Question

The number of paramagnetic metal complex species among \([Co(NH_3)_6]^{3+} , [Co(C_2O_4)_3]^{3-} , [MnCl_6]^{3-},\) \( [Mn(CN)_6]^{3-}, [CoF_6]^{3-} , [Fe(CN)_6]^{3-}\) and \([FeF_6]^{3-}\) with same number of unpaired electrons is ______.

Answer 1

Answer is: 2

\(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+} \Rightarrow \mathrm{Co}^{3+}, \mathrm{d}^6, \mathrm{t}_{2 \mathrm{g}}^6 \mathrm{e}_{\mathrm{g}}^0 \Rightarrow \text{diamagnetic}\)      

\(\left[\mathrm{Co}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-} \Rightarrow \mathrm{Co}^{3+}, \mathrm{d}^6, \mathrm{t}_{2 \mathrm{g}}^6 \mathrm{e}_{\mathrm{g}}^0 \Rightarrow \text{diamagnetic}\)

\(\left[\mathrm{MnCl}_6\right]^{3-} \Rightarrow \mathrm{Mn}^{3+}, \mathrm{d}^4, \mathrm{t}_{2 \mathrm{g}}^3 \mathrm{e}_{\mathrm{g}}^1 \Rightarrow \text{4 unpaired electron, paramagnetic}\)

\(\left[\mathrm{CoF}_6\right]^{3-} \Rightarrow \mathrm{Co}^{3+}, \mathrm{d}^6, \mathrm{t}_{2 \mathrm{g}}^4 \mathrm{e}_{\mathrm{g}}^2 \Rightarrow \text{4 unpaired electron, paramagnetic}\)

\(\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-} \Rightarrow \mathrm{Fe}^{3+}, \quad \mathrm{d}^5, \quad \mathrm{t}_{2 \mathrm{g}}^5 \mathrm{e}_{\mathrm{g}}^0 \Rightarrow \text{1 unpaired electron, paramagnetic}\)

\(\left[\mathrm{FeF}_6\right]^{3-} \Rightarrow \mathrm{Fe}^{3+}, \mathrm{d}^5, \mathrm{t}_{2 \mathrm{g}}^3 \mathrm{e}_{\mathrm{g}}^2 \Rightarrow \text{5 unpaired electron}\)