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To design an electrochemical cell that produces an optimal energy output.,…

- - - - Generates electric current from spontaneous redox reactions
      - Fuel cells
        
        A specialised galvanic cells where fuel and oxidant are in continuous supply
        
        Primary cells: can't be recharged
        
        Secondary cells: rechargeable (reversible redox reactions through input of electrical energy)
        
        Examples:
        
        Phosphoric acid fuel cell
        
        Fuel (reductant): H2
        Oxidant: O2
        Anode: H2--> 2H+ + 2e-
        Cathode: O2 + 4H+ + 4e- --> 2H2O
        Net equation: 2H2 + O2 --> 2H2O
        
        Alkaline fuel cell
        
        Fuel: H2
        Oxidant: O2
        Anode: H2 + 2OH- --> 2H2O + 2e-
        Cathode: O2 + 2H2O + 4e- --> 4OH-
        Net equation: 2H2 + O2 --> 2H2O
        
        Energy output is constant as it never discharges
      - Chemical energy --> electrical energy b
      - Simple metal displacement reaction
      - Energy output decreases as cell runs down
    - - Non-spontaneous reactions ∴ need external electron source
- - - - Use LeChanterlier's principle to get qualitative data
  - - - Electrolytic cell
        
        Equivalence between electricity and mass; more electricity applied to a cell, link to the mass that cathode or anode gain or lose
        
        Mass loss is equivalent to the equivalent weight of the cathode/ anode.
        Eg: Cu and Silver as electrodes: silver (higher molecular weight) --> lose more mass over time
- - - - Lined to surface area exposed to electrolyte
      - Linked to SA:Vol ratio
    - - Copper
      - Graphite
      - Titanium
      - Brass
      - Silver
      - Platinum
  - - - According to LeChanterlier's principle
  - - - String
      - Cotton
      - Filter paper
      - Fritted glass
- - - - Joule
      - Kilowatt-hour
      - E°cell: Cell potential
      - Vmax: the maximum velocity of the reaction
      - Faraday's constant:
        the amount of electric charge carried by one mole, or Avogadro's number, of electrons.
    - - Efficiency in performance
      - Cleanliness
      - Cost
- - - - Produce metal coating on a solid substrate
- - - - Wire, strips of two metals, electrolytes- ion solutions of the two ions, beakers, multimeters, and salt bridge are needed
      - Set up as follow:
      - Examples:
        Electrode: Zn and Cu
        Electrolyte: each of the metal nitrate
    - - Having a more reactive metal and less reactive metal
      - The more reactive one will replace the less reactive element from its compound
      - Expected observation includes change in colour
      - No precipitate formed
      - Metals react with the salt solution
  - - - to drive a thermodynamically unfavored redox reaction
      - oxidation occurs at the anode
      - reduction occurs at the cathode
      - Assemble an electrolytic cell to perform electroplating
        
        anode and cathode connected by a power source
      - Another example:
        
        Electrolytic cell:
        Copper anode
        A key for cathode