Oxidation

Introduction

The loss of electrons by a molecule, atom, or ion during a reaction is oxidation. Whenever the oxidation state of a molecule, atom, and ion is enhanced, it is called oxidation. The opposite process reduces when an atom, molecule, and ion gains electrons or its oxidation level drops.

Oxidation is the loss of electrons at its most fundamental level. Whenever an atom or a complex loses one or even more electrons, this happens. Certain elements are more prone to losing electrons than others. These elements are said to oxidize quickly. Metals such as sodium, magnesium, or iron, in general, are easily oxidized.

Elements that are more reluctant to release electrons are more difficult to oxidize; they tightly cling to their electrons. Nitrogen, oxygen, and chlorine are nonmetals that are difficult to oxidize.

The Process of Oxidation

The properties of an atom and compound change as it is oxidized. Whenever an iron object, for example, gets oxidized, it is altered because electrons are lost. Oxidized iron is a brittle, reddish powder, whereas unoxidized iron is a strong, structurally sound metal.

When iron is oxidized, it takes on a charge. It now has a positive charge of three due to the loss of three electrons. The number three and just a positive sign (+3) printed as a superscript to the right of the Iron (Fe) symbol denote this positive three charge.

Iron is rapidly oxidized; it’s crucial to keep it out of contact with oxygen plus moisture. As long as oxygen is there, iron would continue to lose electrons.

Oxidation and Reduction occur together (redox reaction)

When the electron was discovered and chemical processes could be described, scientists learned that oxidation and reduction occur simultaneously, with one species losing electrons (oxidized) and the other receiving electrons (reduced). A redox reaction is reduction-oxidation, which is a type of chemical reaction that involves oxidation and reduction.

 Zn (s) + Cu+2 (aq) → Cu (s)  + Zn+2 (aq) …… (Redox Reaction)

In above reaction Zn metal is oxidized to Zn+2 ion by losing 2e– and Cu+2 ions are reduced by gaining 2e– to Cu metal.

The oxidation of metal by oxygen gas is explained by the metal atom losing electrons to produce the cation (being oxidized) and the oxygen molecule acquiring electrons to generate oxygen anions. 

Oxidizing Agents 

Oxidizing agents are the substances that are the primary cause of the oxidation of any substance. In other words, the oxidizing agent, often known as an oxidant or oxidizer, is a substance that may oxidize other compounds or receive their electrons. Oxygen, hydrogen peroxide, and halogens are common oxidizing agents.

An oxidizing agent is a chemical compound that conducts a chemical reaction in which one or more electrons are gained. It is, in that sense, a component of an oxidation-reduction (redox) process. In the second meaning, an oxidizing agent is a chemical entity that transfers electronegative atoms, often oxygen, to a substrate. Atom-transfer reactions are involved in combustion, numerous explosives, and organic redox reactions.

The oxidizing agent is referred to as an electron acceptor, whereas the reducing agent is referred to as an electron donor. The ferrocenium ion is a well-known oxidizing agent.

Examples of Oxidation

1. Let us take the case of a burnt fruit you’d rather not consume. The soft insides of fruit get oxidized when exposed to oxygen in the air, causing them to break down and turn brown. Oxygen takes electrons between atoms and molecules in a process comparable to rusting. The unoxidized form of these chemicals differs from the oxidized version, which is undesirable to eat. 

 2 Zn (s)    +     O2  (g)     → 2 ZnO (s) …… (Oxidation Reaction)

In above reaction Zn metal is oxidized to ZnO

2. Many superfoods are marketed as containing antioxidants, a food tangent. An antioxidant is a substance that prevents other substances from oxidizing. Consuming antioxidants should, in theory, help our bodies in combating the negative effects of oxidation, maintaining our cells, including enzymes happy and healthy. To put it another way, consuming blueberries, blackberries, walnuts, plus cranberries would keep our insides from turning brown.

Oxidation-state Change

Complete explanations of oxidation and reduction are now possible because of a new molecular structure theory. Each atom has a positive nucleus surrounded by negative electrons that define the bonding properties of each element. While forming chemical bonds, atoms contribute, gain, or swap electrons. This permits each atom to be given an oxidation number that determines how many electrons could form bonds with other atoms. The unique atoms in a molecule and its stated bonding ability define the bonding trend within the molecule, so each atom must be regarded in a particular oxidation state characterized by an oxidation number.

Redox processes are defined as reactions followed by oxidation-state changes: an increase in atom oxidation corresponds to oxidation; a decrease in oxidation correlates with decreasing. Redox processes are reactions followed by oxidation state changes, with an increase in the oxidation number of an element corresponding to oxidation and just a drop in the oxidation number corresponding to reduction. Fe+3, or iron in an oxidation state of +3, is an example of an oxidation state of an element.

Conclusion

An oxidation-reduction process is a chemical reaction in which electrons are transferred between two substances. The loss of electrons in oxidation is called oxidation, while the gain of electrons is called reduction. The reducing agent loses electrons and is oxidized, while the oxidizing agent receives electrons and therefore is reduced. Because the reduction of one molecule causes the oxidation of the other, oxidation and reduction would always occur simultaneously. The reducing agent would shift to a more positive or neutral state, whereas the oxidizing agent would shift to a more negative state (less positive). Under specific guidelines, oxidation numbers are assigned, which helps in determining which molecules were oxidized and reduced during the process.