Application of electrolysis.

Application of electrolysis

i. Purification of metals

In this method, blocks of the impure metal are used as the anode and sheets of extremely pure metal are used as the cathode. The process helps remove impurities from the metal.

Example: Copper is industrially purified by the electrolysis of aqueous copper(II) sulfate using copper electrodes, where the anode is impure and the cathode is pure. Similarly, zinc (Zn) is purified by electrolysis of zinc sulfate.

ii. Manufacture (extraction) of elements

Very reactive elements are extracted by electrolysis of their molten chlorides. Some examples of such elements include:

• Aluminum (Al)
• Magnesium (Mg)
• Sodium (Na)
• Potassium (K)

Further details on the extraction of these metals can be found in the topic of metal extraction.

iii. Electroplating

Electroplating is the process of covering a corroding material (usually metals) with a layer of a more unreactive metal using electrolysis. This not only prevents corrosion but also improves the appearance of the material.

In electroplating, the article to be plated is made the cathode, and the anode is made of the plating material.