(i) $\mathrm{K[Cr(H_2O)_2(C_2O_4)_2]}\cdot 3\mathrm{H_2O}$ : Potassiumdiaquadioxalatochromate(III) hydrate Oxidation state = +3; C.N. = 6; configuration = t${}^3$${}_2g$$\mu=\sqrt{n(n+2)}$ $=\sqrt{3 \times 5}$ $=\sqrt{15}$ $=3.87\,\text{B.M.}$ (ii)$\mathrm{[Co(NH_3)_5Cl]Cl_2}$ : Pentaamminechloridocobalt(III) chloride $\mathrm{Co}(27) : 4s^{2} 3d^{7} ; \mathrm{Co}^{3+} : 4s^{0} 3d^{6}$The oxidation state of Co = +3C.N. = 6; Configuration = t${}^6$ ${}_2g;\ \mu$ = 0 B.M.(iv) $\mathrm{Cs[FeCl_4]}$ : Trichloridotripyridinechromium (III) Coordination No. of Cr = 6; Oxidation state = +3; Configuration = t${}^3$${}_2g$;$\mathrm{Cr}(24) : 4s^{1} 3d^{5} ; \mathrm{Cr}^{3+} : 4s^{0} 3d^{3}$ $\mu=\sqrt{n(n+2)}$$=\sqrt{15}$$=3.87\,\text{B.M.}$(iv) $\mathrm{Cs[FeCl_4]}$: Caesiumtetrachloridoferrate III)Oxidation state = +3; Coordination No. = 4; Configuration = t${}^3$${}_2g$ e${}^2$${}_g$Fe $\mathrm{Fe}(26) : 4s^{2} 3d^{6} ; \mathrm{Fe}^{3+} : 4s^{0} 3d^{5}$ It is paramagnetic due to presence of 5 unpaired electrons.$\mu=\sqrt{n(n+2)}$$=\sqrt{5 \times 7}$$=\sqrt{35}$$=5.92\,\text{B.M.}$;(v) $\mathrm{K_4[Mn(CN)_6]}$ : Potassium hexacyanomanganese(II)Oxidation state = +2; Coordination no. = 6; Configuration = $t_{2g}^{5}$; Mn(25) $:\,[\mathrm{Ar}] 4s^{2} 3d^{5} ; \mathrm{Mn}^{2+} :\,[\mathrm{Ar}] 4s^{0} 3d^{5}$ $\mu=\sqrt{n(n+2)}$$=\sqrt{\sqrt{1 \times 3}}$$=1.732\,\text{B.M.}$