1. U4 S1 L1 Defining Oxidation and reduction Textbook Readings MHR page 712: Oxidation-Reduction Reactions pages 713-715: Defining Oxidation and Reduction pages 715-716: Half Reactions Textbook Practice Items MHR page 715: items 1, 2, 3 and 4 page 716: items 5, 6, 7 and 8 page 720: items 1, 2, 3, 4, 5 and 6 LEO & Mervin OIL RIG

2. Upon completion of this lesson, you should be able to: define oxidation and reduction in terms or loss or gain of electrons identify electron transfer in redox equations state that a chemical entity loses electrons when it is oxidized and that a chemical entity gains electrons when it is reduced identify oxidation and reduction half-reaction equations in an oxidation reduction (redox) equation identify a redox equation as the sum of the oxidation half-reaction and the reduction half-reaction identify the species oxidized, the species reduced, the oxidizing agent, and the reducing agent in simple redox equations

3. Oxidation-reduction reactions involve the transfer of electrons from one species to another. The species that loses electrons is said to be oxidized The species that gains electrons is said to be reduced In order for an oxidation-reduction reaction to take place, we need both process to occur. That is, we cannot have oxidation with out reduction. Why not? LEO is an OX –Loss of Electrons is Oxidation OIL RIG Oxidation Is LossReduction Is Gain

4. Interpret using a Lewis dot diagram:

5. Net ionic equations: Write a net ionic equation for the reaction of solid zinc and an aqueous solution of copper (II) sulphate. Word equation: Balanced Chemical equation: Total Ionic equation Net ionic equation

6. Zn (s) + Cu 2+ (aq) →Zn 2+ (aq) + Cu (s) Half reactions: Zn (s) → Zn 2+ (aq) + 2 e - Zn(s) lost 2 electrons (thus Zn(s) was oxidized.) Cu 2+ (aq) + 2 e- → Cu(s) Cu 2+ gained 2 electrons (thus Cu 2+ was reduced.) In this case, the electrons were transferred from zinc to copper. –Zn(s) was oxidized by Cu 2+ so we say that Cu 2+ was an oxidizing agent. the oxidizing agent is the species causes the the oxidation (it gets reduced) –Similarly we can say that Zn(s) was acting as the reducing agent. the reducing agent is the species that causes the reduction (it gets oxidized) Why?

7. Write a net ionic equation and half reactions for the reaction of magnesium with aqueous aluminum sulphate. Identify the species oxidized, reduced, the reducing agent and the oxidizing agent.

8. Disproportionation reaction: –An oxidation reduction reaction in which a single species is both oxidized and reduced.