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It is crucial to understand whether an atom loses or gains electrons when interacting with other atoms to form compounds. This is done by looking at an atom’s oxidation number.
An oxidation number is a number assigned to an atom of a material. The oxidation number, positive, negative, or zero, reflects whether electrons are lost or acquired.
In other terms, an oxidation number is a number that helps track electrons within an atom.
Number of Oxidations
In this case, calcium has an oxidation number of +2, and oxygen has an oxidation number of -2. If the oxidation number is positive, the atom is losing electrons; if it is negative, the atom is gaining electrons. If it is 0, the atom does not gain or lose electrons. Calcium has a +2 charge, indicating that it has lost two electrons. Because oxygen has a -2 charge, it has gained two electrons. When an atom loses electrons, its oxidation number increases, and we can say that the atom oxidises. When an atom gains electrons, its oxidation number decreases, implying that the atom is reduced. Remember the phrase OIL RIG: Oxidation Is Loss (of electrons); Reduction Is Gain (of electrons).
Oxidation with oxygen
As an older form of oxidation, oxygen has been added to a molecule. This was because oxygen gas was the first understood oxidising agent (O2).
Although oxygen is given to a substance to meet the criteria of electron loss and increase in oxidation, the oxidation idea has been broadened to include additional chemical processes.
A typical example of an oxidation reaction is the old oxidation notion of iron reacting with oxygen to form iron oxide, where rust is formed as the iron oxidises.
The resulting chemical reaction is: 2Fe + O2 → Fe2O3
Rust is created as a result of the oxidation of iron oxide.
Hydrogen-based oxidation
The contemporary definition of oxidation is oxygen-based oxidation. There is another way to describe hydrogen that can be employed in organic chemistry. This is the inverse of the idea of oxygen, which might lead to confusion. It’s still a good idea to be aware of it.
According to the description, oxidation results in hydrogen loss, whereas reduction results in hydrogen gain.
When ethanol is generated by oxidising ethanol, this is an example of this.
CH3CH2OH → CH3CHO
It is well known that ethanol is oxidised by hydrogen loss. Ethanol can be reduced by reversing the equation and adding hydrogen to it.
The Oxidation Method
The oxidation and reduction processes occur in tandem and cannot be carried out independently. Individual oxidation and reduction reactions are considered half-reactions, and two half-reactions combine to form a complete reaction. The electrons gained or lost are utilised explicitly to balance the half-reaction with the electric charge. The electrons tend to cancel out when these half-reactions are combined to form a net chemical equation.
Agents that oxidise and reduce
During the redox process, the reducing agent transfers electrons to the oxidant. Thus, electrons are lost and oxidised by the reduction agent in the reaction, whereas it is reduced by acquiring electrons by the oxidising agent.
Oxidisers
Oxidisers are compounds that can lose electrons from another substance and are referred to as oxidising agents. In other words, the oxidising agent reduces itself by removing electrons from another material.
Because it receives an electron, the oxidising agent is also known as an electron acceptor. Oxidising agents include high oxidation state compounds such as H2O2, MnO4–, and strongly electronegative elements such as O2, F2.
Conclusion
An atom’s oxidation state equals the total amount of electrons removed from an element (creating a positive oxidation state) or added to an element (generating a negative oxidation state) to bring it to its current condition. Understanding the concept of oxidation states begins with recognising this simple pattern.Without electron-half-equations, the change in the oxidation state of an element during a reaction determines whether it has been oxidised or reduced.
