Consider that d 6 metal ion M 2 + forms a complex with aqua ligands, and the spin only magnetic moment of…

Consider that d6 metal ion M2+ forms a complex with aqua ligands, and the spin only magnetic moment of the complex is 4.90BM. The geometry and the crystal field stabilization energy of the complex is :
  1.  octahedral and -2.4Δ0+2P
  2. tetrahedral and 0.6Δt
  3.  octahedral and -1.6Δ0
  4.  tetrahedral and -1.6Δt+1P

Solution

Since spin only magnetic moment is 4.90 BM so number of unpaired electrons must be 4. There are two possibilities:

(1) If the complex is octahedral, then it has to be high spin complex with configuration t2g2,1,1eg1,1, in that case CFSE=4×-0.4Δ0+2×0.6Δ0=-0.4Δ0
(2) If the complex is tetrahedral then its electronic configuration will be =egt2g2,11,1,1 and CFSE will be=3X -0.6Δt+3X0.4Δt=-0.6Δt

Asked in: JEE Main 2020 (02 Sep Shift 1)

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