Endothermic and Exothermic Reaction Notes

1. AGENDA: ENDOTHERMIC
EXOTHERMIC REACTIONS
NOTES
BELLWORK: HOW DO YOU KNOW A
CHEMICAL REACTION HAS OCCURRED?
SET UP CORNELL NOTES

2. HOW DO WE WRITE A CHEMICAL
REACTION?
Reactants (Starting compounds and elements)
P4 + 3O2 –> 2P2O3
Products (New compounds

3. WHY MUST A CHEMICAL REACTION BE
BALANCED?
Becauseeeeee……
Of the Law of Conservation of Matter…..
What does that mean?????
P4 + 3O2 –> 2P2O3
Seriously…. What does that mean?

4. WHY MUST A CHEMICAL REACTION BE
BALANCED?
Because……
Of the Law of Conservation of Matter…..
What does that mean?????
P4 + 3O2 –> 2P2O3
Seriously…. What does that mean?

5. WHY MUST A CHEMICAL REACTION BE
BALANCED?
The Law of Conservation of Matter
states that matter cannot be created or
destroyed. The # of atoms on the
reactant side must equal the # of
atoms on the product side.
P + 3O –> 2P O

6. LITTLE SYMBOLS?
P4 (s) + 3O2 (g) –> 2P2O3 (aq)
(s) (l) (g) (aq)
(s) - solid
(l) - liquid
(g) - gas
(aq) – dissolved in water (aqueous)

7. ENDOTHERMIC EXOTHERMIC REACTIONS
•https://www.youtube.com/watch?v=L
-G7pLufXAo

8. Endothermic reactions
IN Heat
• Heat energy is absorbed (comes
in) from the surroundings to the
system
Heat in  Feels
Reactio
n

9. Exothermic reactions
Out Heat
• Heat energy is released (goes out)
from the surroundings to the
system
Heat out  Feels
Reactio
n

10. ENDOTHERMIC AND EXOTHERMIC WRITTEN
IN EQUATIONS?
Heat + P4 + 3O2 –> 2P2O3
Endothermic because heat is added to start the
reaction.
P4 + 3O2 –> 2P2O3 + Heat
Exothermic because heat is released with the
product.

11. EXAMPLES OF ENDOTHERMIC REACTIONS?
THINK ABOUT HEAT ABSORBING TO CAUSE THE
CHANGE
Melting ice
Baking
cookies
Freezing ice
cream
Forming
clouds
(condensati
on)
Evaporation
Cooking
Forming a
gas from a
liquid
Burning
wood
Nuclear
fusion
Thaw
Chicken
Drying
Laundry
Freezing ice

12. EXAMPLES OF EXOTHERMIC REACTIONS?
THINK ABOUT HEAT BEING RELEASED AFTER THE
CHANGE
Melting ice
Baking
cookies
Freezing ice
cream
Forming
clouds
(condensati
on)
Evaporation
Cooking
Forming a
gas from a
liquid
Burning
wood
Nuclear
fusion
Thaw
Chicken
Drying
Laundry
Freezing ice

13. GRAPHING ENDO AND EXOTHERMIC REVIEW
WORKSHEET
•Glue or staple into notebook
•Complete worksheet
•Whole class review