1. Chemical Reactions & Chemical Equations

2. Chemical Reactions A process involving a substance or substances changing into a new substance or substances Chemical Change

3. Chemical Reactions Evidence of a chemical reaction

4. Chemical Reactions Evidence of a chemical reaction 1) A permanent color change 2) A gas is produced 3) Energy is exchanged 4) A precipitate is produced

5. Chemical Equations A statement using chemical formulas to describe the identities and relative amounts of reactants and products involved in the chemical reaction

6. Reactant(s)  Product(s)

7. MgCO 3  MgO + CO 2

8. MgCO 3  CO 2 + MgO

9. MgCO 3 (s)  MgO (s) + CO 2(g) Phases of Components (s) = solid (l) = liquid (g) = gas (aq) = aqueous

10. Physical Change Vs. Chemical Change

11. Physical ChangeChemical Change

12. Physical ChangeChemical Change Phase Changes Dissolving Mixing Breaking Separating Filtering Rearrange Atoms New Substances form

13. Did a chemical change occur? 1.Permanent Color Change Occurs 2.Precipitate Formed 3.Gas is Released 4.Energy is Exchanged – Temperature

14. Chemical Reaction Demonstration 1.Permanent Color Change CuSO 4 (Aq) + Zn (s)  ZnSO 4 (Aq) + Cu (s) Blue Gray Clear Black The Zn and Cu are Switching, this is known as a single replacement Reaction. 2.Gas is Produced HCl (l) + Zn (s)  ZnCl (Aq) + H 2 (g) 3.Energy is Exchanged Mg (s) + O 2 (g)  MgO (s) Rapid Oxidation 4.Precipitate is Formed Pb(NO 3 ) 2 (Aq) + K 2 CrO 4 (Aq)  KNO 3 (Aq) + PbCrO 4 (s) Clear Bright Yellow

15. Practice Exercise #1 1.Define Chemical Reaction 2.How do we know a chemical reaction has taken place? 3.What is a Chemical Equation and Why do we use them? 4.What are the initial constituents of a chemical reaction? What are the end products called? 5.What do the following symbols stand for? slgaq

16. Types of Chemical Equations

17. Synthesis Putting things together Also known as Direct Combination. 2 Na + Cl 2 = 2 NaCl 4 Al + 3 O 2 = 2 Al 2 O 3

18. Decomposition Breaking things down/Taking apart AKA Analysis 2 KClO 3 = 2 KCl + 3 O 2 3 MnO 2 = Mn 3 O 4 + O 2

19. Single Replacement Replacing one element in a compound with another element. 2 Al + 6 HCl = 2 AlCl 3 + 3 H 2 2 NaBr + Cl 2 = 2 NaCl + Br 2

20. Double Replacement Switching one element from a compound with another element from a different compound. 2 AgNO 3 + MgCl 2 = 2 AgCl + Mg(NO 3 ) 2 HCl + NaOH = NaCl + H 2 O

21. Others Combustion –Rapid Oxidation –XXXX + O 2 CO 2 + H 2 O Oxidation –Add Oxygen (Combustion) Reduction Acid – Base Neutralization Etc……

23. HW Due Monday Read & outline page 249-255

24. Exothermic Reactions Release or give off heat. Heat is a byproduct of the reaction. Temperature increases as the bonds between products are formed. Examples –Combustion, Respiration, Oxidation

25. Endothermic Reactions Take in or absorb Heat from the surroundings. Temperature decreases as the reaction progresses. Heat is used to break bonds of reactants. –Decomposition or Analysis Reactions

26. Oxidation Removing Electrons

27. Reduction Adding Electrons

28. Rate of Reaction Reactions occur at different speeds. The time it takes for reactants to become products.

29. Catalysts They speed up reactions without being affected themselves. –They stay the same –Enzymes in living organisms. Lowers activation energy –The amount of energy needed to start a reaction.

30. Speeding Up Reactions Temperature, Energy, Pressure, Surface Area, Concentration, Collisions, Catalyst.

31. Measuring Rates of Reactions Measure Reactants Measure Products

32. Balancing Chemical Equations

33. Reactant(s)Product(s)

34. MgCO 3 (s)  MgO (s) + CO 2(g) Phases of Components (s) = (l) = (g) = (aq) =

35. 1 MgCO 3 (s)  1 MgO (s) + 1 CO 2(g)

36. Reactants Products

37. 1 MgCO 3 (s)  1 MgO (s) + 1 CO 2(g) 5 atoms

38. H 2 + O 2  H 2 O

39. 2 H 2 + 1 O 2  2 H 2 O H 2 + H 2 + O 2  H 2 O + H 2 O

40. 2 H 2 + 1 O 2  2 H 2 O H 2 + H 2 + O 2  H 2 O + H 2 O

41. Ca + Cl 2  CaCl 2

42. Na + Cl 2  NaCl

43. Fe 2 O 3  Fe + O 2

44. AgNO 3 + NaCl  NaNO 3 + AgCl

45. FeS 2 + O 2  Fe 2 O 3 + SO 2

46. 4 FeS 2 + 11 O 2  2 Fe 2 O 3 + 8 SO 2

47. NH 4 OH + Ni(NO 3 ) 2  NH 4 NO 3 + Ni(OH) 2

48. NH 4 OH + Ni(NO 3 ) 2  NH 4 NO 3 + Ni(OH) 2

49. Na 2 CO 3 + Fe(NO 3 ) 3  Fe 2 (CO 3 ) 3 + NaNO 3

50. Na 2 CO 3 + Fe(NO 3 ) 3  Fe 2 (CO 3 ) 3 + NaNO 3 3 Na 2 CO 3 + 2 Fe(NO 3 ) 3  Fe 2 (CO 3 ) 3 + 6 NaNO 3 Balanced!!!

51. H 3 PO 4 + Ca(OH) 2  Ca 3 (PO 4 ) 2 + H 2 O

52. NH 4 OH + H 3 PO 4  (NH 4 ) 3 PO 4 + H 2 O

53. Al(OH) 3 + H 2 SO 4  Al 2 (SO 4 ) 3 + H 2 O

54. C 6 H 6 + O 2  CO 2 + H 2 O