What type of isomerism is exhibited by $[Cr(H_2O)_6]Cl_3$ and $[Cr(H_2O)_5Cl]Cl_2 \cdot H_2O$?

The magnetic moment of $Ni^{2+}$ in an aqueous solution is ......... $B.M.$

The number of isomers of $[Co(dien)Cl_3]$ is

Correct increasing order of spin magnetic moment $($in $B.M.)$ for the following complexes is:
$(I) \ [FeF_6]^{3-} \ (II) \ [V(H_2O)_6]^{2+} \ (III) \ [Fe(H_2O)_6]^{2+}$

In the nitroprusside ion,the iron exists as $Fe^{2+}$ and $NO$ as $NO^{+}$ rather than $Fe^{3+}$ and $NO$ respectively. These forms of ions are established with the help of

Magnetic moment of $[Cu(NH_3)_4]^{2+}$ ion is (in $B.M.$)