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

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

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

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

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

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

Learning Check R1 Classify the following reactions as 1) syntheses or 2) decomposition: ___A. H2 + Br2 2HBr ___B. Al2(CO3)3 Al2O3 + 3CO2 ___C. 4 Al + 3C Al4C3

Solution R1 Classify the following reactions as 1) combination or 2) decomposition: _1_A. H2 + Br2 2HBr _2_B. Al2(CO3)3 Al2O3 + 3CO2 _1_C. 4 Al + 3C Al4C3

Single Replacement One element takes the place of an element in a reacting compound. A + BC AB + C Mg + 2HCl MgCl2 + H2 Fe + CuSO4 FeSO4 + Cu

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

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

Double Replacement Two elements in reactants take the place of each other AB + CD AD + CB AgNO3 + NaCl AgCl + NaNO3 ZnS + 2HCl ZnCl2 + H2S

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

Learning Check R2 Classify the following reactions as 1) single replacement 2) double replacement __A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2 __B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3 __C. 3C + Fe2O3 2Fe + 3CO

Solution R2 Classify the following reactions as 1) single replacement 2) double replacement 1_A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2 2_B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3 1_C. 3C + Fe2O3 2Fe + 3CO

Combustion A reaction in which a compound (often carbon) reacts with oxygen CH4 + 2O2 CO2 + 2H2O C3H8 + 5O2 3CO2 + 4H2O C6H12O6 + 6O2 6CO2 + 6H2O

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

Demo: Combustion

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

Demo: Combustion

Learning Check R3 ___C5H12 + ___O2 ___CO2 + ___H2O Balance the combustion equation ___C5H12 + ___O2 ___CO2 + ___H2O