The spin only magnetic moment of `[MnBr_4]^(2-)` is 5.9BM. Predict the geometry of the complex ion.

Explanation

Since the coordination number of `Mn^(2+)` ion in the complex ion is 4, the geometry may be either tetrahedral `(sp^(3))` or square planar `(dsp^(2))`. But the fact that the magnetic moment of the complex ion is 5.9BM, it should be tetrahedral in shape but not square planar. This is because of the presence of 5 unpaired electrons in the d-orbitals.