1. Agenda 1/12/10 Pass back quiz and SSS lab. ????
Acids and Bases Notes (page #10 in packet).
pH Scale (page #11 in packet).
Common Acids and Bases (page #12 in packet).
Demo day (time permitting).
HOMEWORK:
None for tonight.
Remote Review Next Thursday.
Unit 5 Exam Next Friday.

2. Acids and Bases
Acid: a compound that contains the element hydrogen and when it is dissolved in water the hydrogen comes off the acid molecules and attaches to the water molecule.
Acids are called proton (H+) donors
Properties of Acids
Sour taste
Turns blue litmus paper red
Acids react with certain metals to give off hydrogen gas
Electrolytes
Corrosive

3. Examples of Acids HCl – hydrochloric acid (stomach)
H2SO4 – sulfuric acid (batteries)
HC2H3O2 – acetic acid (vinegar)
HNO3 - nitric acid (for manufacturing of explosives and fertilizers)
H3PO4 – phosphoric acid (acidifies foods and colas)
HC6H7O7 - citric acid (found in fruits)

4. Acids and Bases continued….
Base: a compound that contains OH and when it is dissolved in water the OH comes off the base molecule.
Properties of Bases
Feels slippery
Bitter taste
Turns red litmus paper blue
Corrosive
Dissolves fats and oils

5. Examples of Bases NaOH – (sodium hydroxide – soap and Drano)
Ca(OH)2 – calcium hydroxide
Baking Soda – NaOHCO2
Toothpaste - OH-CH2-CH2-O-CH2-CH OH

6. Indicators and pH Scale
Indicator: a substance that changes color in the presence of an acid or a base.

7. Examples of Indicators
Litmus Paper
red paper turns paper blue  base
blue paper turns paper red  acid
Phenolphthalein (PHTH)
paper turns pink = base
paper stays colorless = acid
Methyl Orange
paper turns red = acid
paper turns yellow = base

8. pH Scale
A number scale used to describe the strength of an acid or base.
The stronger the acid, the lower the pH.
The stronger the base, the higher the pH.
pH scale ranges from 1 – 14
pH scale 1 – 6 indicates an acid
pH scale 8 – 14 indicates a base
pH of 7 is neutral

9. pH Scales