Why Fe3+ is more stable the Fe2+?

?”, you are going to solve this puzzle. There is a great difference between the Fe2+ and Fe3+. These may differ in there oxidation state, physical and chemical properties.  They may also differ in there names. Fe2+ is Ferrous and Fe3+ is Ferric. The compounds of Fe2+ and Fe3+ are ionic in nature. They are linked by the ionic bond.




  • It is pale yellow and turns to violet when reacting with water. 
  • Fe2+ shows the paramagnetic property. If it forms a low spin complex it may be diamagnetic. Paramagnetic property is the property that shows that it has an unpaired electron in its outermost shell.
  • Fe2+ oxidizes to the Fe3+ ion in the presence of KMnO4, HNO3. In addition to KMnO4, the pink color of it decolorizes that shows exact oxidation of Fe2+.
  • Another colored complexes test to distinguish between Fe2+ and Fe3+ is that Fe2+ form a red-orange color when reacting with amine ligands.

Fe3+ (Ferric):

  • It is yellow brown when reacting with the water.
  • Fe3+ shows the paramagnetic behavior. 
  • Fe3+ gives the read solution when reacting with the thiocyanate ions. This method is used to flake blood in the movies and films.
  • The basic difference between the Fe2+ and Fe3+ is of number of electrons. 

General configuration of Fe:

Iron is the chemical element wth the atomic number 26. Its oxidation states ranges from -2 to +6. But now here i will illutsrate the configuration of Fe2+ and Fe3+. general configuration of Fe is [Ar] 3d6, 4s2.

Fe2+ and Fe3+

Reason Why Fe3+ is more stable than Fe2+?

If we imagine the electronic configuration of  Fe2+ and Fe3+ we should observe that Fe3+ is more stable. In the configuration of Fe2+ the 2 electrons are removes from 4s orbital because nucleus attracts other prior orbitals with more attraction so it is easy to remove. on the other hand the half filled and completely filled orbitals are more stable than that of partially filled. so in configuration of Fe3+ there is half filled d orbital and in Fe2+ there is partially filled d orbital. there configuration is given below:
Completely filled or half filled > partially filled.


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