1. Sponge: Set up Cornell Notes on pg. 13 2
Sponge: Set up Cornell Notes on pg Chemical Reactions Essential Question: Hydrogen peroxide (H2O2) breaks down into water (H2O) and oxygen (O2). Explain why this is a chemical reaction. What are the reactants and products?
2.4 Chemical Reactions
Hydrogen peroxide (H2O2) breaks down into water (H2O) and oxygen (O2). Explain why this is a chemical reaction. What are the reactants and products?
Key Concept: Life depends on chemical reactions

2. When you hear the term chemical reaction, what comes to mind?
On the top of pg. 12
When you hear the term chemical reaction, what comes to mind?
Can you give examples of some chemical reactions?

3. ANSWER
Maybe you think of liquids bubbling in beakers. You probably do not think of the air in your breath, but most of the carbon dioxide and water vapor that you breathe out are made by chemical reactions in your cells

5. KEY CONCEPT Life depends on chemical reactions.

6. Bonds break and form during chemical reactions.
Chemical reactions change substances into different ones by breaking and forming chemical bonds
Ex: iron + oxygen= rust

7. Bill Nye- Chemical Reactions- 3 mins

8. Reactants and Products
Ex: Cellular Respiration
Reactants and Products
Reactants are the substances changed during a chemical reaction.
Oxygen and Glucose
Products are the substances made by a chemical reaction.
Carbon Dioxide
and
Water
Energy

9. 6CO2 + C6H12O6 -------- 6CO2 + 6H2O
Cellular Respiration
6CO2 + C6H12O  6CO2 + 6H2O
Reactants
Products

10. Pennies Experiment
Please write a hypothesis for each of the following:
Hypothesis
Pennies in Salt:
Pennies in Water:
Pennies in Vinegar:
Pennies in Vinegar and Salt:
Pennies in Water and Salt:

11. Was your hypothesis correct?
Pennies in Salt: Nothing
Pennies in Water: Nothing
Pennies in Vinegar: Nothing
Pennies in Vinegar and Salt: Pennies get cleaned!!!!
Pennies in Water and Salt: Nothing
Reactants:
copper, vinegar, and salt
Product:
Hydrochloric Acid

12. Pg. 12- Divide into 4 sections
Gummi Bear
Reactants:
Products:
Elephant’s Toothpaste
Reactants:
Products:
Sodium and Water
Reactants:
Products:
Sodium and Chlorine
Reactants:
Products:
Mentos and Diet Coke
Reactants:
Products:
Reactants vs. Products:

13. On pg. 12:
Name the reactants (2) and products (3) in the Gummi Bear chemical reaction.
Reactants:
Sucrose- Gummi Bear
Molten Potassium Chlorate
Products:
Carbon Dioxide
Water
Potassium Chloride

14. Name the reactants and products in the “Elephant’s Toothpaste” Video
Hydrogen Peroxide
Liquid Soap
Potassium Iodide
Products
O2 (oxidized) Foam
Heat
Name the reactants and products in the “Mentos and Diet Coke” Video
Reactants
Mentos
Diet Coke
Products
CO2 Bubbles

15. Name the reactants and products in the “Sodium and Water” and “Sodium and Chlorine”
Sodium (toxic)
Chlorine (toxic)
Products
Sodium Chloride(Safe!!!!) aka Table Salt
Reactants
Sodium (toxic)
Water
Products
Hydrogen gas and Heat!!!!

16. On the very bottom of pg. 12:
What is the difference between reactants and products (in your own words)?
Give an example of each.

17. Products are the substances or new things made by a chemical reaction.
Answer
Reactants are the substances we start with, it is what will be changed during a chemical reaction
Products are the substances or new things made by a chemical reaction.
Ex: Oxidized Soap Foam + heat
Ex: H2O2 + liquid soap + sodium iodide

18. Sponge: Set up Cornell Notes on pg. 15 2
Sponge: Set up Cornell Notes on pg Chemical Reactions Essential Question: Describe how bonds break and form during chemical reactions
2.4 Chemical Reactions
Describe how bonds break and reform during chemical reactions

19. 6CO2 + C6H12O6 -------- 6CO2 + 6H2O
Cellular Respiration
6CO2 + C6H12O  6CO2 + 6H2O
Reactants
Products
For carbon dioxide and water to be made:
Bonds must be broken in the reactants
Bonds must form in the products
What causes these bonds to form and break???

20. Bond energy is the amount of energy that breaks a bond between two atoms
Energy is added to break bonds.
Energy is released when bonds form.
Ex: Breaking up H2O molecules using electricity
Ex: Forming H2O molecules

21. ENERGY is required to break bonds!!!!
Magnet Demonstration
How is bond formation represented by the snapping sound of the magnets?
It represents the energy released when bonds form!
How is bond breakage represented by the separation of the magnets?
In order to pull the magnets apart, ENERGY is needed.
ENERGY is required to break bonds!!!!

22. CO2 + H2O H2CO3 Chemical equilibrium
A reaction is at equilibrium when reactants and products form at the same rate.
CO2 + H2O H2CO3
Carbon dioxide + Water Carbonic acid
When the CO2 level is high in the blood, carbonic acid is formed
When the CO2 level is low in the lungs, carbonic acid is broken down

23. All chemical reactions involve changes in energy
Energy is both absorbed and released during chemical reactions
Energy is added to reactants to break bonds
When new bonds form in the products, energy is released

24. *Like the energy you would need to push a rock up a hill
Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction.
Draw this mini picture
*Like the energy you would need to push a rock up a hill

25. Exothermic reactions release more energy than they absorb
Releases energy into its surroundings often as heat, light, or electricity
Products have lower bond energy than the reactants.
Reactants  products + energy

26. Endothermic reactions absorb more energy than they release
Absorbs energy from its surroundings in the form of heat
Lowers surrounding temperature
Products have a higher bond energy than the reactants

27. Endothermic and Exothermic: Phase Change 4 min

28. Endothermic Reactions
Pg. 14
On the top 1/3 of pg. 14:
Please make a double-bubble map comparing and contrasting exothermic reactions with endothermic reactions.
Exothermic Reactions
Endothermic Reactions
On the middle 2/3 of pg. 14:
Please take notes on the video giving examples of endothermic and exothermic reactions

29. Endothermic and Exothermic Reactions Clip 1min

30. Exothermic or Endothermic?
Exo=Energy out (often as heat/light) Endo= absorbs energy

31. With your group:
Please use the internet/book to look up two-three of each
Exothermic reactions
Reactants and products?
Endothermic reactions

32. Endothermic and Exothermic Reactions Video 10 min

33. Involve chemical reactions
Releases more energy than is absorbed
Absorb more energy than is released
Involve chemical reactions
Excess energy released as heat or light
Endothermic reactions
Energy is absorbed and released
Exothermic reactions
Products have more bond energy than the reactants
Products have lower bond energy than the reactants
Involve changes in energy