building REDOX tables

Disproportionation Reactions

reaction where same species is oxidized and reduced

OA and RA substances

• a material that is both an OA and an RA

• may react with itself to produce two different substances

Balancing Disproportionation Reactions

• write oxidation numbers

• increase or decrease in oxidation numbers

• identify oxidized and reduced and write half reaction (add electrons)

• balance hydrogen and oxygen

• check atom and charge balancing

Electronegativity

tendency of an atom or molecule to attract electrons

table of selected electrode potential

• left side: oxidation agent (gain electron)

• right side: reducing agent (lose electron)

top of table of selected electrode potential

• strongest OA

• weakest RA

bottom of table of selected electrode potential

• weakest OA

• strongest RA

positive Eº

• easily reduced

• better OA

negative Eº

• easily oxidized

• better RA

Spontaneity Rule

• oxidizing agent must be above the reducing agents

• left hand above right hand

spontaneous REDOX reaction

• standard electrode potential for the REDOX reaction is positive

• E°_{(REDOX Reaction)} = E°_{(Reduction ½ Reaction)} + E°_{(Oxidation ½ Reaction)}

• E°_{(REDOX Reaction)} = E°_{(Cathode/SOA)} – E°_(Anode/SRA)

Building a REDOX table

• look for gain/loss of electrons

• spontaneous: OA above RA

• non-spontaneous: RA above OA

oxidation agent

• metal ions (cation)

• non-metal atoms (polyatomic)

reducing agent

• metal atom (monoatomic)

• nonmetal/polatomic ion (anions)