Electrolysis, Definition, Electrolysis Process, Implementation of Electrolysis (For CBSE, ICSE, IAS, NET, NRA 2022)

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What is Electrolysis?

  • Electrolysis is a promising option for hydrogen production from renewable resources.
  • It is the process of using electricity to split water into hydrogen and oxygen. This reaction takes place in a unit called an electrolyzer.
  • Electrolyzes can range in size from small, appliance-size equipment that is well-suited for small-scale distributed hydrogen production to large-scale, central production facilities that could be tied directly to renewable or other non-greenhouse-gas-emitting forms of electricity production.


β€œThe process by which ionic substances are decomposed into simpler substances when an electric current is passed through them”

Electrolysis Process

Electrolysis Process
  • The fundamental process of electrolysis is the interchanging of ions and atoms by the addition or removal of electrons from the external circuit.
  • Ionic compounds contain charged particles called ions.
  • As an example, Sodium Chloride contains positively charged Sodium ions and negatively charged Chlorine ions.
  • … At Cathode
  • … At Anode
  • The ions must be free to move in order to start the electrolysis process. When an ionic substance is dissolved in water or melted then the ions are free to move.
  • During this process, positively charged ions move to the negative electrode and negatively charged ions move to the positive electrode.
  • Then positively charged ions receive electrons and negatively charged ions lose electrons.
  • Both the products of the dissociation get collected at the electrodes.
  • For instance, if electricity is passed through molten sodium chloride, the sodium chloride is broken into sodium and chlorine and they collect at their respective electrodes. The metals get precipitated and the gases escape. This ability to break down substance with a current is used in many ways.
  • It is widely used for Electroplating.

Implementation of Electrolysis

  • Before times aluminum was almost as precious as silver. Its extraction was not known and pure aluminium was extremely hard to come by.
  • The application of electrolysis turned aluminium from a precious metal to one of the most largely used metals by humans.
  • It is extracted from its ore by the process of electrolytic decomposition and deposition.

Electrolysis of Water

  • In pure water at the negatively charged cathode, a reduction reaction takes place, with electrons (e βˆ’) from the cathode being given to hydrogen cations to form hydrogen gas. The half reaction, balanced with acid, is:
    • Reduction at cathode:
  • At the positively charged anode, an oxidation reaction occurs, generating oxygen gas and giving electrons to the anode to complete the circuit:
    • Oxidation at anode:
  • The same half-reactions can also be balanced with the base as listed below. Not all half-reactions must be balanced with acid or base.
  • Electrolysis is done for coating one metal on another.
  • The industrial use includes various metals such as aluminium, magnesium, chlorine, and fluorine etc.

What is Electroplating?

Electroplating is a process that uses an electric current to reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode.

  • Electroplating is a process that uses electric current to reduce dissolved metal ions by the use of electrolysis, to obtain the dissolved metal ions at the other electrode, mostly in the form of a uniform coating.
  • It is the process of plating one metal onto another by hydrolysis, most commonly for decorative purposes or to prevent corrosion of metals.
  • There are also specific types of electroplating such as copper plating, silver plating, and gold plating. It allows the manufacturers to make the product with economical materials and then coat the metals to add properties such as rust proofing, improving its appearance and improving its strength.

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