Orbitals involved in hybridization of [Fe(CN)6]4-
Hybridization is a concept in chemistry that involves mixing atomic orbitals to form new hybrid orbitals. In the case of the complex ion [Fe(CN)6]4-, the central metal ion (Fe) undergoes hybridization to form hybrid orbitals for bonding with the ligands (CN-).

d Orbitals involved in hybridization
- In the case of [Fe(CN)6]4-, the central Fe(II) ion is typically in a +2 oxidation state, which implies the presence of 6 d electrons.
- The d orbitals (dxy, dyz, dzx, dx2-y2, dz2) of Fe are involved in hybridization to form hybrid orbitals.

s and p Orbitals involved in hybridization
- The ligands in [Fe(CN)6]4- are cyanide ions (CN-), which are strong-field ligands.
- The cyanide ligands have a lone pair of electrons on the carbon atom, which can interact with the empty d orbitals of Fe through sigma bonding.
- The s and p orbitals of the cyanide ligands are involved in forming sigma bonds with the hybrid orbitals of Fe.

Explanation
- In the hybridization process, the d orbitals of Fe mix with the s and p orbitals of the ligands to form a set of hybrid orbitals that are used for bonding.
- The hybrid orbitals allow for better overlap between the metal ion and the ligands, leading to stronger bonding interactions.
- This hybridization process influences the geometry of the complex ion and affects its magnetic properties and reactivity.
In conclusion, in the complex ion [Fe(CN)6]4-, the d orbitals of Fe hybridize with the s and p orbitals of the cyanide ligands to form hybrid orbitals for bonding. This hybridization is essential for the stability and properties of the complex.