1. Acids and bases
Lesson 1

2. Acids
Although some acids can burn and are dangerous to handle, most acids in foods are safe to eat.
What acids have in common, however, is that they contain at least one hydrogen atom that can be removed when the acid is dissolved in water.

3. Acids
An acid is a substance that produces hydrogen ions H+ in a water solution. It is the ability to produce these ions that gives acids their characteristic properties
When an acid dissolves in water, H+ ions interact with water molecules to form H3O+ ions, which are called hydronium ions.

4. HCl + H2O  H3O+ + Cl– Definitions Acids
Ionize to form hydronium ions (H3O+) in water
HCl + H2O  H3O+ + Cl–

5. Dissociation of Acids
When hydrogen chloride (HCl) dissolves in water, a hydronium ion and a chloride ion are produced.

6. Common Acids
At least four acids (sulfuric, phosphoric, nitric, and hydrochloric ) play vital roles in industrial applications.

7. Bases
Any substance that forms hydroxide ions, OH, in a water solution is a base.
In addition, a base is any substance that accepts H+ from acids.
They are the opposite of acids.

8. NH3 + H2O  NH4+ + OH- Definitions Bases
Dissociate or ionize to form hydroxide ions (OH-) in water
NH3 + H2O  NH4+ + OH-

9. Dissociation of Bases
The base dissociates into a positive ion and a negative iona hydroxide ion (OH).

10. Dissociation of Bases
Unlike acid dissociation, water molecules do not combine with the ions formed from the base.

11. Ammonia Ammonia is a base that does not contain –OH.
In a water solution dissociation takes place when the ammonia molecule attracts a hydrogen ion from a water molecule, forming an ammonium ion (NH4+). This leaves a hydroxide ion (OH).

12. Common Bases
You probably are familiar with many common bases because they are found in cleaning products used in the home.

13. Common Bases
Some drain cleaners contain NaOH, which dissolves grease, and small pieces of aluminum.
The aluminum reacts with NaOH, producing hydrogen and dislodging solids, such as hair.

15. Definitions Indicator
Organic substance that changes color in an acid or base
Examples:
litmus - red/blue
phenolphthalein - colorless/pink
goldenrod - yellow/red
red cabbage juice - pink/green

16. Properties ACIDS BASES sour taste corrosive electrolytes
turn litmus red
react with metals to form H2 gas
bitter taste
corrosive
electrolytes
turn litmus blue
slippery feel

17. Uses ACIDS H3PO4 - soft drinks, fertilizer, detergents
H2SO4 - fertilizer, car batteries
HCl - gastric juice
HC2H3O2 - vinegar

18. Uses BASES NaOH - lye, drain and oven cleaner
Mg(OH)2 - laxative, antacid
NH3 - cleaners, fertilizer