8. Remember the acronym O.i.l.r.i.g.Oxidation is loss Reduction is Gain What is Oxidized and What is Reduced?
9. Steps to Balance A Half-Reaction Identify key element that undergoes an oxidation state change Balance the number of atoms for the key element Add electrons to compensate for oxidation state change Add H+ or OH- to balance charge Add H2O as needed to balance equation
10. Example Of Balancing a Half-Reaction Balance the two half reactions for the reaction in an acid solution H2O2 + I I2 + H2O First Identify what is being oxidized/reduced The Half-reaction 2I- I2 Shows Oxidation The Half-reaction H2O2 2H2O
11. Example Cont. Add Electrons to compensate for the changes in oxidation state For the Iodine reaction you must add two electrons to the products 2I- I2 + 2e- For the Oxygen reaction you must add two electrons to the reactants H2O2 + 2e- 2H2O
12. Example Cont. Add H+ or OH- to balance the charge In this case H+ should be added to the reduction half reaction, the balanced equations are as follows 2I- I2 + 2e- (oxidation) H2O2 + H+ + 2e- 2H2O (reduction)
19. Steps for Doing a Single Replacement Reaction Figure out if the reaction will occur by using the activity series Write reactions Write products Balance
20. Example of a Single Replacement Reaction Magnesium Metal + Aqueous Aluminum Chloride Figure out if the reaction will occur by looking at the activity series Magnesium is higher on the activity series than