Electrochemistry- Term 1, Year 12

Electricity
1. The flow of electrons
2. Measured in Volts
Electron transfer reactions/Redox
1. Oxidation
  1. Loss of electrons
  2. Oxidising agent
    1. Electron acceptor
    2. Is reduced
2. Reduction
  1. Gain of electrons
  2. Reducing agent
    1. Electron donor
    2. Is oxidised
Oxidation Numbers
1. 1. Element = 0
2. 2. Monoatomic ion = 0
3. 3. Oxygen -2, peroxide -1
4. 4. Hydrogen +1, metal hydride -1
5. 5. Sum ON compound = 0
6. 6. Sum ON polyatmoic ion = charge
7. Increase indicates loss of electrons
8. Decrease indicates gain of electrons
Balancing Redox Equations
1. Oxidation Number Change Method
2. The Half Reaction Method
  1. Acidic solution
  2. Basic solution
Galvanic/Voltaic Cell
1. Salt bridge
  1. KCl - Potassium Chloride
2. Electrodes
  1. Anode
  2. Cathode
3. Electrolyte
4. Cell Potential
  1. Also called ElectroMotive Force (emf)
  2. Ecell = Reduction Potential + Oxidation Potential
  3. Calculated under standard conditions
    1. 25 degrees Celsius
    2. 1 atm of pressure for all gases
    3. 1M concentration for all ions
Corrosion
1. Rusting - Iron
  1. 1. Iron atoms to Iron (II) ions
  2. 2. Iron (II) ions to Iron (III) ions
2. Loss of electrons
3. Dry corrosion
4. Wet corrosion
5. Preventatives
  1. Physical Protection
    1. Paint
    2. Oil or grease
    3. Plastic coating
    4. Tin plating
    5. Galvanising
    6. Electroplating
    7. Cathodic Protection
  2. Chemical Protection
    1. Sacrificial Protection
    2. Alloying

Resource summary

	Created by Valerie Shepherd about 10 years ago