Base , Acid & Buffer

1. Lewis Theory Acid : the compound accepts electrons Base : the compound donates electrons

2. Arrhenius Theory Acid : when dissolved in water, it produces H + ions Base : when dissolved in water it produces H- ions

3. Arrhenius Theory Example : Acid : HaA → a H+ + A a- Base : M(OH)m → M m+

4. Buffer : a solution that can resist changes in pH.

5. The Example of Buffer : - CH3COOH mixture with NaCH3COO - NH4OH mixture with NH4Cl

6. When a small amount of a strong acid is added to the buffer solution, the pH of the solution changes slightly so that the change is negligible

7. When a small amount of a strong base is added to the buffer solution, the pH of the solution changes slightly so that the change is negligible

8. Bronsted - Lowry Acid : the compound donates protons Base : the compound accepts protons H+ = protons

9. Boyle Theory Acid : can change the color of blue litmus to red Base : can change the color of red litmus to blue

10. Bronsted Lowry H2O + H2O ⇄ H3O+ + HO- Base + Acid ⇄ conj. acid + conj. base

11. pH acid <7 pH base >7