1. Acids and Bases
Pg. 119

2. Properties of acids and bases
Acidic solutions taste sour
Blue litmus paper turns pink when dipped in an acidic solution
Basic solutions taste bitter and feel slippery
Red litmus paper turns blue when dipped in a basic solution

3. What makes a solution an acid or a base?
All solutions in water contain H ions (H+) and hydroxide ions (OH-)
An acidic solution contains more hydrogen ions
A basic solution contains more hydroxide ions
Neutral solutions contain equal amounts
Also use hydronium ions to represent acids (H3O+)

4. Arrhenius model of Acids and Bases
Acid is a substance that contains hydrogen and ionizes to produce hydrogen ions in an aqueous soution
Base is a substance that contains hydroxide group and dissociates to produce a hydroxide ion in aqueous solutions
Ex Acidic solution : HCl  H+ + Cl-
Ex Basic solution: NaOH Na+ + OH-

5. Bronsted- Lowry model
Says an acid is a hydrogen-ion donor and a base is a hydrogen-ion acceptor
HX (aq) + H2O (l) H3O+ (aq) + X- (aq)
An acid reacting with a base produces a conjugate acid and a conjugate base
Conjugate acid is the species that accepts a H+ from an acid
Conjugate base is the species that results when an acid gives up a H+.
conjugatebase
acid
base
Conjugate acid

6. Examples identifying acids and bases
NH3 (aq) + H2O (l) NH4+ (aq) + OH- (aq)
HBr (aq) + H2O H3O+ (aq) + Br –(aq)

7. Types of acids and bases
Water and a few other substances can act as both an acid and a base  called amphoteric
Acids that completely ionize are strong acids
HCl
HBr HI
HNO3
HClO4
H2SO4
Acids that ionize partially are weak acids
Strong bases dissociate into metal ions and hydroxide

8. Measuring acids and bases
Use the pH scale
0-7 = acidic
7-14 = basic
7 is neutral

9. Neutralization Acid and a base react to form water and a salt
Ex. Mg(OH)2 + 2 HCl  MgCl2 +2 H2O
Use titration to determine the concentration at which the solution is neutral