1. Topic: BASES Topic: BASES Do Now:

3. IDENTIFY a Base Covalent Formulas metal + OH (exception:NH 3 it’s a base too) Table L NOTWHY? CH 3 OH is NOT a base. WHY?

4. Bases Properties of Bases 1.Bitter taste 2.Slippery or soapy feeling 3.Electrolytes –NaOH  Na + (aq) + OH - (aq) 4.React with acids to produce water and salt 5.Bb 5.Bases turn litmus blue

5. Arrhenius Base substance that contains hydroxide group & ionizes to produce OH -1 ions in aqueous solutionsubstance that contains hydroxide group & ionizes to produce OH -1 ions in aqueous solution OH -1 NaOH(s)  Na +1 (aq) + OH -1 (aq)

6. THERE IS A LIMITATION TO THIS MODEL… –NH 3 is a base but it doesn ’ t contain OH -1 but it produces OH -1 :NH 3 + H 2 O :NH 3 + H 2 O  NH 4 +1 + OH -1

7. Bronsted-Lowry Base Base = proton acceptorBase = proton acceptor OH -1 is base Not restricted to aqueous solutionNot restricted to aqueous solution NH 3 + H 2 O  NH 4 +1 + OH -1 NH 3 is a base!

8. Water is amphoteric! Amphoteric = Substance that acts as both acid & base

9. Naming Bases Name the metal + hydroxideName the metal + hydroxide NaOH = ? Ca(OH) 2 = ? Mg(OH) 2 = ? Sodium hydroxide Calcium hydroxide Magnesium hydroxide

10. Not all bases are created equal Strong bases 100% dissociate Group 1 and Group 2 metals + OH are considered Strong bases –NaOH  Na + (aq) + OH - (aq) Weak bases –NH 3

11. REVIEW Acids: start with H or end with COOH –Produces H + ions –Proton Donor Bases: metal + OH –Produces OH - ions –Proton Acceptor