Class 12 NEET Chemistry Coordination Compounds

The electronic configuration of $\mathrm{V}(23)=[\mathrm{Ar}]\,4s^{2},\ 3d^{3}$ Let in $[\mathrm{V}(\mathrm{gly})_2(\mathrm{OH})_2(\mathrm{NH}_3)_2]^{+}$oxidation state of $\mathrm{V}$ is $x$. $x+(-1)\times 2+(-1)2+(0\times 2)=+1$ $x=+5$ $\mathrm{V}^{5+}=[\mathrm{Ar}]\,4s^{0},\ 3d^{0}$ (no unpaired electrons) The electronic configuration of $\mathrm{Fe}(26)=[\mathrm{Ar}]\,4s^{2},\ 3d^{6}$ Let the oxidation state of $[\mathrm{Fe}(\mathrm{en})(\mathrm{ppy})(\mathrm{NH}_3)_2]^{2+}$ is $x$. $[x+(0)+(0)+(0)\times 2]=+2$ $x=+2$ $\mathrm{Fe}^{2+}=[\mathrm{Ar}],\ 3d^{6}(\because 4$ unpaired electron) but, bpy, en and $\mathrm{NH}_3$ all are strong field ligands, so pairing occurs and thus, $\mathrm{Fe}^{2+}$ contains no unpaired electron The electronic configuration of $\mathrm{Co}(27)=[\mathrm{Ar}]\,4s^{2},\ 3d^{7}$ Let the oxidation state $\mathrm{Co}$ in $[\mathrm{Co}(\mathrm{ox})_2(\mathrm{OH})_2]^{-}$is $x$ $x+(-2)\times 2+(-1)\times 2=-1$ $x=+5$ $\mathrm{Co}^{5+}=[\mathrm{Ar}]\,.3d^{4}[4$ unpaired electrons] ox and OH are weak field ligands, thus pairing of electron units does not occur. The electronic configuration of $\mathrm{Ti}(22)=[\mathrm{Ar}]\,4s^{2},\ 3d^{2}$ Oxidation state of Ti in $[\mathrm{Ti}(\mathrm{NH}_3)_6]^{3+}$ is 3 . $\mathrm{Ti}^{3+}=[\mathrm{Ar}]\,3d^{1}$ (one unpaired electron) Hence, complex $[\mathrm{Co}(\mathrm{ox})_2(\mathrm{OH})_2]^{-}$has maximum number of unpaired electrons, thus show maximum paramagnetism