chemistry - chemical and fuel cells

Cards (9)

  • Cell
    Composed of two electrodes dipped in an electrolyte solution. It produces electricity from a chemical reaction.
  • Battery
    Consists of two or more cells connected in series
  • Voltage obtained from a cell
    Determined by the identities of metals used as electrodes and the identity and concentration of an electrolyte
  • Advantages and disadvantages of using cells and batteries
    • Advantages: more or less cheap, some are rechargeable, a convenient source of electrical energy
    • Disadvantages: harmful chemicals
  • Rechargeable cells
    Chemical reactions are reversed when an external current is supplied
  • Non-rechargeable cells
    Reactants are used up, cannot be recharged
  • Fuel cell
    Supplied by fuel and oxygen to oxidise the fuel to generate electricity
  • Overall reaction in a hydrogen fuel cell
    1. Cathode: 2 H2 → 4 H+ + 4 e−
    2. Anode: O2 + 4 H+ + 4 e−→ 2 H2O
    3. Overall: 2 H2 + O2 → 2 H2O
  • Advantages and disadvantages of hydrogen fuel cells
    • Advantages: no pollutants, no recharging
    • Disadvantages: flammable, H2 difficult to store, fossil fuel production, toxic chemicals, expensive production of H2 by electrolysis