2. Purpose
The purpose of second part of this unit is to investigate and understand energy, energy transfers/storages, and energy involved in chemical reactions.
We are going to do this through modeling of a phenomena— The Hindenburg Disaster 1937

3. The Hindenburg Story

5. Complete your initial thoughts
Hindenburg Airship
Before
During
After
HoWhy did the Hindenburg burn in 37 seconds?
Complete your initial thoughts

6. Your Initial Group Models
Before
During
After
How did the Hindenburg burn in 37 seconds?

7. End of Day 1

8. Question: How did the Hindenburg
Big Idea Investigate and understand energy, energy transfers/storages, and energy involved. in chemical reactions.
Question: How did the Hindenburg
burn in 37 seconds?
Today:
Exploring Energy

9. What is Energy?
Energy is the stuff that makes stuff (particles) do stuff.
Energy is required to make things change
Energy is the ability to do work. (Phys. Science)
Work is the application of a force to move an object in the direction of the direction of the force.
A force is an influence that can cause an object to move or stop an object that is already moving.
Motion is a change in distance over time.

10. 1 Kind of Energy
1. Energy is energy— There is only one kind of energy called energy.
2. Things you can do to energy: store or transfer

11. Accounts- Where can “money” be.
Spend Now Have to do some work to spend

12. 1 Kind of Energy
3. Energy is stored in different accounts:

13. Ways Energy is Stored Kinetic Energy Potential Energy
Electrical Energy
Thermal Energy
Sound Energy
Radiant Energy
Movement Energy
Chemical Energy
Phase Energy
Mechanical Energy
Nuclear Energy
Gravitational Energy

14. Unit 3- Chemical Energy Notes

15. The 1st Law of Thermodynamics
Key Concept 1: The first law of thermodynamics states that energy can neither be created nor destroyed. Energy is conserved.
Law of Conservation of Energy

16. KC 2: Movement Energy (KE)
When objects or materials flow or move from one place to another they produce energy, such as water flowing through a dam.

17. KC 3: Electrical Energy (KE)
The energy associated with the movement of electrons.
Electrical charges moving through a wire is called electricity.
Lightning is another example

18. KC 4: Thermal Energy (KE)
The energy that results from the movement of atoms and molecules and is related to their temperature.
The faster particles move, the greater amount of energy and the higher the temperature.

19. KC 5: Sound Energy (KE)
Produced by the periodic movement of matter in a medium.
Sound can travel through air, solids, and liquids, but not through a vacuum, because there is no matter there.

20. KC 6 : Radiant Energy (KE)
Electromagnetic waves are a result of the vibration of charged particles such as electrons.
Microwave ovens use radiant energy to heat food by causing the water molecules to vibrate.

21. KC 7 : Mechanical Energy (PE)
Energy is stored in the mechanical device by the application of a force, such as when we wind the clock or pull the bow back.
Examples include a clock that is powered by a wound-up spring, or a bow and arrow.

22. KC 8: Nuclear Energy (PE)
When the nucleus of an atom splits or is fused to another nucleus, energy can be released.
It is the type of energy that powers our sun and is found in nuclear power plants.

23. KC 9: Gravitational Energy (PE)
This is the energy associated with an object’s position in a gravitational field.
A ball resting at the top of a ramp has higher potential energy than when it has rolled to the bottom.
Water behind a dam has higher potential energy than when it has flowed to the river below.
In each case the potential energy is due to relative position in the gravitational field.

24. KC 10: Chemical Energy (PE)
Is energy stored in a substance chemical bonds.
It takes energy to break bonds and energy is released when new bonds form.
Chemical bonds hold atoms together.

25. KC 11: Phase Energy (PE)
Is energy stored in a substance based on the arrangement of particles.

26. Learning Check
What type of energy is shown here?

27. Learning Check
What type of energy is shown here?

28. Learning Check
What type of energy is shown here?

29. Energy Flow Diagrams
Key Concept 12: Energy Flow Diagrams illustrate how energy is stored or transferred in a system or object.
There is often branching where one form of energy can be transformed into two or more other forms at the same time.
Example: Cell Phone
thermal

30. Learning Check Don’t Try This At Home Key Concept 13:
What type of energy is shown here?
Energy Flow Diagram

31. Exploring Energy Lab
Goal: Determine the kinds of energy involved with the operation of common toys and draw energy flow diagram to illustrate how energy is transferred.

32. Exploring Energy Lab Part 1: Gathering Evidence (1 pts each)
Write a description of what you observe.
Part 2: Analyzing Evidence (1 pts each)
Use the list of “types” of energy involved in the operation of each toy (Key Concepts 2 -11).
Part 3: Interpreting Evidence (3 pts each)
Draw an energy flow diagram to represent the energy storages/transfers (Key Concept 12 &13).
Part 4: Conclusion
Answer 2 of the 6 conclusion questions (Your choice!)
Turn in to the bin.

33. End of Day 2

34. How do these hand warmers work?
Pick up here with 5th hour

35. Now we get to mess with Chemical Energy
Pick up here with 5th hour

36. What are our energy accounts?
Eth Account- Thermal Energy (KC 4)- is the energy stored by moving particles.
Deposit- Move faster
Withdraw- Move slower
Eph Account- Phase Energy (KC 11)- is the energy stored in the system due to the arrangement of particles that exert attractions on one another.
Deposit- Break up the arrangement (decrease intermolecular forces)
Withdrawal- Allow arrangement to reform (increase intermolecular forces)
Pick up here with 5th hour

37. What are our energy accounts?
Key Concept 14: Ech- Chemical Energy (KC 10 )- is the energy due to attractions of atoms within molecules.
Deposit- During a chemical reaction, the energy stored in the reactants bonds is less than the products bonds.
Withdrawal- During a chemical reaction, the energy stored in the reactants bonds is greater than the products bonds.
Pick up here with 5th hour

38. LOL’s with Chemical NRG
In our quick hand warmer demo, the oxygen in the air reacted with the iron powder to create rust and heat. Draw an energy bar chart to represent the energy storage and transfer.

39. LOL’s with Chemical NRG
Key Concept 15: Hand warmer demo

40. LOL’s with Chemical NRG
Key Concept 16: In LOLOL diagrams, the amount of energy between reactants and products in a chemical reaction must be equal within the system (1st law of Thermodynamics cannot be broken).

41. Chemical Energy Demos - Energy Flow Diagrams -LOL

42. End of Day 3

43. Bellwork
Looking at Demo 2 and 3 from yesterday and your prior knowledge about the vocabulary exothermic vs. endothermic from biology; copy and complete the following 2 sentences.
In an endothermic reaction energy is released to/ absorbed from the surroundings and demo # 2/3 was an example of an endothermic reaction.
In an exothermic reaction energy is released to/ absorbed from to the surroundings and demo # 2/3 was an example of an exothermic reaction.

44. Endothermic Reactions
Key Concept 17: Endothermic reactions are chemical reactions where the system absorbs energy from its surroundings in the form of heat.
Ech
for
Reactants
Ech
for
Products

45. Exothermic Reactions
Key Concept 18: Exothermic reactions are chemical reactions that release energy to the surroundings in the form of light or heat.
Ech
for
Reactants
Ech
for
Products

46. End of Day 4

47. Bellwork
How do you think instant hot and cold packs work? (5 Sentences) Keep in mind chemical reactions and energy.

48. Hot or Cold Pack??? Experiment A (odd numbered lab stations):
You will be mixing spoon full of sodium bicarbonate (NaHCO3) that is in beaker A, with 2 squirts of water in a sandwich bag.
Experiment B (even numbered lab stations):
You will be mixing spoon full of calcium chloride (CaCl2) that is in beaker B, with 2 squirts of water in a sandwich bag.

50. Quick Lab Conclusion Questions
Key Concept 19 : Complete the following sentence starters for both experiments
Experiment ___ (A/B) is similar to ___ (hot/cold pack).
The heat energy is _____ (given off/taken in).
The temperature _____ (falls/rises).
Reaction ___ (A/B) is _____ (endothermic/exothermic)
Repeat for other experiment

51. Activation Energy
Key Concept 20: Activation energy is the minimum amount of energy required to initiate a chemical reaction.
Is any reaction spontaneous?
Needs activation energy

52. Chemical Energy
Chemists are interested in changes in energy during reactions.
Key Concept 21: Enthalpy is a measure of the total energy in chemical bonds.
Enthalpy is also known as the heat of reaction, or H.
The change in enthalpy during a reaction symbolized as ΔHrxn.
ΔHrxn = Hfinal – Hinitial
ΔHrxn = Hproducts – Hreactants

53. KC 22: (Draw the graph) ∆ H is known as the “heat of the reaction”
Exothermic Reaction: A chemical reaction that releases energy in the form of light or heat.
Activation Energy
Energy of reactants
∆ H is known as the “heat of the reaction”
Energy of products
Energy
Reactants
-∆H Exothermic
Products
Reaction Progress

54. KC 23: (Draw the graph)
Endothermic Reactions: Chemical reactions that absorb energy in the form of heat
Energy of reactants
Activation
Energy
Energy of products
Products
Energy
+∆H Endothermic
Reactants
Reaction progress

55. End of Day 5

56. (Hint: Look at your notes KC 22 and 23)
Bellwork
Draw this energy diagram and label the reactants, products, heat of the reaction (enthalpy), activation energy, and whether the reactions is endothermic or exothermic.
(Hint: Look at your notes KC 22 and 23)

57. (T) Endo or (F) Exo… Which is it?
Rm Learning Check
(T) Endo or (F) Exo… Which is it?

58. Learning Check
(T) Endo or (F) Exo… Which is it?

59. What is the heat of reaction? What is the activation energy?
C is heat of the reaction and a is activation energy
Total energyused
What is the heat of reaction?
What is the activation energy?
Is the reaction endothermic or exothermic?

60. What is the heat of reaction? What is the activation energy?
C is heat of the reaction and a is activation energy
What is the heat of reaction?
What is the activation energy?
Is the reaction endothermic or exothermic?

61. 1) The heat of reaction for this reaction is:
A) +160 kJ B) +280 kJ
C) -160 kJ D) -280 kJ
2) The activation energy for this reaction is:
A) 20 kJ B) 60 kJ
C) 160 kJ D) 260 kJ
3) The following describes this reaction:
A) endothermic, +ΔH B) endothermic, -ΔH
C) exothermic, +ΔH D) exothermic, -ΔH

62. Move into desk partners and complete problems C 10-15
On your whiteboard write the concept that was the hardest or you still don’t understand, then bring your board up front.

63. Closure (Stamp) (Sketch in explain everything with your shoulder partner)
Sketch a potential energy curve that is represented by the following values of ΔH and activation energy. You may make up appropriate values for the y-axis (potential energy).
ΔH = -50 kJ and Activation Energy = 20 kJ
Is this an endothermic or exothermic reaction?

64. End of Day 6

65. Hoffman’s Apparatus

66. Summary
summary of differences
Endothermic
Exothermic

67. What’s the balanced reaction?
Oxygen gas (in the air) reacted with hydrogen gas (in the blimp) to form water.
Oxygen- Red Paper Clip
Hydrogen- Sliver Paper Clips
On the whiteboard- balance chemical equation and a particle diagram of the reaction.
Do not forget the Law of Conservation of Mass

68. KC 24: What’s the balanced reaction?

69. End of Day 6

72. Hindenburg Cigarette? Sabotage? Thunderstorm or Spark?
Outside Material covered in “Rocket-Fuel”?

73. Your Final Group Models
Before
During
After
How did the Hindenburg burn in 37 seconds?