cu
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13. Ex. Single Replacement Reaction

14. Single Replacement Reactions
Write and balance the following single replacement reaction equation:
Zn(s) HCl(aq)  ZnCl2 + H2(g) 2
NaCl(s) + F2(g)  NaF(s) + Cl2(g)
Al(s)+ Cu(NO3)2(aq) 2 2 2 3 3
Cu(s)+ Al(NO3)3(aq) 2

15. 4. Double displacement General: AB + CD  AD + CB Example: MgO + CaS 

16. LecturePLUS Timberlake 99
Double Replacement
Two elements in reactants take the place of each other
AB + CD AD + CB
AgNO3 + NaCl AgCl + NaNO3
ZnS HCl ZnCl2 + H2S
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17. Double Replacement Reactions
Think about it like “foil”ing in algebra, first and last ions go together + inside ions go together
Example:
AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq)
Another example:
K2SO4(aq) + Ba(NO3)2(aq)  KNO3(aq) + BaSO4(s) 2

18. LecturePLUS Timberlake 99
Learning Check R2
Classify the following reactions as
1) single replacement
2) double replacement
__A. 2Al + 3H2SO Al2(SO4) H2
__B. Na2SO4 + 2AgNO Ag2SO4 + 2NaNO3
__C. 3C + Fe2O Fe CO
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19. LecturePLUS Timberlake 99
Solution R2
Classify the following reactions as
1) single replacement
2) double replacement
1_A. 2Al + 3H2SO Al2(SO4) H2
2_B. Na2SO4 + 2AgNO Ag2SO4 + 2NaNO3
1_C. 3C + Fe2O Fe CO
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20. Practice Predict the products. HCl(aq) + AgNO3(aq) 
CaCl2(aq) + Na3PO4(aq) 
Pb(NO3)2(aq) + BaCl2(aq) 
FeCl3(aq) + NaOH(aq) 
H2SO4(aq) + NaOH(aq) 
KOH(aq) + CuSO4(aq) 

21. 5. Combustion Reactions
Combustion reactions - a hydrocarbon reacts with oxygen gas.
This is also called burning!!!
In order to burn something you need the 3 things in the “fire triangle”:
1) Fuel (hydrocarbon) 2) Oxygen 3) Something to ignite the reaction (spark)

22. Combustion Reactions In general: CxHy + O2  CO2 + H2O
Products are ALWAYS
carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide)
Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C8H18)

23. LecturePLUS Timberlake 99
Combustion
A reaction in which a compound (often carbon) reacts with oxygen
C + O2 CO2
CH4 + 2O2 CO H2O
C3H O2 3CO2 + 4H2O
C6H12O6 + 6O2 6CO2 + 6H2O
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24. Combustion
Example
C5H O2  CO2 + H2O
Write the products and balance the following combustion reaction:
C10H O2  8 5 6

25. LecturePLUS Timberlake 99
Learning Check R3
Balance the combustion equation
___C5H ___O ___CO2 + ___H2O
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26. LecturePLUS Timberlake 99
Solution R3
Balance the combustion equation
1 C5H O CO H2O
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