1. The Law of Conservation of Matter

2. PLEASE COME IN… PICK UP 2 SHEETS OF NOTES AT THE FRONT OF THE ROOM
PLEASE TAPE/GLUE THEM ONTO PAGES 50-51
THIS SHOULD BE RIGHT AFTER THE M,NM,ML NOTES

3. HOUSEKEEPING
EXTRA CREDIT IS DUE TODAY. PLEASE TURN IT INTO THE BLACK BOX IF YOU DID IT.
WE WILL HAVE A NOTEBOOK CHECK NEXT MONDAY…WITH A QUIZ.
WE WILL HAVE A LAB TOMORROW…

4. DATA TALK 4TH- 76 5TH- 75 6TH- 78 7TH- 78 8TH- 77
OVERALL CLASS AVERAGE:
77%
USA TEST PREP RECOVERY IS ONLINE AND READY TO GO. SAME AS LAST TIME, 80% OR BETTER, UNLIMITED TRIES. DUE NEXT MONDAY OCTOBER 30.
52% of students made 80% or better 

6. We’ve talked about changes in matter…
The evaporation of a puddle of water
Rust forming on a metal fence
PHYSICAL
CHEMICAL

7. HOWEVER… No matter is created or destroyed by such changes!
The total amount of matter remains constant.

8. The Law of Conservation of Matter
During a chemical reaction, matter cannot be created or destroyed.
Even though the matter may change from one form to another, the same number of atoms exists before and after the change takes place!

10. Since the overall mass of the matter does not change…
The mass of the reactants – the substances there before the reaction occurs – must equal the mass of the product – the substances there after the reaction takes place.
Mass of
Reactants
Mass of
Products

11. NUMBERS IN EQUATIONS

14. The Formation of Rust Iron Rust Hard, gray-colored metal
Flaky, orange-red solid

15. When iron reacts with oxygen in the air, they form rust or IRON OXIDE.
This is written as:
Iron + Oxygen Iron Oxide

16. TAKE A LOOK AT THE NUMBERS
Each made of TWO oxygen atoms Fe Fe O2
Fe2O3
Fe2O3 Fe Fe O2 O2
2Fe 3O 2Fe 3O
4 Fe
6 O
REACTANTS
Totals
4 Fe
6 O
PRODUCTS

17. All Chemical Reactions follow the Law of Conservation of Matter
With Iron Oxide, the MASS STAYS THE SAME!
The total number of iron atoms and oxygen atoms in the reactants is the same as that in the product.
The atoms were just rearranged!
No new atoms were created and none were destroyed!

18. Determining the Mass of Reactants and Products
REMEMBER: The mass of the reactants is always equal to the mass of the products.
Mass of
Reactants
Mass of
Products

19. Example: Tin Fluoride
Tin + hydrogen fluoride -> tin fluoride + hydrogen
What’s the total mass of the reactants? g
So what should the mass of the products be?
118.7 g
40.02 g

20. Total Mass of Reactants: 158.72 g
Tin + hydrogen fluoride -> tin fluoride + hydrogen
If we know the mass of the tin fluoride, can we figure out how much hydrogen was produced?
Subtract the mass of one product from the total mass. g
2.01 g
Total Mass of Reactants: g

21. Please complete the LCM worksheet
Please take the next 5 minutes to read the background information.
This will go on pg. 52 in IAN
You then need to answer the 4 experiments and answer the short answer.
Please answer the short answer under your worksheet on pg. 52.
Whatever is not completed in class will be homework. This will be a graded assignment.