1. NOTES #5: Oxidizing & Reducing Reactions
WCHS Chemistry
**NEED PERIODIC TABLE & ION SHEET**

2. INTRO: Classify the following...
Pb S-2 NH Fe2S3
H2SO4 O2 LiOH Ca
Cr Al+3 Cl KNO3
ELEMENTS IONS COMPOUNDS
NEUTRAL
CHARGED
NEUTRAL
Pb Cr O2 Cl2 Ca
NH4+1 Al+3 S-2
Fe2S3 H2SO4 LiOH KNO3

3. KEY IDEAS
An element has a neutral charge
Ex: Mg0 and O20
An ion has a charge - BUT is IN a compound
Ex: Mg+2 (MgCl2)
Compounds have an overall NEUTRAL charge!!!
Ex: MgO

4. DIATOMIC ELEMENTS
HOFBrINCl
H2 O2 F2 Br2 I2 N2 Cl2
DON’T FORGET! :)

5. OXIDATION REDUCTION REACTIONS
Some chemical reaction involve changing the charge on a substance!
-1 -1 +2
Ca + Br2 → CaBr2 →
ELEMENT
ELEMENT
COMPOUND
Oxidation occurs when the ionic charge increases Ca Ca +2
Redcuction occurs when the ionic charge decreases -1 Br Br
WE ONLY CARE ABOUT ONE ATOM!!

6. OXIDATION REDUCTION REACTIONS+2 -2 +2 -2
CaSO4 + Mg → MgSO4 + Ca →
Oxidation = charge increases Mg Mg +2
Redcuction = charge decreases Ca Ca +2
SO4-2 → SO4-2
= spectator ion (stays the same)