\begin{aligned} &\text { Sol. }\\ &\begin{array}{llc} & & \text { Unpaired } e^{-} \\ {\left[\mathrm{Fe}(\mathrm{CN})_8\right]^{3-}} & \mathrm{Fe}^{+3} \Rightarrow \mathrm{t}_2 \mathrm{~g}^5 \mathrm{eg}^0, & 1 \\ {\left[\mathrm{Mn}(\mathrm{CN})_8\right]^{3-}} & \mathrm{Mn}^{+3} \Rightarrow \mathrm{t}_2 \mathrm{~g}^4 \mathrm{eg}^0, & 2 \\ {\left[\mathrm{CoF}_6\right]^{3-}} & \mathrm{Co}^{+3} \Rightarrow \mathrm{t}_2 \mathrm{~g}^4 \mathrm{eg}^2, & 4 \\ {\left[\mathrm{MnBr}_4\right]^{2-}} & \mathrm{Mn}^{+2} \Rightarrow \mathrm{e}^2 \mathrm{t}_2^3, & 5 \\ \text { Spin magnetic moment } \mu=\sqrt{\mathrm{n}(\mathrm{n}+2)} \text { B.M } \end{array} \end{aligned}