1. Chem Catalyst Determine what is being oxidized and what is being reduced in the following reaction: CuO + H 2  Cu + H 2 O

2. Today’s Agenda: 1. Do Now 2. Notes- Writing half reactions 3. HW: Practice Worksheet

3. Half Reactions: - Show only oxidation or reduction - Include electrons gained or lost to balance charges - Losing electrons (oxidation): electrons appear as a product - Gaining electrons (reduction): electrons appear as a reactant

4. Half Reactions: - Add electrons to the following half reactions. Al  Al 3+ S 2-  S Cl  Cl - Sr  Sr 2+

5. Voltaic cell - Consists of 2 half-reactions - Cathode: where reduction occurs (RED CAT) - Anode: where oxidation occurs - Electrons flow from anode to cathode (electric current)

6. Voltaic cell

7. Cu/Zn Redox Reaction - Occurs spontaneously - E - flow from Zn to Cu - This flow of electrons creates an electrical current - http://www.youtube.com/watch?v=V7fS1 QofMqI http://www.youtube.com/watch?v=V7fS1 QofMqI

8. Voltaic Cell Summary: 1. Electrons are given off when zinc is oxidized (anode) 2. E - pass through wire to copper 3. Copper is reduced (cathode) 4. Ions move across salt bridge http://www.youtube.com/watch?v=nNG5PMl HSoA&feature=related