1. HOW DO WE KNOW A CHEMICAL CHANGE/REACTION HAS OCCURRED?

2. let’s go to one of the old classics

3. BAKING SODA & VINEGAR (ACETIC ACID) REACTION
NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2
BAKING SODA
ACETIC ACID (VINEGAR)
SODIUM ACETATE
WATER
CARBON DIOXIDE 
REACTANTS
PRODUCTS

4. BAKING SODA & VINEGAR (ACETIC ACID) REACTION
What gas is produced?
BAKING SODA & VINEGAR (ACETIC ACID) REACTION
NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2
BAKING SODA
VINEGAR
SODIUM ACETATE
WATER
CARBON DIOXIDE 
REACTANTS
PRODUCTS

5. BAKING SODA & VINEGAR (ACETIC ACID) REACTION
What gas is produced? CO2
BAKING SODA & VINEGAR (ACETIC ACID) REACTION
NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2
BAKING SODA
VINEGAR
SODIUM ACETATE
WATER
CARBON DIOXIDE 
REACTANTS
PRODUCTS

6. does carbon dioxide fuel a fire?
Does FIRE need CO2?

7. does carbon dioxide fuel a fire?
Does FIRE need CO2?
As a REACTANT?
NO!!!

8. does carbon dioxide fuel a fire?
Does FIRE need CO2?
NO!!!
OXYGEN FUELS
A FIRE!

9. See how oxygen gas (O2) is a reactant in all of these…
4Fe + 3O2 à 2Fe2O3 C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 2CH2 + 3O2 à 2CO2 + 2H2O 2C4H O2 à 8CO2 + 10H2O
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

10. Which one is the rusting/corroding of iron?
4Fe + 3O2 à 2Fe2O3 C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 2CH2 + 3O2 à 2CO2 + 2H2O 2C4H O2 à 8CO2 + 10H2O
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

11. Which reaction seems to be the most sensitive/tempermental?
4Fe + 3O2 à 2Fe2O3 IRON RUSTING/CORRODING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 2CH2 + 3O2 à 2CO2 + 2H2O 2C4H O2 à 8CO2 + 10H2O
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

12. Which one needs the least oxygen to make the most products?
4Fe + 3O2 à 2Fe2O3 IRON RUSTING/CORRODING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 2CH2 + 3O2 à 2CO2 + 2H2O 2C4H O2 à 8CO2 + 10H2O
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

13. That second reaction is the combustion/explosion of c4!!!
4Fe + 3O2 à 2Fe2O3 IRON RUSTING/CORRODING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O 2C4H O2 à 8CO2 + 10H2O
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

14. The last 2 are the combustion reactions for wax and butane.
4Fe + 3O2 à 2Fe2O3 IRON RUSTING/CORRODING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O CANDLE WAX BURNING 2C4H O2 à 8CO2 + 10H2O BUTANE LIGHTER
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

15. COMBUSTION & CORROSION NEED
If were on a submarine undersea, and you had only candles and butane to keep you warm, which would you use?
4Fe + 3O2 à 2Fe2O3 IRON RUSTING/CORRODING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O CANDLE WAX BURNING 2C4H O2 à 8CO2 + 10H2O BUTANE LIGHTER
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

16. COMBUSTION & CORROSION NEED
If we’re on a submarine undersea, candles uses up less oxygen in its reaction.
4Fe + 3O2 à 2Fe2O3 IRON RUSTING/CORRODING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O CANDLE WAX BURNING 2C4H O2 à 8CO2 + 10H2O BUTANE LIGHTER
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

17. oxygen helps rust, combust, fire-up & explode!!!
4Fe + 3O2 à 2Fe2O3 IRON RUSTING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O CANDLE WAX BURNING 2C4H O2 à 8CO2 + 10H2O BUTANE LIGHTER
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

18. DUMB QUESTION: ARE OXIDATION REACTIONS EXO OR ENDOTHERMIC?

19. COMBUSTION & CORROSION NEED
oxygen helps rust, combust, fire-up & explode! OXIDATION REACTIONS ARE EXOTHERMIC
4Fe + 3O2 à 2Fe2O3 IRON RUSTING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O CANDLE WAX BURNING 2C4H O2 à 8CO2 + 10H2O BUTANE LIGHTER
COMBUSTION & CORROSION NEED
OXYGEN AS A REACTANT– THEREFORE,
WE CALL THESE OXIDATION REACTIONS

20. To stop oxidation/combustion reactions, we shut off the supply of ________ gas reactant.
Fire extinguishers either release water or carbon dioxide foam.
Blanket or covering a fire stops the oxygen from reaching the flame.

21. To stop oxidation/combustion reactions, we shut off the supply of oxygen gas reactant.
Fire extinguishers either release water or carbon dioxide foam.
Blanket or covering a fire stops the oxygen from reaching the flame.

22. COMBUSTION & CORROSION NEED reactant, the whole reaction STOPS!
oxygen helps rust, combust, fire-up & explode! OXIDATION REACTIONS ARE EXOTHERMIC
4Fe + 3O2 à 2Fe2O3 IRON RUSTING C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2 C4 EXPLOSION 2CH2 + 3O2 à 2CO2 + 2H2O CANDLE WAX BURNING 2C4H O2 à 8CO2 + 10H2O BUTANE LIGHTER
COMBUSTION & CORROSION NEED
OXYGEN without oxygen gas as a
reactant, the whole reaction STOPS!

23. Check for understanding…

24. Which gas can STOP combustion?
OXYGEN GAS (O2)
CARBON DIOXIDE (CO2)

25. Which gas can STOP combustion?
CARBON DIOXIDE (CO2)
OXYGEN GAS (O2)
OMG…this STARTS the whole thing!!!

26. What’s a heavier molecule: CO2 or O2?
Which has more atomic mass?

27. What’s a heavier molecule: CO2 or O2?
Use your periodic tables!!!

28. COMPARE MOLECULAR MASS!
CARBON DIOXIDE
OXYGEN GAS
16+16

29. Carbon dioxide CO2 is a heavier molecule!
OXYGEN GAS
= 44
16+16 = 32

30. Anyways…

31. Let’s compare Compare reactions:
Vinegar & baking soda reaction NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2 Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O

32. What if I replaced the O2 reactant in the candle burning reaction with CO2?
Vinegar & baking soda reaction NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2 Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O

33. What if I replaced the O2 reactant in the candle burning reaction with CO2?
Vinegar & baking soda reaction NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2 Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O
The reaction
would stop &
the flame would
go out!

34. Where can I get a whole lot of carbon dioxide to find out!
That old classic reaction that’s where!

35. BAKING SODA & VINEGAR (ACETIC ACID) REACTION
YES!!!
BAKING SODA & VINEGAR (ACETIC ACID) REACTION
NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2
BAKING SODA
VINEGAR
SODIUM ACETATE
WATER
CARBON DIOXIDE 
REACTANTS
PRODUCTS

36. And we Know now that CO2 is a heavier gas compared to O2!
That old classic reaction that’s where!

37. CO2 pours into the beaker & replaces the O2 reactant in the candle reaction.
Vinegar & baking soda reaction NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2 Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O
The reaction
stops & the
flame goes out!

38. CO2 pours into the beaker & replaces the O2 reactant in the candle reaction.
Vinegar & baking soda reaction NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2 Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O
The reaction
stops & the
flame goes out!

39. replace the O2 reactant WITH HEAVIER CO2 SHUTS DOWN THE REACTION!.
Vinegar & baking soda reaction NaHCO3 + HC2H3O2  NaC2H3O2 + H2O + CO2 Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O
The reaction
stops & the
flame goes out!

40. How did we know the baking soda reacted with the vinegar?

41. EVIDENCE of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
1. 2. a. b

42. EVIDENCE of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is produced (fizzes up)

43. How did we know the candle burning was a combustion chemical reaction?

44. EVIDENCE of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is produced
a TEMPERATURE change

45. Some chemical reactions RELEASE heat!
W_ _ m pack, butane l_ _ _ter, c_ _dle, f_ _ewor_ _,

46. Some chemical reactions RELEASE heat!
Warm pack, butane lighter, candle, fireworks,

47. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is produced
a TEMPERATURE change
temp heat EXITS reaction--EXOTHERMIC

48. Heat is released during EXOTHERMIC chemical reactions.
Candle wax burning reaction 2CH2 + 3O2 à 2CO2 + 2H2O + HEAT Hand warmers 4Fe + 3O2  2Fe2O3 + heat Potassium permagneate & glycerin 14 KMnO4 + 4 C3H5(OH)3  7K2CO3 + 7Mn2O3 + 5CO2 + 16H2O + HEAT

49. How about PHOTOSYNTHESIS
How about PHOTOSYNTHESIS? Do phytoplankton and trees release OR absorb heat?

50. With PHOTOSYNTHESIS, phytoplankton and trees ABSORB the SUN’s heat

51. That’s partly why its cooler to lay on your lawn than on your driveway during the summer!

52. trees absorb heat when doing photosynthesis
That’s why its cooler to walk through the shaded forest than a shaded garage.
trees absorb heat when doing photosynthesis

53. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is created as a product
a TEMPERATURE change
temp heat EXITS reaction—EXOTHERMIC
temp heat ENTERS reaction-ENDOthermic

54. Can you think of any ENDOthermic reactions that cool thing down in your home?

55. FRIDGES & AIR CONDITIONERS USE ENDOTHERMIC REACTIONS.

56. Check out this ENDOthermic reaction!
Barium hydroxide (Ba(OH)2) mixed with ammonium chloride (NH4Cl)…
HEAT + Ba(OH)2 + 8 H2O + 2 NH4Cl → 2 NH H2O + BaCl2

57. Some reactions ABSORB heat!
Barium hydroxide (Ba(OH)2) mixed with ammonium chloride (NH4Cl)…
HEAT + Ba(OH)2 + 8 H2O + 2 NH4Cl → 2 NH H2O + BaCl2
COLD PACK! REFRIDGERATORS! PHOTOSYNTHESIS!!!

58. what other signs do we have that a chemical reaction/change has occurred????

59. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is created as a product
a TEMPERATURE change
temp heat EXITS reaction—EXOTHERMIC
temp heat ENTERS reaction-ENDOthermic
A ??????????????change

60. A BIG _ _ _ _ _ change is an OBVIOUS sign of chemical reaction & change.
_ _ _ _ _ change indicates a new substances has been formed…
first 1:14 of
then 7:25-8:10

61. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is created as a product
a TEMPERATURE change
temp heat EXITS reaction—EXOTHERMIC
temp heat ENTERS reaction-ENDOthermic
a DRAMATIC COLOR change

62. Sulfuric acid helps oxidizing sugar shows all 4 signs of a chemical change…BUT ESPECIALLY COLOR CHANGE!
C12H22O O CO2 + 8 C + 11 H2O
H2SO4

63. Sulfuric acid helps oxidizing sugar shows all 4 signs of a chemical change…BUT ESPECIALLY COLOR CHANGE!
What role does sulfuric acid H2SO4 play in this chemical reaction?
C12H22O O CO2 + 8 C + 11 H2O
H2SO4

64. Sulfuric acid helps oxidizing sugar shows all 4 signs of a chemical change…BUT ESPECIALLY COLOR CHANGE!
What role does sulfuric acid H2SO4 play in this chemical reaction?
C12H22O O CO2 + 8 C + 11 H2O
CATALYST
H2SO4

65. Behold the GLOW STICK reaction!
C14H10O4 + H2O __C6H6O + C2O4

66. How many molecules of C6H6O do we make here?
C14H10O4 + H2O __C6H6O + C2O4

67. Behold the GLOW STICK reaction!
C14H10O4 + H2O C6H6O + C2O4

68. A BIG color change is an OBVIOUS sign of chemical reaction & change.
Color change indicates a new substances has been formed…
first 1:14 of
then 7:25-8:10

69. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is created as a product
a TEMPERATURE change
temp heat EXITS reaction—EXOTHERMIC
temp heat ENTERS reaction-ENDOthermic
a DRAMATIC COLOR change
WHAT’S THE LAST SIGN?????

70. corroded batteries and pennies…

71. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is created as a product
a TEMPERATURE change
temp heat EXITS reaction—EXOTHERMIC
temp heat ENTERS reaction-ENDOthermic
a DRAMATIC COLOR change
a PRECIPITATE forms

72. But what is a PRECIPITATE?

73. Batteries are chemical reactions inside a metal shell or plastic box
Batteries are chemical reactions inside a metal shell or plastic box. When these reactions occur, often we get a precipitate.

74. SIGNS of a CHEMICAL REACTION (aka a CHEMICAL CHANGE)
a GAS is created as a product
a TEMPERATURE change
temp heat EXITS reaction—EXOTHERMIC
temp heat ENTERS reaction-ENDOthermic
a DRAMATIC COLOR change
a PRECIPITATE forms
WHEN REACTANTS TURN INTO NEW SOLID PRODUCTS

75. nylon rope demo

76. END onto blue lab