SPM Chemistry

Industrial Applications of Electrolysis – Electroplating

Industrial Applications of Electrolysis – Electroplating

  1. Electroplating is a process to coat an object with a thin protective layer of metal
  2. Electroplating is used to
    1. prevent corrosion
    2. improve the appearance of the objects
  3. In electroplating,
    1. the anode is the electroplating metal
    2. the cathode is the object to be electroplated
    3. the electrolyte must contain the ions of the plating meta

Example: Electroplate a Key with Copper

Electrolyte:
Copper(II) sulphate

CuSO4 —> Cu2+ + SO42-

Electrode:
Anode: Copper
Cathode: Object to be electroplated

Chemical Reaction
Anode:

Cu —> Cu2+ + 2e

In anode, the copper atoms from the electrode are ionised to form copper(II) ions.

Note: The anode is then made of the metal we wish to plate with (copper), and the electrolyte needs to be a solution of a salt of this metal (copper(II) sulphate).

Cathode

Cu2+ —> Cu + 2e

In cathode, the copper ions are discharged to form copper atom and then deposit on the surface of the key

Note: we need to make the cathode the object for plating

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