Import Question JSON

$\text{Hint: As the number of unpaired electrons increases, the value of spin magnetic moment increases.}$ $\text{(i) [FeF}_6\text{]}^{3-} \rightarrow \text{Fe}^{3+} \Rightarrow [\text{Ar}] 3d^5$ $\text{Fe}^{3+} \begin{array}{|c|c|c|c|c|} \hline \uparrow & \uparrow & \uparrow & \uparrow & \uparrow \\ \hline \end{array} 3d$ $\text{The F}^- \text{ ion is a weak field ligand hence, the pairing of electrons does not take place. Thus, [FeF}_6\text{]}^{3-} \text{ has 5 unpaired electrons.}$ $n = 5,$ $\mu = \sqrt{n(n+2)}$ $\mu = \sqrt{35} \text{ B.M.}$ $\text{(ii) [Co(NH}_3\text{)}_6\text{]}^{3+} \rightarrow \text{Co}^{3+} \Rightarrow [\text{Ar}] 3d^6$ $\text{In Co}^{3+}, \text{ NH}_3 \text{ acts as a strong field ligand. Hence, the pairing of electrons takes place.}$ $\text{Co}^{3+} \begin{array}{|c|c|c|c|c|c|} \hline \uparrow\downarrow & \uparrow\downarrow & \uparrow\downarrow & \uparrow\downarrow & \uparrow\downarrow & \uparrow\downarrow \\ \hline \end{array} 3d$ $\text{The [Co(NH}_3\text{)}_6\text{]}^{3+} \text{ does not contain unpaired electrons. Hence, it has zero dipole moment.}$ $\text{(iii) [NiCl}_4\text{]}^{2-} \rightarrow \text{Ni}^{2+} \Rightarrow [\text{Ar}] 3d^8$ $\text{The Cl}^- \text{ is a weak field ligand hence, the pairing of electrons did not take place.}$ $\text{Ni}^{2+} \begin{array}{|c|c|c|c|c|c|c|c|} \hline \uparrow\downarrow & \uparrow\downarrow & \uparrow\downarrow & \uparrow & \uparrow \\ \hline \end{array} 3d$ $\text{In [NiCl}_4\text{]}^{2-}, \text{ two unpaired electrons are present. Calculate the value of magnetic moment as follows:}$ $n = 2,$ $\mu = \sqrt{2(2+2)}$ $\mu = \sqrt{8} \text{ B.M.}$