Oxidation is not always associated with the presence of oxygen! When oxygen produced electron loss in a reaction, the word was first employed. The contemporary definition encompasses a broader range of topics.
During a process, a molecule, atom, or ion loses electrons, which is known as oxidation.
When a molecule’s, atom’s, or ion’s oxidation state is increased, it is called oxidation. When electrons are gained or the oxidation status of an atom, molecule, or ion lowers, the process is known as reduction.
The reaction of hydrogen with fluorine gas to produce hydrofluoric acid is an example of a reaction:
H2+ F2 → 2 HF
This process involves the oxidation of hydrogen and the reduction of fluorine. When expressed in terms of two half-reactions, the reaction may be more easily comprehended.
H2→ 2 H+ + 2 e–
F2 + 2 e–→ 2 F–
Oxidation Involving Hydrogen
According to the contemporary understanding of the term, any oxidation that involves oxygen is still considered oxidation. However, in organic chemistry textbooks, there is another old concept that involves hydrogen. This term is the polar opposite of the oxygen definition, which could lead to some misunderstanding. Nonetheless, it is beneficial to be alert. The loss of hydrogen is oxidation, while the gain of hydrogen is reduction, according to this definition.
When ethanol is converted to ethanal, for example, according to this definition:
CH3CH2OH → CH3CHO
Because ethanol loses hydrogen, it’s considered oxidised. Ethanal can be decreased by adding hydrogen to generate ethanol by reversing the equation.
Transferring hydrogen atoms
Hydrogen atoms are moved from hydrazine, a nitrogen-and-hydrogen molecule, to oxygen in the following reaction:
N2H4+ O2→ N2+ 2H2O
Hydrogen is lost when hydrazine is oxidised to molecular nitrogen, but oxygen is gained when it is reduced to water.
Hydrogen that can be used in organic chemistry
Hydrocarbons are chemical compounds that only contain carbon and hydrogen. Saturated hydrogen atoms are those that contain the most hydrogen atoms conceivable. Alkanes are the name given to saturated hydrocarbons.
Methane: CH4 is the most basic alkane. The Lewis structure of methane is created by mixing the four electrons in a neutral carbon atom’s valence shell with four hydrogen atoms to form a compound with a total of eight valence electrons shared by the carbon atom and the four hydrogen atoms.
Carbon is tetravalent in almost all of its compounds, and methane is an illustration of this rule. The shape around the carbon atom is tetrahedral, as seen in the picture below, to minimise the resistance between electron pairs in the four CH bonds.
Oxidation is the loss of hydrogen
None of these are unavoidable byproducts of the processes, but they are prevalent, particularly in biological reactions that are water-based and hence likely to incorporate hydrogen and oxygen.
The important thing to remember is that oxidation is defined as the loss of electrons, whereas reduction is defined as the gain of electrons in chemistry. Beginning to form a bond to a more electronegative atom is considered a loss (since that atom will hold the shared electrons more tightly) in reactions that do not involve a complete transfer of electrons (e.g. forming ions), while forming a bond to a less electronegative atom is considered a gain (because that atom will hold the shared electrons more loosely) (for the same reason but vice versa). Whenever another element (except fluorine, which is rather rare) establishes a connection with oxygen, it is oxidised. Because hydrogen is among the least electronegative elements that regularly forms covalent bonds (especially among the common elements involved in organic and biological chemistry), when another non-metallic element (e.g. carbon) forms a bond with hydrogen, it continues to hold the shared electrons more tightly and is considered to have gained an electron; thus, carbon in CH4 is considered more reduced than elemental carbon, and carbon in CO2 is considered more oxidised. (Oxidation states are -4, 0, and +4, respectively.)
Conclusion
Electrons are transferred away out of each hydrogen atom and toward the oxygen atom during this reaction. The hydrogen is oxidised when it loses some of its electrons. The hydrogen atoms in water have less electron density around them than they had in the H2 molecule, even though the loss isn’t complete enough to create ions. Because of a partial gain of electrons, oxygen is decreased. The electron density around the oxygen atom in water is higher than in the O2 molecule.
Another way to address this problem is to return to our earlier definitions of oxidation as the gain of oxygen or the loss of hydrogen, and reduction as the gain of hydrogen or the loss of oxygen. This simplifies the decision-making process for redox reactions. Because it incorporated oxygen to produce water, the hydrogen became oxidised. In contrast, because it added hydrogen to produce water, the oxygen is diminished.