Dr Seemal Jelani Chem-100 Chemical Reactions and Quantities Types of Reactions Oxidation-Reduction Reactions 12/16/20151

Dr Seemal Jelani Chem-100 Type of Reactions Chemical reactions are classified into four general types Combination Decomposition Single Replacement Double Replacement 12/16/20152

Dr Seemal Jelani Chem-100 Combination (Synthesis) Two or more elements or simple compounds combine to form (synthesize) one product A + B AB 2Mg + O 2 2MgO 2Na + Cl 2 2NaCl SO 3 + H 2 OH 2 SO 4 12/16/20153

Dr Seemal Jelani Chem-100 Decomposition One substance is broken down (split) into two or more simpler substances. ABA + B 2HgO2Hg + O 2 2KClO 3 2KCl + 3 O 2 12/16/20154

Dr Seemal Jelani Chem-100 Learning Check R1 Classify the following reactions as 1) combination or 2) decomposition: ___A. H 2 + Br 2 2HBr ___B. Al 2 (CO 3 ) 3 Al 2 O 3 + 3CO 2 ___C. 4 Al + 3C Al 4 C 3 12/16/20155

Dr Seemal Jelani Chem-100 Solution R1 Classify the following reactions as 1) combination or 2) decomposition: _1_A. H 2 + Br 2 2HBr _2_B. Al 2 (CO 3 ) 3 Al 2 O 3 + 3CO 2 _1_C. 4 Al + 3C Al 4 C 3 12/16/20156

Dr Seemal Jelani Chem-100 Single Replacement One element takes the place of an element in a reacting compound. A + BC AB + C Zn + 2HCl ZnCl 2 + H 2 Fe + CuSO 4 FeSO 4 +Cu 12/16/20157

Dr Seemal Jelani Chem-100 Double Replacement Two elements in reactants take the place of each other AB + CD AD + CB AgNO 3 + NaCl AgCl + NaNO 3 ZnS + 2HCl ZnCl 2 +H 2 S 12/16/20158

Dr Seemal Jelani Chem-100 Learning Check R2 Classify the following reactions as 1) single replacement 2) double replacement __ A. 2Al + 3H 2 SO 4 Al 2 (SO 4 ) 3 + 3H 2 __B. Na 2 SO 4 + 2AgNO 3 Ag 2 SO 4 + 2NaNO 3 __C. 3C + Fe 2 O 3 2Fe + 3CO 12/16/20159

Dr Seemal Jelani Chem-100 Solution R2 Classify the following reactions as 1) single replacement 2) double replacement 1_ A. 2Al + 3H 2 SO 4 Al 2 (SO 4 ) 3 + 3H 2 2_B. Na 2 SO 4 + 2AgNO 3 Ag 2 SO 4 + 2NaNO 3 1_C. 3C + Fe 2 O 3 2Fe + 3CO 12/16/201510

Dr Seemal Jelani Chem-100 Combustion A reaction in which a compound (often carbon) reacts with oxygen C + O 2 CO 2 CH 4 + 2O 2 CO 2 + 2H 2 O C 3 H 8 + 5O 2 3CO 2 + 4H 2 O C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O 12/16/201511

Dr Seemal Jelani Chem-100 Learning Check R3 Balance the combustion equation ___C 5 H 12 + ___O 2 ___CO 2 + ___H 2 O 12/16/201512

Dr Seemal Jelani Chem-100 Solution R3 Balance the combustion equation 1 C 5 H O 2 5 CO H 2 O 12/16/201513

Dr Seemal Jelani Chem-100 Oxidation and Reduction  Reactions that involve a loss or gain of electrons  Occurs in many of the 4 types of reactions and combustion  Important in food metabolism, batteries, rusting of metals 12/16/201514

Dr Seemal Jelani Chem-100 Requirements for Oxidization- Reduction Electrons are transferred Two processes occur Oxidation = Loss of electrons (LEO) ZnZn e - Reduction = Gain of electrons (GER) Cu e - Cu 12/16/201515

Dr Seemal Jelani Chem-100 Balanced Red-Ox Equations Combine the oxidation and reduction reactions to make Loss of electrons = Gain of electrons Zn + Cu e - Zn e - + Cu Zn + Cu 2+ Zn 2+ + Cu 12/16/201516

Dr Seemal Jelani Chem-100 Gain/Loss of Hydrogen In organic and biological reactions oxidation = Loss of H reduction = Gain of H 12/16/201517

Dr Seemal Jelani Chem-100 Learning Check R3 Identify the following as an 1) oxidation or a reduction process: __A. SnSn e- __B. Fe e - Fe 2+ __C. Cl 2 + 2e - 2Cl - 12/16/201518

Dr Seemal Jelani Chem-100 Solution R3 Identify the following as an 1) oxidation or a reduction process: 1_ A. SnSn e- 2_ B. Fe e - Fe 2+ 2_ C. Cl 2 + 2e - 2Cl - 12/16/201519

Dr Seemal Jelani Chem-100 Learning Check R4 In light-sensitive sunglasses, UV light initiates an oxidation-reduction reaction Ag + + Cl - Ag + Cl A. Which reactant is oxidized 1) Ag + 2) Cl - 3) Ag B. Which reactant is reduced? 1) Ag + 2) Cl - 3) Cl 12/16/201520

Dr Seemal Jelani Chem-100 Solution R4 In light-sensitive sunglasses, UV light initiates an oxidation-reduction reaction Ag + + Cl - Ag + Cl A. Which reactant is oxidized 2) Cl - Cl - Cl + e - B. Which reactant is reduced? 1) Ag + Ag + + e- Ag 12/16/201521

Dr Seemal Jelani Chem /16/201522