1. Oxidation Reduction

2. Redox OIL of electrons RIG of electrons Oxidation Is Loss Reduction Is
Gain
of electrons

3. Rxns
Oxidation
Mg(s) + S(s) MgS(s)
Reduction

4. Cont Mg(s) + S(s) MgS(s)
Reducing agent – substance in redox rxn that loses electrons is called a reducing agent.
Oxidation
Mg(s) + S(s) MgS(s)
Reducing Agent
Reduction

5. Cont. Mg(s) + S(s) MgS(s)
Oxidizing agent – substance in redox rxn that accepts electrons is called an oxidizing agent.
Oxidation
Mg(s) + S(s) MgS(s)
Reduction
Oxidizing Agent

6. Assigning Oxidation #’s
Rules
Monatomic ion = to ionic charge
Hydrogen (in compound) Metal Hydrides –1 (NaH)
Oxygen (in compound) – Peroxides –1 (H2O2)
Oxidation # of an atom in elemental form = 0

7. Cont. Neutral compound must = 0
Polyatomic ion – sum of oxidation #’s must = ionic charge

8. Half Reactions
Way of showing either the reduction or the oxidation of a species in an redox reaction.

9. Acid Half RXN
Step 1: Write the unbalanced equation in ionic form

10. Cont.
Step 2: Write separate rxns for the oxidation and reduction processes

11. Cont.
Step 3: Balance the atoms in the half-rxns

12. Cont.
Step 4: Balance charges

13. Cont.
Step 5: Multiply each half-rxn by the appropriate number

14. Cont.
Step 6: Add the half rxns

15. Base Half RXN
Step 1: Write the unbalanced equation in ionic form

16. Cont.
Step 2: Write separate half-reactions for the oxidation and reduction processes

17. Cont.
Step 3: Balance the atoms

18. Cont.
Step 4: Balance charges

19. Cont.
Step 5: Multiply each half reaction by the appropriate number

20. Cont.
Step 6: Add the half reactions

21. Practice!!!!!!!