Electrolytic Cell

An electrolytic cell is an electrochemical cell in which electrical energy is used to carry out a chemical reaction in the cell. The chemical reaction happening inside an electrolytic cell is a redox reaction, which is spontaneous in nature. This whole process of carrying out chemical reactions with the help of an electric current is called electrolysis.

An electrolytic cell is an electrochemical device that uses electrical energy to start a chemical reaction. The cell consists of two electrodes (anode and cathode) immersed in an electrolyte solution. An external voltage is applied between the electrodes to drive a redox reaction at the electrode surfaces. This electric current causes the electrolyte to split into constituent ions, which are mobile in nature. The ion then starts moving towards the electrode in the manner that anions move to the anode and cations move to the cathode. This led to the deposition of elements of the electrodes. This whole process is called electrolysis. Hence, we can say that an electrolytic cell is a chemical cell that operates on the principle of electrolysis.

Components of Electrolytic Cell

The three main components of an electrolytic cell are:

• Anode: A positive electrode
• Cathode: A negative electrode
• Electrolyte: A liquid solution that conducts electricity

The electrolyte solution contains dissolved ions that move around the solution, allowing it to conduct electricity. The electrolyte can be either molten or in an aqueous solution.

Working of Electrolytic Cell

In an electrolytic cell, two electrodes are dipped into an electrolyte. When electric current is supplied to the electrolytic cell, the electrolyte breaks down into its constituent cations and anions. Now cations being positive in nature get attracted to negative diode which is cathode. The anion of the electrolyte being negative in nature get attracted to the anode which is a positive diode.

In this process, the anion at anode get lose its electron and get deposited as element. This process is called oxidation. Hence, in electrolytic cell oxidation occurs at anode.

The cation at cathode gains the electron and get deposited as metal. This process is called reduction. Hence, in electrolytic cell reduction occur at cathode.

This complete process is called electrolysis which is discussed below:

Reaction at Cathode: [Na⁺ + e^– → Na] × 2

Reaction at Anode: 2Cl^– → Cl₂ + 2e^–

Cell Reaction: 2NaCl → 2Na + Cl₂

Thus, molten sodium chloride when subjected to electric current in an electrolytic cell to generate metallic sodium and chlorine gas as the products.

Electrolytic Cell and Electrolysis

Electrolysis is a technique that uses an electric current to drive a chemical reaction that would otherwise not occur. Electrolytic cells are electrochemical cells that use an external source of electrical energy to force a chemical reaction.

The voltage needed for electrolysis to occur is called the decomposition potential. The solutions in electrolytic cells are usually either molten salt or aqueous.

Let's consider an example of electrolysis of brine solution. In brine solution, the electrolyte is NaCl solution. When electric current is passed, NaCl breaks down into Na⁺ and Cl^- ion. The sodium ion moves to cathode and get deposited as metal ion while Cl^- get moves to anode and get deposited as element. The reaction for the process is given below:

Reaction at Cathode: [Na⁺ + e^– → Na] × 2 where, E° = –2.71 V

Reaction at Anode: 2Cl^– → Cl₂ + 2e^– where, E° = –1.36 V

Cell Reaction: 2NaCl → 2Na + Cl₂ where, E° = –4.1 V

Electrolysis is used in many industrial processes, including:

• Refining metals.
• Producing inorganic and organic products.
• Producing chlorine and caustic soda.
• Refining aluminum.

Galvanic Cell Vs Electrolytic Cells

The difference between Galvanic Cell and Electrolytic Cell is tabulated below:

Applications of Electrolytic Cells

The applications of electrolytic cell is given below:

• Electrolytic Production of Chemicals: Electrolytic cells are used in the industrial production of various chemicals, including chlorine, sodium hydroxide, hydrogen peroxide, and aluminum. Electrochemical processes enable the conversion of raw materials into valuable chemical products through controlled electrochemical reactions.
  
• Electroplating: Electrolytic cells can be used in electroplating, which is the process of forming a protective layer of a specific metal on another metal.
  
• Electrolytic Capacitors: Electrolytic capacitors are electronic components that use an electrolyte as one of their conducting plates. They are widely used in electronic circuits for applications such as filtering, coupling, and energy storage due to their relatively high capacitance values and low cost.
  
• Electrorefining: Electrolytic cells are used in the electrorefining of metals, such as copper, zinc, and aluminum, to purify them. In the electrorefining process, impure metal is dissolved into an electrolyte solution, and pure metal is deposited on the cathode while impurities settle as anode mud or remain in the electrolyte. This process helps produce high-purity metals suitable for various industrial applications.
  
• Electrowinning: Electrolytic cells can be used in the electrowinning of metals like zinc, aluminum, copper, and lead.
  
• Electrolysis of Water: Electrolytic cells are employed in the electrolysis of water to produce hydrogen and oxygen gases. By passing an electric current through water, it undergoes decomposition into its constituent elements: hydrogen gas is evolved at the cathode, and oxygen gas is evolved at the anode. This process is used in various applications, including hydrogen fuel production, energy storage, and industrial processes.

Also Check:

• Types of Electric Cell
• Cathode and Anode
• Conductance of Electrolytic Solutions 
• Electrolytic Refining