1. Chapter 5 Chemical Reactions and Quantities
5.3
Types of Reactions
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

2. Type of Reactions Chemical reactions can be classified as
combination reactions.
decomposition reactions.
single replacement reactions.
double replacement reactions.

3. Combination In a combination reaction,
two or more elements form one product.
or simple compounds combine to form one product. +
2Mg(s) + O2(g) 2MgO(s)
2Na(s) + Cl2(g) 2NaCl(s)
SO3(g) + H2O(l) H2SO4(aq) A B

4. Formation of MgO

5. Decomposition In a decomposition reaction,
one substance splits into two or more simpler substances.
2HgO(s) Hg(l) + O2(g)
2KClO3(s) KCl(s) + 3 O2(g)

6. Decomposition of HgO

7. Learning Check Classify the following reactions as
1) combination or 2) decomposition.
___A. H2(g) + Br2(g) HBr(l)
___B. Al2(CO3)3(s) Al2O3(s) + 3CO2(g)
___C. 4Al(s) + 3C(s) Al4C3(s)

8. Solution Classify the following reactions as
1) combination or 2) decomposition:
1 A. H2(g) + Br2(g) HBr(l)
2 B. Al2(CO3)3(s) Al2O3(s) + 3CO2(g)
1 C. 4Al(s) + 3C(s) Al4C3(s)

9. Single Replacement In a single replacement reaction,
one element takes the place of a different element in a reacting compound.
Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g)
Fe(s) + CuSO4(aq) FeSO4(aq) + Cu(s)

10. Zn and HCl is a Single Replacement Reaction

11. Double Replacement In a double replacement,
two elements in the reactants exchange places.
AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq)
ZnS(s) HCl(aq) ZnCl2(aq) + H2S(g)

12. Example of a Double Replacement

13. Learning Check Classify the following reactions as
1) single replacement 2) double replacement.
__A. 2Al(s) + 3H2SO4(aq) Al2(SO4)3(s) + 3H2(g)
__B. Na2SO4(aq) + 2AgNO3(aq) Ag2SO4(s) + 2NaNO3(aq)
__C. 3C(s) + Fe2O3(s) Fe(s) CO(g)

14. Solution Classify the following reactions as
1) single replacement 2) double replacement
1 A. 2Al(s) + 3H2SO4(aq) Al2(SO4)3(s) H2(g)
2 B. Na2SO4(aq) + 2AgNO3(aq) Ag2SO4(s) + 2NaNO3(aq)
1 C. 3C(s) + Fe2O3(s) Fe(s) CO(g)

15. Learning Check Identify each reaction as
1) combination 2) decomposition
3) single replacement 4) double replacement
A. 3Ba(s) + N2(g) Ba3N2(s)
B. 2Ag(s) + H2S(aq) Ag2S(s) + H2(g)
C. SiO2(s) + 4HF(aq) SiF4(s) + 2H2O(l)
D. PbCl2(aq) + K2SO4(aq) KCl(aq) + PbSO4(s)
E. K2CO3(s) K2O(aq) + CO2(g)

16. Solution 1 A. 3Ba(s) + N2(g) Ba3N2(s)
3 B. 2Ag(s) + H2S(aq) Ag2S(s) + H2(g)
4 C. SiO2(s) + 4HF(aq) SiF4(s) + 2H2O(l)
4 D. PbCl2(aq) + K2SO4(aq) KCl(aq) +PbSO4(s)
2 E. K2CO3(s) K2O(aq) + CO2(g)