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Redox processes that transfer electrons between reactants to generate products utilise the phrases oxidising and reducing agents to describe the reactants.
This article explains what an oxidising or reducing agent is, how to identify oxidising and reducing agents in a chemical reaction, and the significance of this concept in real-life situations.
The reaction between hydrogen and fluorine gas to generate hydrofluoric acid is an example of a reaction:
2 HF⇔ H2 + F2
Hydrogen is oxidised while fluorine is reduced in this process. If the reaction is expressed in terms of two half-reactions, it may be easier to understand.
Oxidation in the Presence of Oxygen: A Historical Definition
When oxygen was added to a chemical, it was referred to as oxidation. Because oxygen gas (O2) was the first known oxidising agent, this was the case. While adding oxygen to a substance usually results in electron loss and an increase in oxidation state, the definition of oxidation has been broadened to cover different sorts of chemical processes.
When iron reacts with oxygen to generate iron oxide or rust, this is a classic illustration of the classical concept of oxidation. Rust is said to have formed from the iron. The chemical reaction is as follows:
2Fe2O3 = 2 Fe + 3O2.
The iron metal is oxidised, resulting in the formation of iron oxide, sometimes known as rust.
Oxidation reactions can take several forms, including electrochemical reactions. When a copper wire is immersed in a solution containing silver ions, electrons from the copper metal are transferred to the silver ions. The metal copper has oxidised. Copper ions are released into the solution as silver metal whiskers grow on the copper wire.
The reaction between magnesium metal and oxygen to generate magnesium oxide is another example of oxidation where one element interacts with oxygen.
Reduction and Oxidation Occur at the Same Time (Redox Reactions)
When the electron was discovered and chemical reactions could be explained, scientists realised that oxidation and reduction happen simultaneously, with one species losing electrons (oxidised) and the other gaining electrons (reduced) (reduced). A redox reaction, which stands for reduction-oxidation, is a type of chemical reaction that involves oxidation and reduction.
The metal atom losing electrons to form the cation (being oxidised) and the oxygen molecule receiving electrons to generate oxygen anions might then be interpreted as the metal atom losing electrons to form the cation (being oxidised).
Hydrogen-Involved Oxidation: A Historical Definition
According to the contemporary definition of the term, oxidation that involves oxygen is still oxidation. However, you may come across another ancient definition including hydrogen in organic chemistry textbooks. This term is the polar opposite of the oxygen definition, which could lead to misunderstanding. Even so, it’s a good idea to be aware. The loss of hydrogen is defined as oxidation, whereas the gain of hydrogen is defined as reduction.
Because it loses hydrogen, ethanol is termed oxidised. By reversing the equation, ethanal can be converted to ethanol by adding hydrogen to it.
Remembering Oxidation and Reduction with the OIL RIG
So, keep in mind that the contemporary definitions of oxidation and reduction are both concerned with electrons (not oxygen or hydrogen). OIL RIG is a useful tool for remembering which species are oxidised and which are reduced. Oxidation Is Loss, Reduction Is Gain is the acronym for OIL RIG.
Reducing and oxidising agents
In a chemical process, an oxidising agent, also known as an oxidant, obtains electrons and is reduced.
The oxidising agent, also known as the electron acceptor, is generally in one of its higher oxidation states since it will receive electrons and be reduced.
Halogens, potassium nitrate, and nitric acid are examples of oxidising agents.
In a chemical process, a reducing agent, also known as a reductant, loses electrons and is oxidised.
When a reducing substance is in one of its lower oxidation states, it is referred to as an electron donor.
Because it loses electrons in the redox reaction, a reducing agent becomes oxidised. Earth metals, formic acid, and sulfite compounds are examples of reducing agents.
A redox pair is a pair of oxidising and reducing agents that are involved in a certain process.
A redox pair is made up of a reducing species and its oxidising counterpart, for example, Fe2+ / Fe3+.
Although the generation of oxides from oxygen molecules is generally connected with oxidation events, other chemical entities can perform the same role.
Conclusion
Redox processes that transfer electrons between reactants to generate products utilise the phrases oxidising and reducing agents to describe the reactants.
This article explains what an oxidising or reducing agent is, how to identify oxidising and reducing agents in a chemical reaction, and the significance of this concept in real-life situations.
The reaction between hydrogen and fluorine gas to generate hydrofluoric acid is an example of a reaction:
2 HF⇔ H2 + F2.
Hydrogen is oxidised while fluorine is reduced in this process. If the reaction is expressed in terms of two half-reactions, it may be easier to understand.
