Question

Compare qualitatively color of complexes (in wavelength): [fef6]3- and [fef6]4-

Answer 1

In [FeF6]3?, F? is a weak ligand and cannot cause pairing in Fe3+. So the other nd orbitals are involved in hybridization (sp3d2). The complex has octahedral geometry. It is paramagnetic in nature due to the presence of five unpaired electrons