1. Acids and Bases

2. Acids: sour-tasting, water-soluble substances that are found in many common products.
They are so reactive that they can combine with many other substances!
Acids are good conductors of electricity!
Important in the chemical industry:
Example: sulfuric acid. Used in manufacturing fertilizers and explosives, refining oil, etc.

3. Examples of acids: Common Name Formula Source or Use
Vinegar (acetic acid)
HC2H3O2
Salad dressings
Citric Acid
HC6H7O7
Oranges, Lemons
Ascorbic Acid
HC6H7O6
Vitamin C
Lactic Acid
HC3H5O3
Sour milk
Carbonic Acid
H2CO3
Carbonated drinks
Acetylsalicylic Acid
HC9H7O4
Aspirin
Sulfuric Acid
H2SO4
Car batteries

4. Bases: bitter-tasting, water-soluble substances that feel slippery when in aqueous solution
Also described as alkaline
Bases are good conductors of electricity!
Bases react with proteins to break them down into smaller molecules:
Example: Drain cleaner can fix a drain clogged with hair, because the base breaks down the protein in the hair!

5. Ammonia window cleaner (Windex)
Examples of bases:
Common Name
Formula
Source or Use
Sodium hydroxide
NaOH
Drain cleaner
Potassium hydroxide
KOH
Soap, cosmetics
Aluminum hydroxide
Al(OH)3
Antacids
Ammonium hydroxide
NH4OH
Ammonia window cleaner (Windex)
Sodium bicarbonate
NaHCO3
Baking soda
Potassium sulfite
K2SO3
Food preservative

6. The pH Scale
Scientists use the pH scale to represent how acidic or basic a solution is.
A very acidic solution has a very low pH value (0-5)
A neutral solution, like pure water, has a pH of 7
A very basic (alkaline) solution has a very high pH value (8-14)

8. pH and Soil Plants differ in their preference for soil acidity!
Sources of soil acidity include organic matter decay, naturally occurring acids, and acid precipitation.
Lime (CaO) can be added to acidic soil to make the soil more basic.

9. pH and Cosmetics
The acidity of a shampoo can have a definite effect on hair!
The clear outer protein layer of hair is the cuticle. If a shampoo is basic, it can start breaking down the cuticle.

10. The pH of soaps and other cosmetic products can also affect skin cells.
The pH of skin normally ranges between 5-6. Using basic products can remove the outer layer of dead skin cells!
Hyperlink to pH balancing cleansers