1. Acids & Bases

2. Arrhenius definition of Acids & Bases
Acid: substance that contains hydrogen and ionizes to produce hydrogen ions in aqueous solutions Base: substance that contains a hydroxide group and dissociates (breaks down) to produce a hydroxide ion in aqueous solution

3. Examples of Arrhenius Acids & Bases
Arrhenius Acid Equation: HCl (g)  H+ (aq) + Cl- (aq) Arrhenius Base Equation: NaOH (s)  Na+ (aq) + OH- (aq)

4. Other Models of Acids & Bases
Bronsted-Lowry Model An acid is a hydrogen-ion donor; a base is a hydrogen-ion acceptor Lewis Model A Lewis acid is an electron-pair acceptor and a Lewis base is an electron-pair donor

5. Common Properties of Acids
Produce H+ ions in water (the hydronium ion is a hydrogen ion attached to a water molecule)
Taste is sour
Corrodes metal
Electrolytic
Reacts with bases to form salt and water
pH is less than 7
Turns blue litmus paper to red

6. Common Properties of Bases
Produce OH- ions in water
Bitter, chalky taste
Electrolytes
Feel soapy, slippery
React with acids to form salts and water
pH greater than 7
Turns red litmus paper blue

7. pH of Common Substances

8. pH Testing Possibilities
Blue litmus paper (red = acid)
Red litmus paper (blue = acid)

9. pH hydrion paper (multi-colored)
pH meter (7 neutral, <7 acid, >7 base)
Universal indicator (multi-colored)

10. Indicators like phenolphthalein (purple-pink in presence of a base)
Natural indicators like red cabbage, radishes

11. Acid/Base Titration
A titration is a carefully controlled neutralization reaction.
You have a solution of an unknown concentration of an acid or base & a second solution of known concentration called your standard solution.
The goal is to find the end point (the total moles of H+ donated by acid is equal to the total moles of H+ accepted by the base)