Identify the metal ions among Co ^ 2+ , Ni ^ 2+ , Fe ^ 2+ , V ^ 3+ and Ti ^ 2+ having a spin-only magnetic moment value more than 3.0 BM. The sum of unpaired electrons present in the high spin octahedral complexes formed by those metal ions is \_\_\_\_.
A. A
The spin-only magnetic moment is given by = n(n+2) BM, where n is the number of unpaired electrons. For > 3.0 BM, n must be 3 (since for n=2, = 8 2.83 BM and for n=3, = 15 3.87 BM). Electronic configurations and unpaired electrons (n) in high spin octahedral complexes: Metal Ion Configuration n (BM) Co^ 2+ [Ar] 3d^7 3 3.87 Ni^ 2+ [Ar] 3d^8 2 2.83 Fe^ 2+ [Ar] 3d^6 4 4.90 V^ 3+ [Ar] 3d^2 2 2.83 Ti^ 2+ [Ar] 3d^2 2 2.83 The metal ions with > 3.0 BM are Co^ 2+ (n=3) and Fe^ 2+ (n=4). The sum of unpaired electrons for these ions is 3 + 4 = 7.
Related: Chemistry — Coordination Compounds · All PYQ Banks