What is the Difference Between Oxidation State and Oxidation Number?

🆚 Go to Comparative Table 🆚

The difference between oxidation state and oxidation number lies in their definitions and applications. Here are the key distinctions between the two concepts:

  • Oxidation State:
  1. Refers to the degree of oxidation of an atom in a molecule.
  2. Indicates the charge present on an individual atom in a molecule.
  3. Can be applied to any element or compound.
  4. Represented by Arabic numerals.
  5. Example: The oxidation number of Carbon in Carbon dioxide is +4.
  • Oxidation Number:
  1. Refers to the average of the charges present on all the atoms of an element in a molecule.
  2. Can be applied on the coordination compound.
  3. Represented by Roman numerals.
  4. In any coordination compound, if the central metal atom is bonded in ionic form, then the charge on the central atom signifies the oxidation number.
  5. Example of oxidation number: The oxidation number of Iron in ferrous sulfate (FeSO4) is +2.

In summary, the oxidation state represents the charge on an individual atom in a molecule, while the oxidation number represents the average charge of all atoms of an element in a molecule. Additionally, oxidation state can be applied to any element or compound, whereas oxidation number is mainly used for coordination compounds.

Comparative Table: Oxidation State vs Oxidation Number

The terms "oxidation state" and "oxidation number" are often used interchangeably, but they have slightly different meanings. Here is a table highlighting the differences between the two concepts:

Oxidation State Oxidation Number
Refers to the formal charges on atoms within a molecule or ion Refers to the actual charges on ions in an ionic compound
Assigned according to specific rules, such as electronegativity and covalent bonding Determined by the charge of the ion in an ionic compound
Can be positive, negative, or zero Is always a positive or negative integer
For a pure element, the oxidation state is zero For a pure element, the oxidation number is the same as its charge
Used to describe the distribution of electrons in a molecule or ion Used to describe the charge distribution in an ionic compound

Both oxidation state and oxidation number are useful for understanding and predicting the behavior of elements in chemical reactions, particularly in redox reactions. While oxidation state is more general and can apply to both covalent and ionic compounds, oxidation number is more specific and is directly related to the charge of ions in an ionic compound.