1. Acids, Bases and pH
GLE and 9.4.5

2. Why should we study pH?
pH affects many things both chemically and biologically.
For example: swimming pools, fish, soil and chemical reactions in their own bodies.
Example: Blood pH
pH of blood must stay within a narrow range, usually about 7.4
Buffers (bicarboate ions) maintain your blood at an almost constant pH
If pH of blood varies by more than 0.4, death can result

3. What is pH?
pH is a measure of the acidity or alkalinity of a substance.
A pH lower than 7 is ACIDIC.
A pH greater than 7 is BASIC or Alkaline.
A pH of 7 is NEUTRAL

4. What is an acid?
An acid is a substance that produces hydrogen ions in a water solution.
Interaction of H+ with water produces HYDRONIUM ions: H3O+

5. What is a Base?
A base is any substance that produces hydroxide ions, OH-, in a water solution, OR any substance that accepts H+ from acids

6. Let’s Review!
___________ maintain your blood level in order to maintain a certain pH.
__________ produce hydronium ions in water.
__________ produce hydroxide in water.
A pH of _____ is neutral.

7. Let’s Review!
Buffers maintain your blood level in order to maintain a certain pH.
Acids produce hydronium ions in water.
Bases produce hydroxide in water.
A pH of _7_ is neutral.