All About IUPAC Definition Of Oxidation

The complete removal of one or more electrons from a molecular entity is called oxidation. For example, all atoms in the simple sulphur-containing compounds specified in the IUPAC definition may easily assign the correct oxidation states.

Because H atoms (O atoms) have a lower (higher) electronegativity than sulphur (and H) atoms and form one (two) covalent bonds, they inevitably arrive at oxidation states of +I (II).

The oxidation state (OS) of an atom in a molecule is a basic numerical feature that facilitates the systematic descriptive chemistry of the elements, gauges trends in attributes, and tracks significant chemistry changes in reactions.

Due to the lack of a thorough definition, OS has been defined so far through methods for its computation or with hypothesised values. This paper defines OS using the ionic approximation of chemical bonding.

IUPAC Definition

IUPAC published in its technical report “Towards a comprehensive definition of Oxidation state” in 2014 as the charge on an atom after an ionic approximation of its heteronuclear bonds.

The terms oxidation number and oxidation number are almost identical.

The essential premise is that the ionic charge is “the oxidation state of an atom following ionic approximation of its bonds,” with ionic approximation implying that all bonds are ionic.

For the ionic approximation, many criteria were considered:

Extrapolation of the bond’s polarity from the electronegativity difference, the dipole moment, and quantum chemical charge calculations.

Electrons are assigned based on the atom’s contribution to the bonding.

In an LCAO–MO model, the electron’s loyalty is represented by a molecular orbital (MO).

The electrons in a bond between two distinct elements are assigned to the bond’s principal atomic contributor/higher electronegativity; the electrons are divided evenly in a union between two atoms of different elements.

Since most electronegativity scales are dependent on the atom’s bonding state, assigning the oxidation state is a rather circular argument.

Some scales, for example, may produce strange oxidation states, such as -6 for platinum in PtH42- for the Pauling and Mulliken scales.

How To Calculate the Oxidation Number Of An Element In A Compound?

Explanation:

• A free element’s oxidation number is always 0.
• The charge of a monatomic ion is equal to its oxidation number.
• When coupled with fewer electronegative elements, the oxidation number of H is -1.
• The oxidation number of O in compounds is normally -2, while in peroxides, it is -1.
• A Group 1 element in a compound has an oxidation number of +1.
• A Group 2 element in a compound has an oxidation number of +2.
• A Group 17 element in a binary compound has an oxidation number of -1.
• The total oxidation number of all atoms in a neutral substance is 0.
• The sum of the oxidation numbers in a polyatomic ion equals the ion’s charge.

Conclusion

Attempting to study both definitions of oxidation and reduction in the grounds of electron transport and the definitions of oxidising and reducing agents in the same terms might lead to confusion.

The following thinking pattern may be of assistance:

• An oxidising agent oxidises something else.
• The loss of electrons is referred to as oxidation (OIL RIG).
• As a result, an oxidising agent steals electrons from the other material.
• As a result, an oxidising agent must acquire electrons.