Oxidation Reduction

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

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

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

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

Assigning Oxidation #’s Rules Monatomic ion = to ionic charge Hydrogen (in compound) +1 Metal Hydrides –1 (NaH) Oxygen (in compound) –2 Peroxides –1 (H2O2) Oxidation # of an atom in elemental form = 0

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

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

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

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

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

Cont. Step 4: Balance charges

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

Cont. Step 6: Add the half rxns

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

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

Cont. Step 3: Balance the atoms

Cont. Step 4: Balance charges

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

Cont. Step 6: Add the half reactions

Practice!!!!!!!