1. Chapter 7 Chemical Reactions and Quantities
Types of Reactions
Oxidation-Reduction Reactions

2. Type of Reactions
Chemical reactions are classified into four general types
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion

3. Synthesis (Combination)
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

4. Lab Examples: Synthesis
1. 2 Cu(s) + O2(g)  2 CuO (s) 2 2
2. __ Mg(s) + O2(g)  __MgO (s)
Before After
Before After

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

6. Lab Examples: Decomposition1 1 1
3. __CuCO3(s)  __ CuO(s) + ___ (g)
CO2
Before After

7. Learning Check R1 Classify the following reactions as
1) syntheses or 2) decomposition:
___A. H2 + Br HBr
___B. Al2(CO3)3 Al2O3 + 3CO2
___C. 4 Al + 3C Al4C3

8. 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

9. Single Replacement
One element takes the place of an element in a reacting compound.
A + BC AB + C
Mg + 2HCl MgCl H2
Fe CuSO4 FeSO4 + Cu

10. Lab: Single Replacement1 1 Zn 2 1
ZnCl2
4. ___(s) + __ HCl (aq)  _______ (aq) + __ H2 (g)
Before During After

11. Lab: Single Replacement1
FeSO4 1 Cu
5. ____(s) + __ CuSO4 (aq)  _______ (aq) + ___(s) 1 Fe 1
Before During After

12. Double Replacement
Two elements in reactants take the place of each other
AB + CD AD + CB
AgNO3 + NaCl AgCl + NaNO3
ZnS HCl ZnCl2 + H2S

13. Lab: Double Replacement
6. Zn(C2H3O2)2 (aq) + ____ (aq)  NaC2H3O2 (aq) + Zn3(PO4)2 (s) 2
CO2

14. 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

15. 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

16. Combustion
A reaction in which a compound (often carbon) reacts with oxygen
CH4 + 2O2 CO H2O
C3H O2 3CO2 + 4H2O
C6H12O6 + 6O2 6CO2 + 6H2O

17. Demo: Combustion 2 4 3 2 2 – C – 1 4 – H – 2 3 – O – 3
Whoosh in a Bottle
__ CH3OH (l) __ O2 (g) 2 4 3 2
__ CO2 (g) + __ H2O (l)
2 – C – 1
4 – H – 2
3 – O – 3

18. Demo: Combustion

19. Demo: Combustion 6 – C – 1 14 – H – 2 2 – O – 3
Hexene on Ramp
__ C6H14(g) + __ O2 (g) 19 12 2 14
__ CO2 (g) + __ H2O (l)
6 – C – 1
14 – H – 2
2 – O – 3

20. Demo: Combustion

21. Learning Check R3 ___C5H12 + ___O2 ___CO2 + ___H2O
Balance the combustion equation
___C5H ___O ___CO2 + ___H2O