H2O is a strong field ligand, resulting in d2sp3 hybridization with no unpaired electrons.

H2O is a weak field ligand, resulting in sp3d2 hybridization with four unpaired electrons in the 3d orbitals of Fe2+.

H2O is a strong field ligand, resulting in sp3d2 hybridization with two unpaired electrons in the 3d orbitals of Fe2+.

H2O is a weak field ligand, resulting in dsp2 hybridization with two unpaired electrons in the 3d orbitals of Fe2+.

Sigma bond

Pi bond

Ionic bond

Hydrogen bond

$sp^3$ hybridization with bond angles of $109.5^\circ$.

$sp^3d$ hybridization with bond angles of exactly $90^\circ$ and $120^\circ$.

$sp^3d^2$ hybridization with bond angles of $90^\circ$.

$sp^3d$ hybridization with bond angles of approximately $102^\circ$ and $173^\circ$ due to lone pair repulsion.

$sp^3$ hybridization with $CN^-$ as a weak field ligand.

$dsp^2$ hybridization with $CN^-$ as a strong field ligand.

$sp^3d^2$ hybridization with $CN^-$ as a weak field ligand.

$d^2sp^3$ hybridization with $CN^-$ as a strong field ligand.

It is diamagnetic and inner orbital complex

It is diamagnetic and outer orbital complex

It is paramagnetic and inner orbital complex

It is paramagnetic and outer orbital complex

$sp^3$

$sp^2$

$sp$

$dsp^2$

Electrovalent

Hydrogen

Covalent

Coordinate

H2O is a strong field ligand, resulting in d2sp3 hybridization with no unpaired electrons.

H2O is a weak field ligand, resulting in sp3d2 hybridization with four unpaired electrons in the 3d orbitals of Fe2+.

H2O is a strong field ligand, resulting in sp3d2 hybridization with two unpaired electrons in the 3d orbitals of Fe2+.

H2O is a weak field ligand, resulting in dsp2 hybridization with two unpaired electrons in the 3d orbitals of Fe2+.

+2

0

-2

+4

$sp^3$

$dsp^2$

$d^2sp^3$

$sp^3d^2$

4 sigma and 2 pi

5 sigma and 1 pi

6 sigma and 0 pi

1 sigma and 5 pi