What is the oxidation number for iron?

The oxidation number of iron can vary depending on the compound it is in. The most common oxidation states for iron are +2 and +3.

Common Oxidation States

• Iron(II) or Ferrous: This state has an oxidation number of +2. It occurs in compounds like FeO and FeSO4.
• Iron(III) or Ferric: This state has an oxidation number of +3. It is found in compounds such as Fe2O3 and FeCl3.

Determining Oxidation Numbers

To find the oxidation number of iron in a specific compound, you can use the rules for assigning oxidation states. For example, in FeCl3, chlorine has an oxidation number of -1, which helps determine that iron must be +3 to balance the charges.

Other Oxidation States

While +2 and +3 are the most common, iron can also exhibit other oxidation states, such as +6 in some rare compounds. However, these are less frequently encountered.