The formula of iron(III) oxide is:

  1. FeO
  2. FeO2
  3. Fe2O
  4. Fe2O3


Iron is present in +3 oxidation state.

The correct answer is: Fe2O3

    • When a metal can have multiple oxidation states, the particular oxidation state in which it exists in that compound in mentioned in binary in the bracket.
    • In the chemical name in binary the oxidation state of the metal is mentioned.
    • Iron is in +3 oxidation state and oxide in -2. To balance out and to make the compound neutral two iron atoms and three oxygen atoms are present.
    • The chemical formula of iron(III) oxide is Fe2O3.