1. Acids, Bases and pH

2. Acids, Bases & pH H2O  H+ + OH-
1 water molecule in 550 million naturally dissociates (ionizes) into a Hydrogen Ion and a Hydroxide Ion
Hydrogen Ion Hydroxide Ion
Acid Base
H2O  H+ + OH-

3. Acids, Bases and pH pH = “potential of Hydrogen” pH scale 0-14
Each increase of one on the pH Scale = a 10x increase in the hydrogen ions in the solution
more H+ = more acidic = LOWER pH
More OH- = more basic = HIGHER pH

4. Acidity (pH) pH 7 = neutral – H+ and OH- exactly balanced
pH = ACID
Taste sour
ex. fruit juices
pH 7.01 to 14.0 = BASE
Taste bitter
Feel slippery
ex. soaps, bleach
Farther away from 7 - stronger
Most life needs close to neutral, between pH 6 & 8

5. Buffers
Weak acids / bases that react with strong acids / bases to prevent sharp, sudden changes in pH
You have buffers in your body!
Weak Acid
Weak Base

6. Some Examples of Acidity
Gastric Fluid = ~1.2 pH
Lemon Juice = ~2.1 pH
Orange Juice = ~3.6 pH
Rain* = ~ 5.8 pH
Distilled H2O = 7.0 pH
Blood = ~ 7.2 pH
Seawater = ~8.0 pH
Ammonia = ~ 12.8 pH
Lye = ~13.5 pH

7. Atoms, Molecules and Bonds
Atom: smallest particle of an element
protons (+)
electrons (-)
neutrons (no charge)
Element: many of the same atoms
Examples: Carbon, Hydrogen, Oxygen, Gold, Lead.

8. Atoms, Molecules and Bonds
Compound/Molecule: Atoms combined by the formation of bonds
Example: H2O, C6H12O6
Bond: Hold atoms together
Release energy when broken
More bonds = more energy
Example: Food energy, gasoline

9. Atoms, Molecules and Bonds
Three Types of Bonds
Ionic: One atoms gives electrons to another
Weak bond
Dissolve in water
ex. NaCl
Covalent: Atoms share electrons
Hold molecules together
Way strong
ex. O2, H2O
Hydrogen:
Weak
Break easily
ex. Between H2O molecules, within proteins