1. Chapter 5 Chemical Quantities and Reactions
5.5
Types of Reactions

2. Homework due for Wed
Red problems in blue box at end of section 5.5, classifying reactions

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

4. 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

5. Formation of MgO
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6. 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)

7. Decomposition of HgO
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8. 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)

9. 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)

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

11. Zn and HCl is a Single Replacement Reaction
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12. 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)

13. Example of a Double Replacement
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14. Learning Check Classify the following reactions as
1) single replacement or 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)

15. Solution Classify the following reactions as
1) single replacement or 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)

16. Learning Check
Identify each reaction as 1) combination, 2) decomposition,
3) single replacement, or 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)

17. 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)

18. Learning Check
Each of the following reactions occur in the formation of
smog or acid rain. Identify the type of reaction and
balance each.
A. NO(g) + O2(g) NO2(s)
B. N2(g) + O2(g) NO(g)
C. SO2(g) + O2(g) SO3(g)
D. NO2(g) NO(g) + O(g)

19. Solution Each of the following reactions occur in the formation of
smog or acid rain. Identify the type of reaction and
balance each.
Combination
A. 2NO(g) + O2(g) NO2(s)
B. N2(g) + O2(g) 2NO(g)
C. 2SO2(g) + O2(g) SO3(g)
Decomposition
D. NO2(g) NO(g) + O(g)

20. Websites for more practice
Then use extra practice worksheet PRA020 on MS word

21. Classwork for
Lab to view types of reactions, then lesson to try to predict products Fun with predicting reaction products worksheets