Account for different magnetic behaviour of hexacyanoferrate (III) and hexafluoroferrate (III).

Explanation

In `[Fe(CN)_(6)]^(3-),CN^(-)` is a strong ligand. Hence, electrons in the d-subshell pair up and there is only one unpaired electron left. In `[FeF_(6)]^(3-)`, `F^(-)` is a weak ligand. Hence, electrons in the 3d subshell do not pair up. There are five unpaired electrons in the 3d-subshell. (The hybridisation involved is `sp^(3)d^(2)` outer orbital complex is formed). Hence `[FeF_(6)]^(3-)` has greater magnetic moment than `[Fe(CN)_(6)]^(3-)`.