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Among the most important chemical reactions are oxidation reduction reactions. Redox reactions, as they are known, are energy-producing events in both industry and the human body. A redox reaction is defined by the transfer of one or more electrons from one substance to another. The species that loses electrons is referred to as oxidised, whereas the species that gains electrons is referred to as reduced. These terms are from the past, yet they are still used today. Oxidation and reduction take place at the same time.
To help us figure out which element gets oxidised and which is reduced in a chemical process, oxidation numbers are assigned to each element. An element gets oxidised when its oxidation number rises (becomes more positive) during a process. The oxidation number of an element, on the other hand, falls, indicating that the element is being reduced. Redox equations are balanced using changes in oxidation values as well. The goal is to maintain the total number of electrons lost in oxidation and the total number obtained in reduction equal. Obviously, understanding about oxidation numbers is a good place to start when studying oxidation-reduction reactions.
The oxidation states of atoms are changed in a redox (reduction–oxidation) reaction. The real or formal transfer of electrons between chemical species is defined by redox reactions, with one species (the reducing agent) suffering oxidation (losing electrons) and another species (the oxidising agent) undergoing reduction (gaining electrons). When an electron is withdrawn from a chemical species, it is said to be oxidised, but when an electron is added, it is said to be reduced.
“An oxidation reaction occurs when oxygen is given to a molecule or hydrogen is removed.”
Oxygen addition
Magnesium oxide is created when oxygen is added to it.
Hydrogen removal
Free iodine is obtained by removing hydrogen from hydroiodic acid.
“A reduction reaction occurs when a material loses oxygen or gains hydrogen.”
Redox Reactions in Terms of Electron Transfer Reactions
Electrons are transported from the metal atoms to the nonmetal atoms during a chemical reaction between a metal and a nonmetal. Zinc sulphide, for example, is created when zinc metal is combined with sulphur and heated. Each sulphur atom receives two valence electrons from zinc atoms.
The zinc is being oxidised because it is losing electrons throughout the reaction. As the sulphur gains electrons, it is reduced. A whole or partial transfer of electrons from one reactant to another is known as an oxidation-reduction process. The loss of electrons or the gain of oxygen is referred to as oxidation. The whole or partial acquisition of electrons, as well as the loss of oxygen, is referred to as reduction. Another name for an oxidation-reduction reaction is a redox reaction.
A half-reaction is a separate equation that can be used to represent each of these processes. In a redox reaction, a half-reaction is an equation that indicates either the oxidation or reduction process that occurs.
Oxidation: Zn→Zn2+ + 2e−
Reduction: S+2e−→S2−
It’s crucial to keep in mind that the two half-reactions take place at the same time. Ionic bonds are created as a result of the resultant ions being attracted to one another.
Zinc is oxidised by losing electrons in the mechanism described above. However, another chemical must be present to gain those electrons, which in this case is sulphur. To put it another way, the sulphur oxidises the zinc. The oxidising agent in this case is sulphur. Zinc is known as the reducing agent because it causes the sulphur to gain electrons and become reduced. A chemical that causes oxidation by receiving electrons is referred to as an oxidising agent. A chemical that promotes reduction by losing electrons is known as a reducing agent. The oxidising agent is the reduced material, while the reducing agent is the oxidised substance. How to assess a redox reaction is demonstrated in the problem below.
Conclusion
One or more electrons are lost or the element’s valency increases during oxidation.
Reduction is a chemical reaction in which an element gains one or more electrons or loses its valency.
The term “oxidising agent” refers to a substance that can gain one or more electrons, lowering its valency.
A reducing agent is a substance that can lose one or more electrons, resulting in a rise in valency.
One side of the redox reaction involves the loss of an electron or electrons (oxidation), while the other involves the gain of an electron or electrons (reduction) (reduction).
