1. ELECTROMAGNETIC ENERGY
REVIEW TIME!
What type of energy cooks food in a microwave oven?
ELECTROMAGNETIC ENERGY
What type of energy is the spinning plate inside of a microwave oven?
MECHANICAL ENERGY

2. Kinetic + Potential! (Mechanical energy)
What type of Energy?
Kinetic + Potential!
(Mechanical energy)

3. QUIZ TIME!
Electrical energy is transported to your house through power lines.
When you plug an electric fan to a power outlet, electrical energy is transform into what type of energy?
MECHANICAL ENERGY

4. QUIZ TIME!
What energy transformation occurs when an electric lamp is turned on?
ELECTRICAL ENERGY 
ELECTROMAGNETIC ENERGY
(Light energy)

5. Energy Transfer Sound (mechanical) Electrical Thermal Mechanical
Chemical
Electrical
Light
(Electromagnetic)

6. Do Now-YOU HAVE 10 minutes. Work Quickly!
Get with your group.
Complete your group worksheet.
Practice your presentation ATLEAST once.
Designate one person in your group to hold up the appropriate types of energy cards at the end of the presentation.
Make this OSCAR-worthy!!

7. And the Oscar goes to…
Take a piece of scrap paper and rip it into 3 parts
On one piece, nominate someone for BEST ACTOR
On another piece, nominate someone for BEST SUPPORTING ACTOR
On the last piece, nominate a BEST MOVIE (list the scenario you enjoyed seeing played out the best)

8. Thermochemistry
The study of heat change in chemical reactions.

9. Heat Change in Chemical Reactions
For a chemical reaction to occur, bonds must be both formed and broken
Fe + CuSO Cu FeSO4
Energy is needed to break bonds.
Energy is released when bonds are formed.

10. Exothermic process is any process that gives off heat – transfers thermal energy from the system to the surroundings.
2H2 (g) + O2 (g) H2O (l) + energy
H2O (g) H2O (l) + energy
Endothermic process is any process in which heat has to be supplied to the system from the surroundings.
energy + H2O (s) H2O (l)
energy + 2HgO (s) Hg (l) + O2 (g)
6.2

12. Thermochemical Equations
4Fe (s) O2 (g)  2Fe2O3 (s) kJ
Does this reaction give off heat or absorb heat?
Exothermic or endothermic?

13. Thermochemical Equations
C (s) S (s) kJ  CS2 (l)
Is heat released or absorbed in this chemical reaction?
Exothermic or endothermic?

14. DH = H (products) – H (reactants)
Enthalpy (H) is used to measure the heat flow into or out of a system in a process that occurs at constant pressure.
DH = H (products) – H (reactants)
Hproducts < Hreactants
Hproducts > Hreactants
DH < 0
DH > 0
6.3

15. Enthalpy(heat flow) is measured in:
Joules (J)
Kilojoules (kJ)
1 kJ = 1000 Joules

16. is positive, ∆H is positive
Energy Level Diagrams
Endothermic reactions
energy
products
energy taken in
is positive, ∆H is positive
reactants
The products are higher in energy than the reactants
time of reaction

17. is negative; ∆H is negative
Energy Level Diagrams
Exothermic reactions
Energy given out
is negative; ∆H is negative
energy
reactants
products
Time of reaction
The products are lower in energy than the reactants

18. Endothermic or Exothermic?

19. Endothermic or Exothermic?
What does DH equal?
80kJ-160kJ = -80kJ
DH = H (products) – H (reactants)

20. Endothermic or Exothermic?
What does DH equal?
DH = H (products) – H (reactants)

21. Endothermic or Exothermic?
What does DH equal?
DH = H (products) – H (reactants)

22. Endothermic or Exothermic?
What does DH equal?
DH = H (products) – H (reactants)

23. Endothermic or Exothermic?

24. Consider this reaction:
2C2H O2 → 4CO H2O kJ
a. endothermic or exothermic?
b. If 28 moles of oxygen are reacted, how much energy will be produced?
exothermic
3,120 x 4 = 12, 480 kJ