1. Acids, Bases, and pH

2. pH- measure of the acidity or alkalinity of a substance
Acidity- is cause by H+ (hydrogen ions)
Alkalinity (base)- is caused by OH- (hydroxide ions)

3. In pure water, there are equal amounts of hydronium (H+) and hydroxide ions (OH-)
Pure water is neutral

4. pH Scale- measurement system indicates H+ ions in a solution
Pure water is neutral or a 7 on the pH scale
The more hydrogen ions present, the more acidic
The more hydroxide present, the more alkalinity

5. pH Scale

6. pH Scale
As the pH number increases, the substance becomes more basic (alkaline) and has more hydroxide ions

7. pH Scale
As the pH number decreases, the substance becomes more acidic and has more hydronium ions

8. pH Scale
Remember: water is neutral and is 7 on the pH scale

9. pH Scale In the human body:
pH of fluids within most cells must be between 6.5 and 7 for chemical reactions to occur