Electrolysis

Michael Faraday coined the word electrolysis in the nineteenth century. It was one of the best methods for acquiring pure elements during the study of special chemical processes. Electrolysis is now frequently used in isolating or obtaining the purest form of elements from their natural source, including ores, making it an economically relevant process.

Define electrolysis

Electrolysis is a chemical reaction that occurs when a specific electric impulse is conducted through a material. When a material loses or gets an electron, it is referred to as a chemical change. An electrolytic cell is a device that consists of two electrodes that are placed at a distance and dipped in a solution containing oppositely charged ions. The material to be converted may form the electrode, make up the solution, or be dissolved in it. 

The negatively charged electrode (cathode) receives electric current (i.e., electrons); solution components go towards this electrode, mix with the electrons, and are converted (reduced). In this way, neutral elements or novel compounds can be produced. The solution’s components also move to the opposite electrode (anode), where they give up their electrons and are converted (oxidized) into neutral elements or new molecules. When the electrode is the substance that needs to be changed, the reaction is frequent, resulting in the electrode dissolving by losing electrons.

Electrolysis is widely employed in metallurgical processes, including metal extraction (electrowinning) and purification (electrorefining) from ores or compounds, as well as metal deposition from solution (electroplating). Electrolysis of sodium chloride in the molten form produces metallic sodium gas; electrolysis of an aqueous solution of sodium chloride produces sodium hydroxide and chlorine gas. The electrolysis of water produces hydrogen and oxygen.

The process of splitting up complex molecules into simpler and more basic substances is known as decomposition, and it requires the use of a catalyst that is able to force a chemical reaction. Before the discovery of catalysts like metal ions, temperature, pressure, and electromagnetic energy, certain reactions were simply impossible. This was particularly the case with non-spontaneous reactions where an element could not be separated from the other elements because it already existed in its purest form.

The electrolytic process

The addition and subtraction of electrons from the external circuit causes an exchange of ions and atoms in the electrolysis process. As the current is passed, the cations migrate to the specific cathode, receive electrons from a given cathode, and discharge into a neutral atom. A neutral atom is precipitated on the cathode if it is solid, and it moves upwards if it is gas. The cation always gets reduced at the cathode in the given reduction process.

At the same time, anions donate their additional electrons to the attached anode, where they are further oxidized to give neutral atoms. During the course of an electrical circuit, electrons produced by anions move across the circuit until they reach a cathode, where they complete the circuit. A random oxidation process at the given anode and a special reduction reaction on the cathode are involved in electrolysis.

For example, when the electric current is constantly being delivered through a solution of sodium chloride, the sodium ion present is drawn to the cathode, where it chooses an electrode and transforms into a neutral sodium atom.

When the chloride ion travels and reaches the opposite anode, it loses its electron and transforms into a chlorine atom, forming a chlorine molecule.

At Cathode : 

2 Na+ (aq) + 2 e–→ 2 Na (s) 

At Anode :

2 Cl– (aq) → Cl2 (g) + 2 e–

While the electrolysis process may be used directly to get the elemental conditions from compounds, it can also be manipulated and used indirectly involving metallurgy of alkali earth nonmetals and metals, metal purification, metal deposition, and compound preparation.

Electrolysis applications

As previously stated, electrolysis is the process of changing the ions of a liquid chemical into their reduced or oxidized form by sending an electric current through it. As a result, electrolysis has a wide range of uses in experimental and industrial goods. The following are a few of the most important uses:

1. Determination of equivalent weight of substances.

2. Metallurgy of alkali and alkaline earth metals.

3. Purification of metals.

4. Manufacture of pure gasses.

5. Manufacture of compounds like sodium hydroxide, sodium carbonate, potassium chlorate, etc.

6. Electroplating for corrosion resistance, ornaments, etc.

Conclusion

Electrolysis may be induced in electrolytic cells using a power source to provide the energy needed to drive electrons to flow in a non-spontaneous manner. Electrolysis is carried out in solutions containing enough ions to allow current to flow. When a solution includes one substance, such as the electrolysis of sodium chloride in molten form, determining what is oxidized and reduced is straightforward. 

Multispecies oxidation or reduction can occur in more intricate systems like electrolysis of aqueous sodium chloride, and average reduction potentials are used to identify which species is most probable (the half-reaction with the biggest, most positive, average reduction potential) to oxidize or reduce (the half-reaction with the smallest, least positive, average reduction potential). Overpotential can sometimes create unanticipated half-reactions. The discrepancy between the predicted half-reaction reduction potential and the actual voltage required is overpotential. The applied potential must be raised when this occurs, allowing a different reaction to occur in an electrolytic cell.