C5 - Cells and batteries

• Disadvantages of Cells

  1. Can only produce electricity for a certain period of time - eventually the reactants get used up and the reaction stops
  2. Only produces electricity if you use metals with different reactivities
• What is a cell? How can it be made?

  • A system containing chemicals which react to produce electricity
  • Can be made by connecting two different metals in contact with an electrolyte
• The greater the difference between the reactivity of the metals...

  the greater the potential difference produced by the cell
• What can also affect the potential difference?

  The electrolyte
• What is a battery?

  A battery contains two or more cells connected in series to provide a greater voltage
• Why are alkaline batteries non-rechargeable?

  It is not a reversible reaction
• Why do alkaline batteries stop working?

  The reactants in the batteries get used up
• Why can rechargeable batteries be recharged?

  The chemical reactions can be reversed when an electrical current is applied