1. Daily Science
____Na + ____H2O ____NaOH + ____H2

2. The pH Scale
Biology 1

3. Draw a rough sketch of the pH scale as shown below

4. The pH scale
Scientists made this to indicate the concentration of H+ ions in a solution
Ranges from 0-14
pH of 7 = neutral
pH below 7 = acidic
pH above 7 = basic

5. The pH of pure water
In water the number of positive hydrogen ions equals the number of negative hydroxide ions
Making the pH of pure water neutral
H2O H OH-
Water hydrogen ion + hydroxide ion

6. Hydroxide and Hydrogen ion Concentrations
More H+ ions
Each step represents a factor of 10
More OH- ions

7. Acids Acid- any compound that forms H+ ions in a solution
pH values below 7
Example: stomach acid has a pH of 1-3

8. Bases Base- a compound that produces hydroxide ions (OH-) in solution
Also known as alkaline solutions
Have low concentrations of hydrogen ions (H+)
Example: oven cleaner has a pH of 11-14

9. Buffers
Buffers- are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
Example: fluids within most cells contain buffers
This helps to keep the pH between
What would happen to your body’s cells if the pH became too high or too low?
Answer: Would not have homeostasis, would destroy cell

10. Acidosis Excessive acid in body fluids
Caused by alcohol, cancer, too much CO2 or lactic acid in the body