1. Types of Reactions
Solutions Unit

2. Redox (Reduction/Oxidation)

3. Remember: LEO the lions says GERRRRRR!
What is Redox?
30/09/99
REDOX stands for REDuction/OXidation
Oxidation is often thought of as a combination of a substance with oxygen (rusting, burning)
Oxidation refers to a loss of e-
Reduction refers to a gain of e-
Remember: LEO the lions says GERRRRRR!
Loss Electrons = Oxidation
Gain Electrons = Reduction

4. Reactions Fe --> Fe+3 +3e- What is happening to the Fe atom?
Fe is going from 0 to +3 oxidation #
It must be losing electrons
Loss of Electrons = Oxidation
In conclusion, the iron atom is being oxidized

5. In conclusion, the sulfur atom is being reduced
Reactions
S +2e- --> S-2
What is happening to the Sulfur atom?
S is going from 0 to -2 oxidation #
It must be gaining electrons
Gain of Electrons = Reduction
In conclusion, the sulfur atom is being reduced

6. Acid/Base Reactions

7. Neutralization In general: Acid + Base  Salt + Water
All neutralization reactions are double displacement reactions.
HCl NaOH  NaCl HOH

8. Precipitation Reaction
Reactions that form a precipitate
Precipitation Reaction

9. Definition:
Precipitate: A solid that forms as the result of a chemical reaction in aqueous solution.

10. Precipitation Reaction:
A reaction in which a solid is formed from a solution is called a precipitation reaction
Solid = precipitate = insoluble

11. Solubility – Why does it matter?
A precipitation reaction only occurs if one of the products is insoluble.