1. AGENDA – May 25: Bonding Review – Any Questions? Bonding Review – Any Questions? Notes – Chemical Reactions Notes – Chemical Reactions Class work – go over balancing chemical equations challenge Class work – go over balancing chemical equations challenge HW –complete balancing equations handouts - for extra help go to: http://funbasedlearning.com/chemistry HW –complete balancing equations handouts - for extra help go to: http://funbasedlearning.com/chemistry http://funbasedlearning.com/chemistry

2. AGENDA – May 26: Bonding Quiz Bonding Quiz HW –go to: http://funbasedlearning.com/chemistry HW –go to: http://funbasedlearning.com/chemistry http://funbasedlearning.com/chemistry Complete “Classic Chembalancer” Complete “Classic Chembalancer”

3. Chapter 21.6 Chemical Reactions

4. Goals of this chapter: How to balance those equations (remember Law of Conservation of Mass) How to balance those equations (remember Law of Conservation of Mass) How to categorize chemical reactions: decomposition, combustion, single replacement, double replacement, combination How to categorize chemical reactions: decomposition, combustion, single replacement, double replacement, combination

5. CHEMICAL REACTION the changing of substances into other substances by the breaking of old bonds and the formation of new bonds the changing of substances into other substances by the breaking of old bonds and the formation of new bonds Consider the animation of the following reaction: Consider the animation of the following reaction:reaction CH 3 CH 2 OH + H 2 SO 4  H 2 O + C 2 H 4 + H 2 SO 4

6. In a chemical reaction: the way in which atoms are joined together changes the way in which atoms are joined together changes as reactants are converted to products, the bonds that hold atoms together are broken and new bonds are formed as reactants are converted to products, the bonds that hold atoms together are broken and new bonds are formed the atoms themselves are neither created nor destroyed the atoms themselves are neither created nor destroyed

7. REACTANTS  PRODUCTS The atoms in the products are the same atoms that were in the reactants, they are just arranged differently.

8. Symbols you will see and use when writing chemical equations:  Δ heat added-written above arrow  reversible reaction  Any symbol written above the arrow in a reaction indicates its use as a catalyst

9. Catalyst a substance that speeds up a reaction without being used up in the reaction

10. The Law of Conservation of Mass The Law of Conservation of Mass number and type  number and type

11. Balancing Chemical Equations Save O and H for last Save O and H for last If polyatomic does not break apart across the , count it as one element If polyatomic does not break apart across the , count it as one element Use trial and error: test various coefficients Use trial and error: test various coefficients

12. To write a chemical equation correctly, the number of atoms on the left side of a chemical equation (arrow) has to be precisely balanced with the atoms on the right side of the equation. To write a chemical equation correctly, the number of atoms on the left side of a chemical equation (arrow) has to be precisely balanced with the atoms on the right side of the equation. Balancing Chemical Equations

13. writing chemical equations, the number in front of the molecule's symbol ( coefficient ) indicates the number of molecules participating in the reaction-if no coefficient appears in front of a molecule, we interpret this as meaning one. writing chemical equations, the number in front of the molecule's symbol ( coefficient ) indicates the number of molecules participating in the reaction-if no coefficient appears in front of a molecule, we interpret this as meaning one. Balancing Chemical Equations

14. Try these:  S 8 + O 2  SO 3  HgO  Hg + O 2  Zn + HCl  ZnCl 2 + H 2  Na + H 2 O  NaOH + H 2  Fe 2 O 3 + H 2  Fe + H 2 O

15. Answers:  1, 12, 8  2, 2, 1  1, 2, 1, 1  2, 2, 2, 1  1, 3, 2, 3

16. and these…  H 3 PO 4 + HCl  PCl 5 + H 2 0  HCl + K 2 CO 3  KCl + H 2 O + CO 2  Ca(ClO 3 ) 2  CaCl 2 + O 2  C 2 H 5 OH + O 2  CO + H 2 O  Xe + F 2  XeF 6

17. Answers:  1, 5, 1,4  2, 1, 2, 1, 1  1, 1, 3  1, 2, 2, 3  1, 3, 1

18. AGENDA -May: Submit HW Submit HW Balancing Chemical Reactions Activity Balancing Chemical Reactions Activity HW – Describing Chemical Reactions WS HW – Describing Chemical Reactions WS

19. AGENDA -May: Submit HW Submit HW Notes – Chemical Reactions: Synthesis Notes – Chemical Reactions: Synthesis Class work – Synthesis WS 1 Class work – Synthesis WS 1 Homework – Synthesis WS 2 Homework – Synthesis WS 2

20. Pre-Class  NH 4 NO 3  N 2 O + H 2 O  Au 2 O 3  Au + O 2  C 4 H 10 + O 2  CO 2 + H 2 O  Fe 3 O 4 + H 2  Fe + H 2 O  I 2 + HNO 3  HIO 3 + NO + H 2

21. Answers:  1, 1, 2  2, 4, 3  2, 13, 8, 10  1, 4, 3, 4  2, 6, 4, 6, 1

22. 5 Types of Chemical Reactions  Combination (synthesis)  Decomposition  Single replacement  Double replacement  Combustion

23. Combination (synthesis) Reactants: either 2 elements OR 2 compounds Reactants: either 2 elements OR 2 compounds Product: MUST be a compound Product: MUST be a compound USUALLY combination is 2 reactants  1 product

24. Combination (synthesis) Examples Examples N 2 + 3H 2  2NH 3 2H 2 + O 2  2H 2 O 4P + 5O 2  2P 2 O 5 S 8 + 12O 2  8SO 3

25. Getting specific about synthesis : Two or more reactants  one product Two or more reactants  one productExamples: Na + Cl 2  2Na + Cl 2  2NaCl

26. Synthesis : Predicting Products Rb + Cl 2  Rb + Cl 2  RbCl 2Rb + Cl 2  2RbCl K + Cl 2  K + Cl 2  KCl not balanced 2K + Cl 2  2KCl

27. Synthesis : Predicting Products Ba + O 2  Ba + O 2  BaO not balanced 2Ba + O 2  2BaO Ca + Br 2  Ca + Br 2  CaBr 2 balanced as is

28. AGENDA -May: Submit HW & Pre-Class Submit HW & Pre-Class Notes – Chemical Reactions: Decomposition Notes – Chemical Reactions: Decomposition Class work – Decomposition WS #1 Class work – Decomposition WS #1 Homework – Decomposition WS #2 Homework – Decomposition WS #2

29. Decomposition The opposite of synthesis 2 KClO 3  2KCl + 3O 2 2Ag 2 O  4Ag + O 2

30. Decomposition Seltzer water (carbonic acid) decomposes to produce carbon dioxide and water: H 2 CO 3  CO 2 + H 2 O Decomposition: one reactant, two (or more products)

31. Getting specific about decomposition : one reactant  two or more products one reactant  two or more products Exact opposite of a synthesis reaction Exact opposite of a synthesis reaction Energy must be present (heat, light or electricity) Energy must be present (heat, light or electricity)

32. Examples of decomposition that you will have to be able to do: LiBr  LiBr  Li + Br 2 not balanced 2LiBr  2Li + Br 2 MgO  MgO  Mg + O 2 not balanced 2MgO  2Mg + O 2

33. AGENDA -MAY: Submit HW Submit HW Notes – Chemical Reactions: Single Replacement Notes – Chemical Reactions: Single Replacement Class work – Mini-Lab: Balancing Chemical Reactions Class work – Mini-Lab: Balancing Chemical Reactions Homework – Finish Mini-Lab Homework – Finish Mini-Lab

34. Single replacement one atom takes the place of another atom in a compound one atom takes the place of another atom in a compound A + BC  B + AC A has replaced B in this reaction A has replaced B in this reaction

35. Single replacement Examples Examples 2NaCl + F 2  2NaF + Cl 2 2NaCl + F 2  2NaF + Cl 2 Na + H 2 O  NaOH + H 2 Na + H 2 O  NaOH + H 2 K + MgBr 2  KBr + Mg K + MgBr 2  KBr + Mg

36. Single replacement Are either  Two metals and one nonmetal OR  Two nonmetals=halogens and one metal

37. Single replacement Examples of two metals and one nonmetal 2Al + 3CuCl 2  2AlCl 3 + 3Cu

38. Single replacement Examples of two nonmetals and one metal Mg + HCl  MgCl 2 + H 2

39. Try these SR reactions: Use the following steps: Identify which reactants are switching places Identify which reactants are switching places Determine neutral ratio for new compound Determine neutral ratio for new compound Draw reaction arrow and complete reaction Draw reaction arrow and complete reaction 1. MgBr 2 and Cl 2 2. Al and Fe 2 O 3 3. CuS and Mg 4. KI and F 2

40. Answers: 1. Magnesium Bromide and Chlorine MgBr 2 + Cl 2 MgBr 2 + Cl 2 Bromine and Chlorine Bromine and Chlorine ==> MgCl 2 + Br 2 ==> MgCl 2 + Br 2 2. Aluminum and Iron (III) Oxide Al + Fe 2 O 3 Al + Fe 2 O 3 Aluminum and Iron Aluminum and Iron ==> Fe + Al 2 O 3 ==> Fe + Al 2 O 3 2Al + Fe 2 O 3 ==> 2Fe + Al 2 O 3 2Al + Fe 2 O 3 ==> 2Fe + Al 2 O 3

41. Answers:  Copper (II) Sulfide and Magnesium CuS + Mg CuS + Mg Copper and Magnesium Copper and Magnesium ==> Cu + MgS ==> Cu + MgS  Potassium Iodide and Fluorine 2KI + F 2 2KI + F 2 Iodine and Fluorine Iodine and Fluorine ==> 2KF + I 2 ==> 2KF + I 2

42. AGENDA 13-MAY: Submit HW Submit HW Notes – Chemical Reactions: Double Replacement Notes – Chemical Reactions: Double Replacement Class work – Mini Lab: Balancing DR reactions Class work – Mini Lab: Balancing DR reactions Homework – Finish DR mini lab & Test Friday! Homework – Finish DR mini lab & Test Friday!

43. DOUBLE REPLACEMENT positive ions are always written first when listing the product positive ions are always written first when listing the product METALS are positive ions and NON- METALS are negative ions METALS are positive ions and NON- METALS are negative ions a positive must join with a negative a positive must join with a negative

44. Getting specific about double replacement : Involves the exchange of positive cations Involves the exchange of positive cations Gas, precipitate or water is always produced Gas, precipitate or water is always produced

45. Examples of double replacement: KBr + AgNO 3  KBr + AgNO 3  AgBr(s) + KNO 3 balanced Ppt formed HNO 3 + LiOH  HNO 3 + LiOH  LiNO 3 + H 2 O balanced Water formed

46. Try these STRATEGY: Determine charge on all atoms present and who is switching Determine charge on all atoms present and who is switching Create neutral compounds Create neutral compounds Balance equation! Balance equation! 1. BaCl 2 (aq) + K 2 S (aq)  2. FeS (s) + HCl (aq)  3. CaBr 2 (aq) + HCl 

47. Answers  BaCl 2 (aq) + K 2 S(aq) Ba 2+ Cl 1- + K 1+ S 2- Ba 2+ Cl 1- + K 1+ S 2- BaS + KCl BaS + KCl BaCl 2 (aq) + K 2 S(aq)  BaS(s) + 2KCl BaCl 2 (aq) + K 2 S(aq)  BaS(s) + 2KCl  FeS(s) + HCl(aq) Fe 2+ S 2- + H 1+ Cl 1- Fe 2+ S 2- + H 1+ Cl 1- H 2 S + FeCl 2 H 2 S + FeCl 2 FeS(s) + 2HCl(aq)  H 2 S(g) + FeCl 2 (aq) FeS(s) + 2HCl(aq)  H 2 S(g) + FeCl 2 (aq)  Ca(OH) 2 (aq) + 2HCl(aq) Ca 2+ OH 1- + H 1+ Cl 1- Ca 2+ OH 1- + H 1+ Cl 1- CaCl 2 + H 2 O CaCl 2 + H 2 O Ca(OH) 2 (aq) + 2HCl(aq)  CaCl 2 (aq) + 2H 2 O Ca(OH) 2 (aq) + 2HCl(aq)  CaCl 2 (aq) + 2H 2 O

48. Getting specific about double replacement : How to predict products:  ID cations  Switch them!  Write proper formulas  Balance

49. Examples of double replacement: FeCl 2 + K 2 S  FeCl 2 + K 2 S  FeS + KCl not balanced FeCl 2 + K 2 S  FeS + 2KCl Pb(NO 3 ) 2 + K 2 CrO 4  Pb(NO 3 ) 2 + K 2 CrO 4  PbCrO 4 + KNO 3 Pb(NO 3 ) 2 + K 2 CrO 4  PbCrO 4 + 2KNO 3

50. AGENDA -MAY: Notes – Chemical Reactions Notes – Chemical Reactions Identifying combustion reactions Identifying combustion reactions Class work – Reactions Packet Class work – Reactions Packet Homework – Finish Packet & Test Friday! Homework – Finish Packet & Test Friday!

51. Combustion Reactants: Carbon and Hydrogen containing compound reacting with oxygen Reactants: Carbon and Hydrogen containing compound reacting with oxygen Product: Carbon dioxide and water Product: Carbon dioxide and water C x H y + O 2  CO 2 + H 2 O

52. Getting specific about combustion : Oxygen is present on the reactant side. Hydrocarbon = C x H y Products are always carbon dioxide and water

53. Examples of combustion: C 2 H 2 + O 2  C 2 H 2 + O 2  CO 2 + H 2 O not balanced C 2 H 2 + 2.5O 2  2CO 2 + 1H 2 O 2C 2 H 2 + 5O 2  4CO 2 + 2H 2 O C 3 H 8 + O 2  C 3 H 8 + O 2  CO 2 + H 2 O not balanced C 3 H 8 + 5O 2  3CO 2 + 4H 2 O

54. AGENDA -MAY: No Notes! No Notes! Class work – Practice Test! Class work – Practice Test! Homework – Study! Homework – Study!

55. Predicting Product Formation - How to write products: Determine the type of reaction: synthesis, decomposition, s/d replacement, or combustion Determine the type of reaction: synthesis, decomposition, s/d replacement, or combustion Make sure elements present on left are present on right Make sure elements present on left are present on right Make sure all charges are net zero Make sure all charges are net zero Balance equation. Balance equation.

56. What we need to know for the Test: Balance Chemical Equations! Balance Chemical Equations!  Coefficients go in front of formulas, and multiply across them)  Subscripts DO NOT CHANGE! Identify Chemical Reactions Identify Chemical Reactions  Synthesis (one product)  Decomposition (one reactant)  Single Replacement (one element and one compound)  Double replacement (two ionic compounds, acids/bases)  Combustion (CO 2 and H 2 O Products)

57. An Overview Identifying Reactions  One product? Synthesis Reaction Synthesis Reaction  One reactant? Decomposition Decomposition  One compound and one element? Single replacement Single replacement  Two compounds? Double replacement Double replacement  One hydrocarbon (C x H y ) and oxygen? Combustion Combustion

58. An Overview SYNTHESIS Write chemical formulas for Ionic Compounds! Na + Cl 2 1. Determine charge on ions Na 1+; Cl 1- Na 1+; Cl 1- 2. Predict products and determine correct ionic formula Na 1+ + Cl 1-  NaCl Na 1+ + Cl 1-  NaCl 3. Balance Chemical Equation! 2 Na + Cl 2  2 NaCl 2 Na + Cl 2  2 NaCl

59. An Overview DECOMPOSITION MgBr 2 1. Break two elements up Mg; Br Mg; Br 2. Identify diatomic elements (if any) Bromine! Bromine! 3. Write out products MgBr 2  Mg + Br 2 MgBr 2  Mg + Br 2 4. Balance chemical reaction Balanced as is! Balanced as is!

60. An Overview SINGLE REPLACEMENT Write chemical formulas for Ionic Compounds! NaCl + K 1. Determine charge on ions Na 1+; Cl 1-; K 1+ Na 1+; Cl 1-; K 1+ 2. Predict products and switch ions Na 1+ Cl 1- + K 1+  K 1+ Cl 1- + Na 1+ Na 1+ Cl 1- + K 1+  K 1+ Cl 1- + Na 1+ 3. Determine correct ionic formula (criss-cross) NaCl + K  KCl + Na NaCl + K  KCl + Na 4. Balance Chemical Equation! Balanced as is! Balanced as is!

61. An Overview You Try! CaI 2 + Li 1. Determine charge on ions Ca 2+; I 1-; Li 1+ Ca 2+; I 1-; Li 1+ 2. Predict products and switch ions Ca 2+ I 1- + Li 1+  Li 1+ I 1- + Ca 2+ Ca 2+ I 1- + Li 1+  Li 1+ I 1- + Ca 2+ 3. Determine correct ionic formula (criss-cross) CaI 2 + Li  LiI + Ca CaI 2 + Li  LiI + Ca 4. Balance Chemical Equation! CaI 2 + 2 Li  2 LiI + Ca CaI 2 + 2 Li  2 LiI + Ca

62. An Overview DOUBLE REPLACEMENT Write chemical formulas for Ionic Compounds! Ca 3 N 2 + NaI 1. Determine charge on ions Ca 2+; N 3-; Na 1+; I 1- Ca 2+; N 3-; Na 1+; I 1- 2. Predict products and switch ions Ca 2+ N 3- + Na 1+ I 1-  Na 1+ N 3- + Ca 2+ I 1- Ca 2+ N 3- + Na 1+ I 1-  Na 1+ N 3- + Ca 2+ I 1- 3. Determine correct ionic formula (criss-cross) Ca 3 N 2 + NaI  CaI 2 + Na 3 N Ca 3 N 2 + NaI  CaI 2 + Na 3 N 4. Balance Chemical Equation! Ca 3 N 2 + 6 NaI  3 CaI 2 + 2 Na 3 N Ca 3 N 2 + 6 NaI  3 CaI 2 + 2 Na 3 N

63. An Overview You Try! Al 2 O 3 + Zn(NO 3 ) 2 1. Determine charge on ions Al 3+; O 2-; Zn 2+ NO 3 1- Al 3+; O 2-; Zn 2+ NO 3 1- 2. Predict products and switch ions Al 3+ O 2- + Zn 2+ NO 3 1-  Al 3+ NO 3 1- + Zn 2+ O 2- Al 3+ O 2- + Zn 2+ NO 3 1-  Al 3+ NO 3 1- + Zn 2+ O 2- 3. Determine correct ionic formula (criss-cross) Al 2 O 3 + Zn(NO 3 ) 2  Al(NO 3 ) 3 + ZnO Al 2 O 3 + Zn(NO 3 ) 2  Al(NO 3 ) 3 + ZnO 4. Balance Chemical Equation! Al 2 O 3 + 3 Zn(NO 3 ) 2  2 Al(NO 3 ) 3 + 3 ZnO Al 2 O 3 + 3 Zn(NO 3 ) 2  2 Al(NO 3 ) 3 + 3 ZnO

64. An Overview COMBUSTION Write chemical formulas for Ionic Compounds! C 3 H 8 + O 2 1. Recognize combustion reaction 2. Predict products C 3 H 8 + O 2  CO 2 + H 2 O C 3 H 8 + O 2  CO 2 + H 2 O 3. Balance Chemical Equation! C 3 H 8 + 5 O 2  3 CO 2 + 4 H 2 O C 3 H 8 + 5 O 2  3 CO 2 + 4 H 2 O

65. An Overview You Try! C 2 H 2 + O 2 1. Recognize combustion reaction 2. Predict products C 2 H 2 + O 2  CO 2 + H 2 O C 2 H 2 + O 2  CO 2 + H 2 O 3. Balance Chemical Equation! 2 C 2 H 2 + 5 O 2  4 CO 2 + 2 H 2 O 2 C 2 H 2 + 5 O 2  4 CO 2 + 2 H 2 O

66. AGENDA 3-JAN: Predicting Product formation QUEST THURSDAY Predicting Product formation QUEST THURSDAY 1. Questions? CW/REVIEW – Predicting Products Practice test CW/REVIEW – Predicting Products Practice test Homework – Part I of lab Homework – Part I of lab

67. AGENDA 4-JAN: Predicting Product formation QUEST TOMORROW Predicting Product formation QUEST TOMORROW 1. Questions? CW/REVIEW – LAB CW/REVIEW – LAB Homework – STUDY Homework – STUDY

68. AGENDA 5-JAN: QUEST

69. Pre-class (5 points) 1. Balance: Al + Cl 2  AlCl 3 2. What type of reaction is this? 3. What type of reaction is characterized by the breaking apart of a single reactant?

70. Pre-class (continued) 4. What is the formula for sodium sulfate? 5. Balance: CH 4 + O 2  H 2 O + CO 2

71. Pre-class (5 points) 1. What type of reaction is described by two elements of compounds switching places? 2. Identify the two contenders: CaCl 2 + 2Li  2LiCl + Ca 3. What type of reaction is #2?

72. Pre-class (continued) 4. What element is present in every combustion reaction? 5. Complete this single replacement reaction: CuCl 2 + K 

73. Pre-class (5 points) 1. Name the five types of chemical reactions we learned about. 2. What kind of reaction is this: BaCl 2 + Na 2 SO 4  BaSO 4 + NaCl BALANCE THIS REACTION

74. Pre-class (continued) 3. Write the product: Na + Cl 2  4. Balance the above reaction 5. Write the products of this HYDROCARBON combustion: C 2 H 4 + O 2 

75. Pre class (5 points) 1. What are the compounds written on the LEFT side of the arrow called? 2. TRUE or FALSE We can change subscripts in formulas to balance a chemical equation? 3. Balance this equation: Al + Fe 2 O 3  Fe + Al 2 O 3