Definition of Oxidation
Oxidation is a chemical process that involves the loss of electrons by an atom, molecule, or ion. This loss of electrons results in an increase in the substance's oxidation state. While the term historically referred to reactions with oxygen, its modern definition is much broader, encompassing any process of electron removal.
Key Principles and Characteristics
When a substance undergoes oxidation, it acts as a reducing agent, meaning it causes another substance to be reduced while it itself is oxidized. Oxidation always occurs simultaneously with reduction in what are known as redox (reduction-oxidation) reactions. A common mnemonic to remember is LEO the lion says GER: Loss of Electrons is Oxidation, Gain of Electrons is Reduction.
A Practical Example of Oxidation
A well-known example is the rusting of iron. When iron (Fe) reacts with oxygen (O₂) and water, it forms iron oxide (rust). In this process, elemental iron, which has an oxidation state of 0, loses electrons to become iron ions (Fe³⁺), increasing its oxidation state. The specific half-reaction for the oxidation of iron is Fe → Fe³⁺ + 3e⁻.
Importance and Applications
Oxidation is fundamental to many natural and industrial processes. It is crucial for energy production within living organisms (e.g., cellular respiration), the corrosion of metals (like rusting), the burning of fuels (combustion), and various industrial chemical syntheses. Understanding oxidation is essential across diverse fields, from biochemistry and environmental science to materials science and engineering.