An oxidation–reduction process, often known as a redox reaction, is a reaction in which electrons are transferred between chemical species (the atoms, ions, or molecules involved in the reaction).
The oxidation number increases during oxidation, while the oxidation number decreases during reduction. The loss or gain of electrons is usually connected with a change in oxidation number, but some redox reactions (such as covalent bonding) do not entail electron transfer.
Redox reactions can be identified using oxidation numbers, which are assigned to atoms in molecules based on the assumption that all links between them are ionic.
Oxidation Numbers
How can we determine if a particular reaction is a redox reaction? In some cases, it is possible to tell by visual inspection. For example, we could have determined that the rusting of iron is a redox process by simply noting that it involves the formation of ions
(Fe3+ and O 2- ) from free elements (Fe and O2 ) In other cases, however, it is not as obvious, particularly when the reaction in question involves only nonmetal substances.
To help identify these less obvious redox reactions, chemists have developed the concept of oxidation numbers, which provides a way to track electrons before and after a reaction. An atom’s oxidation number (or oxidation state) is the imaginary charge that the atom would have if all of the bonds to the atom were completely ionic.Oxidation numbers can be assigned to the atoms in a reaction using the following guidelines:
1.An atom of a free element has an oxidation number of 0. For example, each Cl atom in Cl2 has an oxidation number of 0. The same is true for each H atom in H2 each S atom in S8, and so on.
2.When combined with other elements, alkali metals (Group1A) always have an oxidation number of +1, while alkaline earth metals (Group 2A) always have an oxidation number of +2.
3.Fluorine has an oxidation number of -1 in all compounds.
4. Hydrogen has an oxidation number of +1 in most compounds. The major exception is when hydrogen is combined with metals, as in NaH or LiAlH4. In these cases, the oxidation number of hydrogen is −1.
Examples of Oxidation
The typical example of oxidation is rust. Brown iron (III) oxide is formed when iron metal is oxidised. Zinc metal oxidises to the zinc (II) ion when it replaces silver or copper in a solution. An oxidation reaction is when something is burned in oxygen, such as sugar or magnesium.
Bleaching something, such as hair, blue trousers, or luminous tonic water, is an oxidation-reduction reaction in which the oxidizer is sodium hypochlorite.
Rancidity : When fried foods are exposed to air for an extended period of time, they develop a nasty odour and a bad taste.
Oxidation State
“The act of oxidising or being oxidised,” “the gain of oxygen, such as when an element mixes with oxygen to produce its oxide, such as rusting,” and, finally, “the loss of electrons during a reaction, resulting in an atom increasing its oxidation state.” For chemistry, the last definition is the one to remember.
When an atom loses one or more electrons during a chemical reaction, the oxidation number of the atom increases. This is due to the atom losing its electron’s negative charge, which is equivalent to receiving a positive charge, therefore increasing the oxidation number.
We say something has been oxidised when bleach or hydrogen peroxide makes it white. The bleach’s hypochlorite ion, or peroxide ion, obtains electrons, while the substance that turns white (by default, the reducing agent) loses them.
Alkene Oxidation Reactions
The C=C double bond in alkenes is oxidised in a variety of processes. Checking the number of C–O or C–H bonds in organic compounds is a common approach to determine if oxidation or reduction has occurred.
The amount of C–O bonds increases in an oxidation reaction, while the number of C–H bonds decreases. A reduction process, on the other hand, increases the amount of C–H bonds or decreases the number of C–O bonds.
Redox Reactions
Redox reactions, also known as oxidation–reduction processes, are reactions in which electrons are transferred from one species to another.
An oxidised species is one that loses electrons, while a reduced species is one that obtains electrons.
Redox reactions can be identified using oxidation numbers, which are assigned to atoms in molecules based on the assumption that all links between them are ionic.
During a reaction, an increase in the oxidation number refers to oxidation, whereas a drop relates to reduction.
Conclusion
An oxidation–reduction process, often known as a redox reaction, is a reaction in which electrons are transferred between chemical species (the atoms, ions, or molecules involved in the reaction).
Redox reactions may be found all around us: fuel combustion, metal corrosion, and even photosynthesis and cellular respiration entail oxidation and reduction.
Redox reactions, also known as oxidation–reduction processes, are reactions in which electrons are transferred from one species to another. An oxidised species is one that loses electrons, while a reduced species is one that obtains electrons.
Redox reactions can be identified using oxidation numbers, which are assigned to atoms in molecules based on the assumption that all links between them are ionic.