1. Redox Reactions Synthesis Decomposition Single Replacement Combustion

2. objective I can classify redox reactions so I can recognize patterns of chemical behavior and predict the products of reactions.

3. Redox Reaction Review In an oxidation – reduction reaction (or Redox reaction), electrons are lost by one element and gained by another element. Reactions that involve elements as reactants or products are always redox. EX. Mg (s) + O 2 (g)  MgO (s)

4. Which of the following is a redox reaction? A.2K(s) + Cl 2 (g) → 2KCl(s) B.H 2 O 2 (aq) → H 2 O(l) + O 2 (g ) C.2Al(s) + 3Cu(SO 4 )(aq) → 3Cu(s) + Al 2 (SO 4 ) 3 (aq) D.CH 4 (g) + O 2 (g) → CO 2 (g) + 2H 2 O(l) E.all of the above are redox reactions

5. Which of the following is a redox reaction? A.2K(s) + Cl 2 (g) → 2KCl(s) B.H 2 O 2 (aq) → H 2 O(l) + O 2 (g ) C.2Al(s) + 3Cu(SO 4 )(aq) → 3Cu(s) + Al 2 (SO 4 ) 3 (aq) D.CH 4 (g) + O 2 (g) → CO 2 (g) + 2H 2 O(l) E.all of the above are redox reactions All have single elements in the reactants or products so ALL are redox reactions!!!

6. Redox Reactions We classify chemical reactions so that we can recognize patterns of chemical behavior, and predict the products that will form. The following four types of reactions are all considered Redox Reactions. 1.SynthesisA + B  AB 2.DecompositionAB  A + B 3.Single ReplacementA + BC  B + AC 4.CombustionC x H y + O 2  CO 2 + H 2 O

7. Synthesis Redox Reaction A + B  AB two or more substances combine to form a single substance. The two reactants are frequently a Metal and a non-Metal. The product that they form is then a(n) ionic compound. To write the correct formulas for ionic compounds, we use the criss-cross method.

8. Synthesis Redox Reaction A. Group A metals and a nonmetal react with each other to produce a compound made up of a metal cation and a nonmetal anion. __K + __Cl 2  ________ __K + __Cl 2  __KCl 2K + Cl 2  2KCl

9. Synthesis Redox Reaction A. Group A metals and a nonmetal react with each other to produce a compound made up of a metal cation and a nonmetal anion. __K + __Cl 2  ________ __ K + __ Cl 2  __ KCl

10. Synthesis Redox Reaction A. Group A metals and a nonmetal react with each other to produce a compound made up of a metal cation and a nonmetal anion. __K + __Cl 2  ________ __ K + __ Cl 2  __ KCl 2K + Cl 2  2KCl

11. Synthesis Redox Reaction B. More than one product is also possible when a transition metal and a nonmetal react. Fe + S  FeS i ron(II) sulfide (Fe 2+ ) 2Fe + 3S  Fe 2 S 3 iron(III) sulfide (Fe 3+ )

12. Synthesis Redox Reaction C. When two nonmetals react by synthesis, more than one product is often possible. S + O 2  SO 2 sulfur dioxide 2S + 3O 2  2SO 3 sulfur trioxide

13. Which of these is a synthesis redox reaction? A.CH 4 (g) + O 2 (g) → CO 2 (g) + 2 H 2 O(l) B.2H 2 O 2 (aq) → 2H 2 O(l) + O 2 (g) C.2K(s) + Cl 2 (g) → 2KCl(s)

14. Decomposition Redox Reaction AB  A + B In a decomposition reaction, a single compound is broken down into two or more products. –The reactant: a single compound –The products: more than one element or compound. Most decomposition reactions require a catalyst in the form of a chemical, heat, light, or electricity.

15. TNT C 7 H 5 N 3 O 6 TNT is one of the most commonly used explosives for military and industrial applications. 2 C 7 H 5 N 3 O 6(s) → 3 N 2(g) + 5 H 2(g) + 12 CO (g) + 2 C (s)

16. Which of these is a decomposition reaction? A.CH 4 (g) + O 2 (g) → CO 2 (g) + 2 H 2 O(l) B.2H 2 O 2 (aq) → 2H 2 O(l) + O 2 (g) C.2K(s) + Cl 2 (g) → 2KCl(s)

17. Lab Demonstrations Synthesis Reaction: “Iron reacts with oxygen to produce iron (III) oxide (rust)” Iron + oxygen  iron(III) oxide ____Fe(s) + ____O 2 (g)  ____Fe 2 O 3 (s) Decomposition Reactions: “In the presence of electricity, water decomposes to form oxygen and hydrogen” ____H 2 O(l)  ___H 2 (g) + ___ O 2 (g)

18. Warmup Jan 22 1.What is HOFBrINCl? 2.What symbol is used to indicate a solid substance in a chemical equation? 3.Balance each chemical equation and identify whether it is redox or precipitation: a. __Pb(s) + __AgNO 3 (aq)  __Ag(s) + __Pb(NO 3 ) 2 (aq) b. __CaCO 3 (aq) + __NaCl(aq)  __Na 2 CO 3 (aq) + __CaCl 2 (s) 4.What type of redox reaction are the following? a.8 FeS(s)  8 Fe(s) + S 8 (g) b.CO 2 (g) + NaO(s)  NaCO 3 (s)

19. REDOX REACTIONS PART II Single Replacement Combustion

20. Single-Replacement Reactions A + BC  B + AC A metal element replaces a second metal element in the compound. –“A replaces B” AC and BC are ionic compounds Example: 3 Mg (s) + 2 AlCl 3 (aq)  2 Al (s) + 3 MgCl 2 (aq)

21. Which of the following is a single replacement redox reaction? A.2 K(s) + Cl 2 (g) → 2 KCl(s) B.H 2 O 2 (aq) → H 2 O(l) + O 2 (g ) C.2 Al(s) + 3 Cu(SO 4 )(aq) → 3 Cu(s) + Al 2 (SO 4 ) 3 (aq) D.CH 4 (g) + O 2 (g) → CO 2 (g) + 2 H 2 O(l) E.none of the above

22. Which of the following is a single replacement redox reaction? A.2 K(s) + Cl 2 (g) → 2 KCl(s) B.H 2 O 2 (aq) → H 2 O(l) + O 2 (g ) C.2 Al(s) + 3 Cu(SO 4 )(aq) → 3 Cu(s) + Al 2 (SO 4 ) 3 (aq) D.CH 4 (g) + O 2 (g) → CO 2 (g) + 2 H 2 O(l) E.none of the above

23. Single Replacement Reactions A + BC  B + AC Not all single replacement reactions can occur. Whether metal A will replace metal B from the compound BC can be determined by the relative reactivities of the two metals.

24. Single Replacement Reactions A + BC  B + AC A reactive metal will only replace a metal listed below it in the Activity Series. Mg(s) + Zn(NO 3 ) 2 (aq)  Mg(s) + Li(NO 3 )(aq) 

25. Single Replacement Reactions A + BC  B + AC A reactive metal will only replace a metal listed below it in the Activity Series. Mg(s) + Zn(NO 3 ) 2 (aq)  Mg(NO 3 ) 2 (aq) + Zn(s) Mg(s) + Li(NO 3 )(aq) 

26. Single Replacement Reactions A + BC  B + AC A reactive metal will only replace a metal listed below it in the Activity Series. Mg(s) + Zn(NO 3 ) 2 (aq)  Mg(NO 3 ) 2 (aq) + Zn(s) Mg(s) + Li(NO 3 )(aq)  no reaction

27. Which of these is higher on the activity series? A.calcium B.magnesium

28. Which of these is higher on the activity series? A.hydrogen B.magnesium

29. A reactive metal will only replace a metal listed below it in the Activity Series. Which of these reactions will NOT occur? A.Mg(s) + 2HCl(aq)  H 2 (g) + MgCl 2 (aq) B.H 2 (g) + MgCl 2 (aq)  Mg(s) + 2HCl(aq)

30. Can this single replacement reaction occur? “aluminum reacts with rust to produce iron and aluminum oxide” 2Al(s) + Fe 2 O 3 (s)  2Fe(s) + Al 2 O 3 (s) A.Yes B.No

32. C x H y + O 2  CO 2 + H 2 O + energy A.In a combustion reaction, a compound reacts with oxygen to produce energy as heat, light or electricity. B.Reactants: hydrocarbons (compounds of hydrogen and carbon) and oxygen Products:carbon dioxide and water

33. You observe the combustion of butane C 4 H 10……. Which of these reactants must also be present? A.water B.carbon dioxide gas C.oxygen gas D.hydrogen gas C 4 H 10

34. Combustion reaction Example: CH 4 (g) + 2O 2 (g)  CO 2 (g) + 2H 2 O

35. Hydrocarbon molecule examples - C x H y octane C 8 H 18 propane C 3 H 8 methane CH 4

36. Which of these is a combustion reaction? A.C 3 H 8 (g) + 5 O 2 (g) → 3 CO 2 (g) + 4 H 2 O(l) B.2H 2 O 2 (aq) → 2H 2 O(l) + O 2 (g) C.2K(s) + Cl 2 (g) → 2KCl(s)

37. Redox Lab Demos Single Replacement: aluminum reacts with iron(III)oxide to replace the iron and forms aluminum oxide __Al(s) + __Fe 2 O 3 (s)  __Fe(s) + __Al 2 O 3 (s) Combustion: Propane (C 3 H 8 ) reacts with oxygen to produce carbon dioxide gas, water and heat. __ C 3 H 8 + __O 2  __ CO 2 + __H 2 O + heat Ethyl alcohol reacts with oxygen to produce carbon dioxide gas and water