1. Acids and Bases
Bundle 4: Water

2. What is an Acid?
An acid is any species that increases the concentration of H+ ions in a solution.

3. pH is a measure of how much H+ ions are present
0 – 6 pH is Acidic
7 = neutral solution

4. Acid
Excess H+
pH below 7
Low pH = Strong Acid

5. What is a Base?
A base is any species that increases the concentration of OH- ions in a solution.

6. pOH is a measure of how much OH- ions are present
8 – 14 pH is Basic
pOH values are opposite of pH values

7. Base
Excess OH-
pH above 7
High pH = Strong Base

8. pH and pOH =14

9. Calculating Acid Relationship
For each ONE UNIT step you go down in pH, the solution is 10 times more acidic.
For each ONE UNIT step you go up in pH, the solution is 10 times less acidic.

10. Calculating Base Relationship
For each ONE UNIT step you go down in pOH, the solution is 10 times more basic.
For each ONE UNIT step you go up in pOH, the solution is 10 times less basic.

11. Examples
How many times more acidic is a solution with pH of 3 than a solution with the pH of 6?
10 x 10 x 10 = 10,000 times more acidic
How many times less acidic is a solution with pH of 5 than a solution with the pH of 3?
10 x 10 = 100 times less acidic

12. Examples
How many times more basic is a solution with pH of 8 than a solution with the pH of 10?
10 x 10 = 100 times more basic
How many times less basic is a solution with pH of 13 than a solution with the pH of 9?
10 x 10 x 10 x 10 = 100,000 times less basic

13. What have you learned?
Is this solution more Acidic or more Basic or Neutral?
How do you know?

14. What have you learned?
Is this solution more Acidic or more Basic or Neutral?
How do you know?