Electroplating, Silver Plating, Copper Plating, Difference between Electrolysis and Electroplating (For CBSE, ICSE, IAS, NET, NRA 2022)

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How Does Electroplating Work?

Electroplating Work
  • Electroplating is the coating of an object with a metal.
  • It is done by immersing the object and a bar of the metal in a solution containing the metal ions.
  • It is the process of plating one metal onto another by hydrolysis, most commonly for decorative purposes or to prevent corrosion of a metal. Electric current is then applied; the positive goes to the metal and the negative goes to the object.
  • This is done by dipping two terminals called electrodes into the electrolyte and connecting them into a circuit with a battery or other power supply.
  • The metal bar dissolves in the solution and plates out on the object, forming a thin but durable coating of metal. It is often used to gold-plate objects for decoration or to stop corrosion.
  • The process itself involves creating an electrolytic cell: a device that uses electricity to deliver molecules to a particular location. Normally the metal becomes fragile and is only used for display.
  • It is known as electrode position because the process involves depositing a thin layer of metal onto the surface of a work piece, which is referred to as the substrate.
  • The Purposes of Electroplating:
    • Appearance
    • Protection
    • Special surface properties
    • Engineering or mechanical properties, etc.

Silver Plating

  • The object that is to be plated is connected to the negative terminal of the power supply.
  • A piece of silver is connected to the positive terminal. The electrolyte is a silver nitrate solution.
  • This process can also be used to purify silver.
  • We can take an impure block at the positive terminal and a strip of pure silver to the negative.
  • The pure silver is deposited via electrolysis at the negative terminal leaving behind the impurities.

Copper Plating

  • The object that is to be plated is connected to the negative terminal of the power supply.
  • A piece of copper is connected to the positive terminal.
  • The electrolyte is copper Sulphate solution.
  • Like with silver plating, copper deposition can be used to purify copper. In this case, both the electrodes are made from copper.
  • As the impure positive electrode gradually disappears leaving the impurities behind the negative electrode gradually gets coated with pure copper.

Difference between Electrolysis and Electroplating

Difference between Electrolysis and Electroplating
Electrolysis refers to the breaking apart of a molecule by the means of electrochemical reaction.Electroplating refers to the passage of current through the solution with metal such that it gets deposited on one of the electrodes.
Electrolysis is good for carrying out the non-spontaneous chemical reactions.Electroplating is good when metallic ions need to be coated on other metal.
Electrolysis is used for the extraction of metals from its ores.Electroplating is used for coating metals on pure metals.
Finds applications in electrosynthesis, mercury cell process, and electrorefining.Finds application in preventing metals from corrosion.

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