1. Chemical Reactions and Changes
How do you know if a chemical change has taken place?
Chemical Reactions occur when:
Involve the rearrangement of atoms

2. Chemical Equations ___________are used to write chemical equations.
The chemical compounds used to start the reaction are called the:
The chemical compounds at the end of the of the reaction are called the:

3. + Reaction Symbols There are several types of Reaction symbols used. 
g –
s –
l –
Aq—

4. Law of Conservation of Mass
Matter cannot be :
It is always conserved in a reaction.
Atoms cannot simply appear or disappear.

5. Practice Counting Atoms
Mg=
Mg(NO3)2
MgCl2
Cl = H=
(NH4)3PO4
H2SO4 S= O=

6. Balanced Equations
In order to conserve atoms, we must balance the number and type of atoms.
CAN’T CHANGE _______________!
Can only change the numbers of atoms on each side of the equation by adding coefficients.
Coefficients:

7. Let’s Try to Figure out Coefficients
How many atoms of each do you have?
3 H20
2 H2O3
4 Fe2O3

8. Steps to Balancing First:
If there are different numbers of atoms for an element on both sides, you must:

9. Second, figure out what coefficient is needed in order to make the smaller number equal to the larger number.
REMEMBER: IF YOU CHANGE A COEFFICIENT:

10. ___C + ___Cl2  ____CCl4 ___Al2O3  ___ Al + ___ O2
Magnesium + Oxygen (g)  Magnesium Oxide
___C + ___Cl2  ____CCl4
___Al2O3  ___ Al + ___ O2

11. Helpful Hints to Balancing
If an element appears in more than one compound on the same side of the equation. (Combustion Reactions)
__C2H4 + __O2  __CO2 + __H2O
If there is an even number of atoms on one side and an odd number on the other side, put a coefficient of 2 in front of the ODD compound.

12. Exothermic v. Endothermic
Exothermic reactions: so the temperature _______
Endothermic reactions: so the temperature___________

13. Addition (Synthesis)
Decomposition

14. Single Replacement
Double Replacement

15. Combustion
Acid Base

16. Let’s practice- Type _______ HgO → Hg + O2
_______ CH4 + O2 → CO2 + H2O
_______ NaCl + AgNO3 → NaNO3 + AgCl
_______ Mg + HCl → MgCl2 + H2
_______ Zn + H2SO4 → ZnSO4 + H2
_______ C6H12O6 + O2→ CO2 + H2O
_______ NaOH + HCl → NaCl + H2O
_______ Al2(SO4)3 + Ca(OH)2 → Al(OH)3 + CaSO4
_______ H2 + O2 → H2O
_______ Cl2 + NaBr → NaCl + Br2
_______ KClO3 → KCl + O2
_______ C2H2 + O2→ CO2 + H2O
_______ Na2O + CO2 → Na2CO3

17. Categorizing Chemical Reactions
All chemical reactions involve something moving, so we can categorize the types of reactions we just learned to help us predict the products in a reaction!
Moving electrons =
Moving ions =
Moving protons =

18. Mg + Br2  MgBr2
In the first example, think about the Lewis Structures that we’ve drawn.
The Magnesium atom:
There is a:

19. NaCl  Na + Cl2
In the second example:

20. Zn + CuSO4  Cu + ZnSO4 During this reaction:
Now that Zn+2 has a charge, it will form:

21. Reduction and Oxidation Reactions
A substance that is reduced:
A substance that is oxidized:
OIL RIG
LEO the lion says GER

22. And now, the tricky part…
A substance that has been oxidized is called:
A substance that has been reduced is called:

23. Br starts with 0 charge and ends with -1
Mg starts with 0 charge and ends with +2
This means Br has been ______ and is the _______ agent.
This means Mg has been ______ and is the _______ agent.

24. Na starts with a +1 charge, ends with 0 charge
Cl starts with a -1 charge, ends with 0 charge
This means Na has been _______ and is the _______ agent.
This means Cl has been _______ and is the _______ agent.

25. Zn Cu SO4 Zn started with 0 charge, ended with +2
Cu started with +2 charge, ended with 0
SO4 started and ended with -2, no electrons changed here Zn Cu
SO4