1. Acids & Bases

2. pH
pH of a solution is a measure of its hydronium ion (H3O+) concentration
0-14 number scale
7= Neutral
Below 7 = Acid
Above 7 = Base

3. pH Scale

4. Strength of Acids & Bases
The strength of an acid or base solution depends on how completely a compound is pulled apart to form ions when dissolved in water. This is called the degree of dissociation or ionization.

5. Strong pH Water is neutral Closer to 0, the stronger the acid
Strong acids: hydrochloric, sulfuric, nitric
Closer to 14, the stronger the base
Strong bases: sodium hydroxide, potassium hydroxide

6. Weak pH Weak pH is NEAR the neutral zone (pH =7)
Weak acids: acetic, carbonic
Weak bases: ammonia, aluminum hydroxide, iron hydroxide

7. Acids
A compound that produces Hydronium ions (H30+) or Hydrogen ions (H+) in water.
Acids donate protons
Example: HCl + H2O → H30+ + Cl-
The reactant HCl is known as hydrochloric acid

8. Common Acids CH3COOH Acetic acid Vinegar H2CO3 Carbonic acid
Carbonated drinks
HCl
Hydrochloric acid
Digestive juices in stomach
HNO3
Nitric acid
Fertilizer producer
H3PO4
Phosphoric acid
H2SO4
Sulfuric acid
Car batteries

9. General properties of Acids
Sour taste
Contain Hydrogen
React with metals to produce H gas
React with bases to produce salt & water
Corrosive
Electrolytes (will conduct electricity)

10. Base
A compound that produces hydroxide ions (OH-) when dissolved in water.
Ex. NaOH → Na+ + OH-

11. Properties of Bases Bitter Taste feel slippery to skin
Reacts with acids to produce salt & water
electrolytes
Don’t usually react with metals

12. Common Bases Ca(OH)2 Aluminum hydroxide Al(OH)3 Deodorant, antacids
Calcium hydroxide
Ca(OH)2
Concrete, Plaster
Magnesium Hydroxide
Mg(OH)2
Antacid, laxatives
Sodium hydroxide
NaOH
Drain cleaner, soap production

13. Always be careful when using acid/base Acid damage Base damage

15. Indicators
Indicator is substance that changes color in the presence of an acid or base
In acid, blue litmus paper turns red & phenolphthalein is colorless
In a base, red litmus paper turns blue & phenolphthalein is pink
Common indicators
Examples: litmus paper, pH meter, pH paper, and phenolphthalein.

16. Formation of Salts
Salt- Compound formed from positive ion of a base and a negative ion of an acid
Acid + Base
Is a neutral substance

17. Neutralization
Reaction of an acid with a base to produce a salt and water (double replacement)
HCl + NaOH → H2O + NaCl
Whenever deciding if it is a neutralization reaction, look for H2O and a salt, such as NaCl, on the right side of arrow