1 Chapter 7 Chemical Reactions 7.4 Types of Reactions Copyright © 2008 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. Combustion reactions.

3 Combination In a combination reaction, Two or more elements form one product. Or simple compounds combine to form one product. + 2Mg(s) + O 2 (g) 2MgO(s) 2Na(s) + Cl 2 (g)2NaCl(s) SO 3 (g) + H 2 O(l)H 2 SO 4 (aq) AB AB

4 Formation of MgO (see demo) Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

5 Decomposition (Elephant toothpaste demo) In a decomposition reaction, One substance splits into two or more simpler substances. 2HgO(s) 2Hg(l) + O 2 (g) 2KClO 3 (s) 2KCl(s) + 3O 2 (g) 1 H 2 O 2 (aq) KI (aq) 1 H 2 (g) + 1 O 2 (g) Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

6 Decomposition of HgO Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

7 Learning Check Classify the following reactions as 1) combination or 2) decomposition: ___A. H 2 (g) + Br 2 (g) 2HBr(l) ___B. Al 2 (CO 3 ) 3 (s) Al 2 O 3 (s) + 3CO 2 (g) ___C. 4Al(s) + 3C(s) Al 4 C 3 (s)

8 Solution Classify the following reactions as 1) combination or 2) decomposition: 1 A. H 2 (g) + Br 2 (g) 2HBr(l) 2 B. Al 2 (CO 3 ) 3 (s) Al 2 O 3 (s) + 3CO 2 (g) 1 C. 4Al(s) + 3C(s) Al 4 C 3 (s)

9 Single Replacement (demo) In a single replacement reaction, One element takes the place of a different element in a reacting compound. Zn(s) + 2HCl(aq) ZnCl 2 (aq) + H 2 (g) Fe(s) + CuSO 4 (aq)FeSO 4 (aq) + Cu(s) Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

10 Zn and HCl is a Single Replacement Reaction Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

11 Double Replacement (demo lead nitrate and KI) In a double replacement reaction, Two elements in the reactants exchange places. AgNO 3 (aq) + NaCl(aq)AgCl(s) + NaNO 3 (aq) ZnS(s) + 2HCl(aq)ZnCl 2 (aq) + H 2 S(g) Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

12 Example of a Double Replacement Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

13 Learning Check Classify the following reactions as 1) single replacement 2) double replacement __A. 2Al(s) + 3H 2 SO 4 (aq) Al 2 (SO 4 ) 3 (s) + 3H 2 (g) __B. Na 2 SO 4 (aq) + 2AgNO 3 (aq) Ag 2 SO 4 (s) + 2NaNO 3 (aq) __C. 3C(s) + Fe 2 O 3 (s) 2Fe(s) + 3CO(g)

14 Solution Classify the following reactions as 1) single replacement 2) double replacement 1 A. 2Al(s) + 3H 2 SO 4 (aq) Al 2 (SO 4 ) 3 (s) + 3H 2 (g) 2 B. Na 2 SO 4 (aq) + 2AgNO 3 (aq) Ag 2 SO 4 (s) + 2NaNO 3 (aq) 1 C. 3C(s) + Fe 2 O 3 (s) 2Fe(s) + 3CO(g)

15 In a combustion reaction, A compound such as carbon reacts with oxygen, O 2. C(s) + O 2 (g)CO 2 (g) CH 4 (g) + 2O 2 (g) CO 2 (g) + 2H 2 O(g) C 3 H 8 (g) + 5O 2 (g) 3CO 2 (g) + 4H 2 O(g) Fuels burned in oxygen produce CO 2, H 2 O, and energy. Combustion (demo bunsen burner)

16 Example of a Combustion Reaction Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings

17 Learning Check Balance the combustion equation ___C 5 H 12 + ___O 2 ___CO 2 + ___H 2 O

18 Solution Balance the combustion equation 1 C 5 H O 2 5 CO H 2 O

19 Summary of Reaction Types Copyright © 2008 by Pearson Education, Inc. Publishing as Benjamin Cummings Table 7.4

20 Learning Check Identify each reaction as: 1) combination 2) decomposition 3) combustion 4) single replacement5) double replacement A. 3Ba(s) + N 2 (g) Ba 3 N 2 (s) B. 2Ag(s) + H 2 S(aq) Ag 2 S(s) + H 2 (g) C. SiO 2 (s) + 4HF(aq) SiF 4 (s) + 2H 2 O(l) D. PbCl 2 (aq) + K 2 SO 4 (aq) 2KCl(aq) + PbSO 4 (s) E. K 2 CO 3 (s) K 2 O(aq) + CO 2 (g) F. C 2 H 4 (g) + 3O 2 (g) 2CO 2 (g) + 2H 2 O(g)

21 Solution Identify each reaction as: 1) combination 2) decomposition 3) combustion 4) single replacement5) double replacement 1 A. 3Ba(s) + N 2 (g) Ba 3 N 2 (s) 4 B. 2Ag(s) + H 2 S(aq) Ag 2 S(s) + H 2 (g) 5 C. SiO 2 (s) + 4HF(aq) SiF 4 (s) + 2H 2 O(l) 5 D. PbCl 2 (aq) + K 2 SO 4 (aq) 2KCl(aq) + PbSO 4 (s) 2 E. K 2 CO 3 (s) K 2 O(aq) + CO 2 (g) 3 F. C 2 H 4 (g) + 3O 2 (g) 2CO 2 (g) + 2H 2 O(g)