1. Measuring acids and basespH
Measuring acids and bases

2. The pH scale is used to measure the strength of acids and bases
pH: What is it?
The pH scale is used to measure the strength of acids and bases

3. H2O H+ + OH-   pH: What is it?
Some compounds break up into ions when they dissolve in water.
Solutions with more H+ ions are more ACIDIC
They have a LOW pH
Solutions with less H+ ions are more BASIC
They have a HIGH pH 
H2O H OH- 

4. Some properties of acids and bases
pH: What is it?
Some properties of acids and bases pH
Example
Characteristics
Acids
Neutral
Bases
Lemon vinegar soda, aspirin
Sour, burns, dissolves things
< 7
Pure Water
------
= 7
Soap,
baking soda, ammonia
> 7
Bitter, Slippery

5. pH: Looking at common items
Battery Acid
pH = 0
Orange Juice
pH = 3
Ocean Water
pH = 8
Oven Cleaner
pH = 13

6. pH: Importance to Humans
Blood has a pH of 7.4 (about neutral)
If pH goes below 6.8 or above 7.8 it is deadly!
To keep blood at the proper pH - our body uses buffers

8. pH: Buffers
Buffers are weak acids or weak bases that neutralize, or weaken, strong acids or bases.
In blood, buffers prevent pH change.
Sodium bicarbonate, or baking soda, is a buffer