Primary Valence of Iron in Fe4[Fe(CN)6]3 Coordination Entity

The primary valence of iron in the coordination entity of compound Fe4[Fe(CN)6]3 is 2.

Explanation:

- Fe4[Fe(CN)6]3 is a coordination compound containing four iron atoms and three [Fe(CN)6]3- anions.
- In the complex anion [Fe(CN)6]3-, the central iron ion has a coordination number of 6 and is surrounded by six cyanide ligands.
- Each cyanide ligand forms a coordinate covalent bond with the central iron ion, donating a pair of electrons to form a stable complex.
- The iron atoms in the compound Fe4[Fe(CN)6]3 have different oxidation states, namely +2 and +3.
- The iron atoms with oxidation state +3 act as counterions that balance the charge of the complex anion [Fe(CN)6]3-.
- The iron atoms with oxidation state +2 are part of the complex anion [Fe(CN)6]3- and have a primary valence of 2, as they are surrounded by six ligands that form coordinate covalent bonds with them.
- The primary valence of an atom in a coordination compound is the number of ligands that form coordinate covalent bonds with the atom.
- Therefore, the primary valence of iron in the coordination entity of compound Fe4[Fe(CN)6]3 is 2.

Conclusion:

The primary valence of iron in the coordination entity of compound Fe4[Fe(CN)6]3 is 2, which indicates that the iron atoms with oxidation state +2 are surrounded by six ligands that form coordinate covalent bonds with them.