Oxidizing and Reducing Agents

The complex and well-organized set of processes that make up life on the planet Earth. Plants and animals are both built to breathe oxygen. The process of photosynthesis provides us with the oxygen we require to live. When light strikes chlorophyll, a plant pigment, it sets off a complicated chain of reactions, many of which are redox processes involving electron transport. Water is transformed to oxygen gas in this chain of events, providing us with a source of oxygen.

A redox process that yields zinc sulphide is shown below:

Zn + S → ZnS 

The half-reactions can be written as:

Oxidation: Zn → Zn2+ +2e−

Reduction:S + 2e− → S2− 

Zinc is oxidised by losing electrons in the mechanism shown 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. The oxidising agent is a chemical that promotes oxidation by receiving electrons and hence decreases in oxidation state. The reducing agent is a chemical that reduces by losing electrons, resulting in a rise in oxidation state. The oxidising agent is the reduced material, while the reducing agent is the oxidised substance.

Oxidizing Agents

Oxidizing agents are atoms, ions, and compounds with a high affinity for electrons. The strongest common oxidising agent, for example, is elemental fluorine. Metals, quartz, asbestos, and even water all caught fire when exposed to F2. O2, O3, and Cl2, the elemental forms of the second and third most electronegative elements, respectively, are also effective oxidizers. Active metals with low electro-negativities and tiny ionisation energies, such as sodium, magnesium, aluminium, and zinc, are good reducing agents. Metal hydrides that technically contain the H− ion, such as NaH, CaH2, and LiAlH4 , are also effective reducers.

Some substances have the ability to serve as both oxidizers and reducers. When hydrogen gas reacts with metals, it functions as an oxidizer, but when it reacts with nonmetals, it acts as a reducer.

What a Reducing Agent Does

The next natural question is, of course, “What does a reducing agent do?” now that the concept of a reducing agent has been established. A reducing agent donates one or more of its own electrons to another chemical species, as the alternative name “electron donor” suggests. An atom, ion, or molecule could be this species. The reducing agent lowers the oxidation state of the receiving species by donating more electrons to it. The number of electrons involved in creating chemical bonds with another atom is referred to as the oxidation state. The electrons in these atoms can be obtained, lost, or exchanged. When an atom gains electrons, the charge on the atom is reduced. As a result, the reducing agent and the oxidising agent are both oxidised. This jargon can be perplexing to use. “OIL RIG” stands for “oxidation is loss, reduction is gain,” and is a useful mnemonic device to utilize here. Reducing agents lose electrons when they are oxidised. Each hydrogen (H) atom provides one electron to the fluorine (F) atoms, as seen in the illustration below. As a result, hydrogen serves as a reducing agent and is oxidised in the process.

Examples of Reducing Agent

Hydrogen is often used as an example of a reducing agent, as shown in the figure. Following is a list of other commonly used lowering agents:

Hydrogen is one of the most abundant elements on the (H)

CO (CO)

The metal (Fe)

Zinc is a mineral that occurs naturally in the (Zn)

Lithium is a chemical element that can be found in (Li)

It’s worth noting that the majority of the elements on this list are metals, such as iron, zinc, and lithium. Metals, particularly the alkaline earth metals, are frequently used as reducing agents.

Conclusion 

In a redox (oxidation-reduction) reaction, an oxidising agent is a chemical or element that accepts electrons from another species. An oxidant is a chemical molecule that easily transfers oxygen or other atoms to get an electron.

In a redox chemical reaction, a reducing agent (also known as a reductant, reducer, or electron donor) is an element or molecule that “donates” an electron to an electron recipient (called the oxidising agent, oxidant, oxidizer, or electron acceptor).

An oxidising agent is a chemical that promotes oxidation by receiving electrons, resulting in reduction. A reducing agent is a chemical that causes oxidation by losing electrons.