Difference Between Electrolysis and Electroplating

Main Difference – Electrolysis vs Electroplating

Electrolysis is the use of an electric current for the progression of a certain chemical reaction. Electroplating is the use of an electric current for the plating of a certain metal on a different metal. Both these techniques are industrially used in the production of different equipment or compounds. The main difference between electrolysis and electroplating is that electrolysis is the use of electrical current to drive a non-spontaneous chemical reaction whereas electroplating is the use of electrical current to plate one metal on another metal.

Key Areas Covered

1. What is Electrolysis
      – Definition, Mechanism, Examples
2. What is Electroplating
     – Definition, Mechanism, Examples
3. What are the Similarities Between Electrolysis and Electroplating
      – Outline of Common Features
4. What is the Difference Between Electrolysis and Electroplating
      – Comparison of Key Differences

Key Terms: Electrochemical Cell, Electrochemistry, Electrolysis, Electrolytic Cell, ElectroplatingDifference Between Electrolysis and Electroplating - Comparison Summary

What is Electrolysis

Electrolysis is the process of using a direct electrical current to drive a non-spontaneous chemical reaction. Electrolysis is done using an electrolytic cell. It is a type of electrochemical cell. The technique of electrolysis can be used to separate a compound into its ions or other components.

In electrolysis, an electric current is sent through a solution for the mobility of ions in that solution. An electrolytic cell is composed of two electrodes immersed in the same solution. This solution is called the electrolyte. The reaction that occurs the electrolyte should be induced electrically.

In the electrolytic cell, the anode is positively charged, and the oxidation reaction takes place on the anode; the cathode is negatively charged due to the reduction reaction on the cathode. Since the reaction is non-spontaneous, it will absorb energy from outside.

An essential factor in regulating the electrolytic cell is over potential. A higher voltage should be provided in order to proceed a non-spontaneous reaction. An inert electrode can also be used to provide the surface for the reaction that occurs.

There are many applications of electrolysis. One common application is the electrolysis of water. Here, water is used as the electrolyte. Then the reaction of the breakdown of water molecules into hydrogen and oxygen gases can be done.

Difference Between Electrolysis and Electroplating

Figure 1: Electrolysis of Water

Furthermore, some other applications of electrolysis are electrorefining, electrosynthesis, Mercury cell process, etc. All these processes use electrolysis for the breakdown of a complex compound into simpler compounds.

What is Electroplating

Electroplating is the process of plating one metal on another metal using electrical energy. Here also, an electrochemical cell, which is composed of two electrodes immersed in the same electrolyte, is used. The cathode should be the electrode that is going to be plated. The anode can be either the metal that has to be plated on the cathode or an inert electrode.

When an electrical current is given from outside, the electrons are passed from anode to cathode. Therefore, the cathode has electrons that can be given to the metal ions in the solution. When metal ions get electrons, these metal ions are reduced and become the metal atoms. These metal atoms are deposited on the surface of the cathode. This is what we call plating.

Key Difference - Electrolysis vs  Electroplating

Figure 2: Copper electroplating on a metal (Me). Here, copper sulfate is used as the electrolyte. The anode is a copper electrode. The cathode is the metal that is going to be plated.

We should be careful when choosing the electrolyte. If it contains other metal ions that can be deposited along with the desires metal ion, the plating cannot be done properly. The electrode that the metal is plated on should be clean and free of contaminants. Otherwise, the plating cannot be done evenly. The electroplating is mainly used for decorative purposes or to prevent corrosion.

Similarities Between Electrolysis and Electroplating

  • Electroplating is a type of electrolysis.
  • Both types use electrolytic cells.
  • Both types use the same electrolyte to immerse both electrodes.
  • In both techniques, the oxidation occurs on the anode whereas the reduction occurs on the cathode.
  • Both techniques require a direct current (not alternating current).

Difference Between Electrolysis and Electroplating

Definition

Electrolysis: Electrolysis is the process of using a direct electrical current to drive a non-spontaneous chemical reaction.

Electroplating: Electroplating is the process of plating one metal on another metal using electrical energy.

Mechanism

Electrolysis: In electrolysis, a non-spontaneous reaction is driven with the help of an electric current.

Electroplating: In electroplating, a surface is coated with metal ions.

Applications

Electrolysis: Electrolysis is used for electrorefining, Electrosynthesis, Mercury cell process, etc.

Electroplating: Electroplating is used for decorative purposes or to prevent a metal from corrosion.

Conclusion

Electroplating can be described as an application of electrolysis since electrolysis is the basic technique used for electroplating. Therefore, there are many similarities between them. But they are different from each other according to their application. The basic difference between electrolysis and electroplating is that electrolysis is the use of electrical current to drive a non-spontaneous chemical reaction whereas electroplating is the use of electrical current to plate one metal on another metal.

References:

1.“Electrolysis.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 5 Mar. 2014, Available here. Accessed 20 Sept. 2017.
2. “Electrolysis.” Chemistry LibreTexts, Libretexts, 21 July 2016, Available here. Accessed 20 Sept. 2017.

Image Courtesy:

1. “Electrolysis” By © Nevit Dilmen (CC BY-SA 3.0) via Commons Wikimedia
2. “Copper electroplating” By GalvanostegiePrinzipskizzeTy.svg: Torsten Henningderivative work: Wizard191 (talk) – GalvanostegiePrinzipskizzeTy.svg (Public Domain) via Commons Wikimedia

About the Author: Madhusha

Madhusha is a BSc (Hons) graduate in the field of Biological Sciences and is currently pursuing for her Masters in Industrial and Environmental Chemistry. Her interest areas for writing and research include Biochemistry and Environmental Chemistry.

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