What is the Difference Between Oxidation Number and Charge?

The main difference between oxidation number and charge lies in the context of the molecule or atom being considered:

• Oxidation Number: This is a concept related to covalently bonded molecules, where an atom is assigned a "fictional charge" as if the molecule was bonded ionically. Oxidation numbers help in understanding the electron distribution within a molecule and are used to track changes in redox reactions.
• Charge: This refers to the actual net charge of an atom or molecule, which can be positive, negative, or neutral. Charges can only exist within ionically-bonded compounds.

In summary:

1. Oxidation numbers are assigned to atoms in covalently bonded molecules to understand the electron distribution and are used in redox reactions.
2. Charges describe the actual net charge of an atom or molecule, which can only exist within ionically-bonded compounds.

Keep in mind that charges are always written with the correct numerical value and sign, e.g., Al^(3+), while oxidation numbers are usually written with the sign only, e.g., Al^(+3).

Comparative Table: Oxidation Number vs Charge

The following table highlights the differences between oxidation numbers and charges:

In summary, oxidation numbers describe the number of electrons lost or gained by atoms in a molecule, while charges describe the net charge on an ion or molecule. Oxidation numbers are assigned to atoms in both covalent and ionic bonds, whereas charges are assigned to ions and molecules. Oxidation numbers can be positive, negative, or zero, while charges can be positive or negative.