The complexes $[Co(NH_3)_5Br]SO_4$ and $[Co(NH_3)_5SO_4]Br$ are examples of which type of isomerism?

Which of the following is not correctly matched?

Which of the following pairs of isomers and their types of isomerism are correctly matched?
$1.$ $[Co(NH_3)_5NO_2]Cl_2$ and $[Co(NH_3)_5ONO]Cl_2$ $-$ Linkage
$2.$ $[Cu(NH_3)_4] [PtCl_4]$ and $[Pt(NH_3)_4] [CuCl_4]$ $-$ Coordination
$3.$ $[Pt(NH_3)_4Cl_2]Br_2$ and $[Pt(NH_3)_4Br_2]Cl_2$ $-$ Ionization

The number of possible stereoisomers for the complex $[Co(en)_2Cl_2]Cl$ is $(en = \text{ethylenediamine})$.

The calculated spin-only magnetic moments of $[Cr(NH_3)_6]^{3+}$ and $[CuF_6]^{3-}$ in $BM$,respectively,are (Atomic numbers of $Cr$ and $Cu$ are $24$ and $29$,respectively).

The calculated magnetic moments (spin only value) for species $[FeCl_{4}]^{2-}$,$[Co(C_{2}O_{4})_{3}]^{3-}$ and $MnO_{4}^{2-}$ respectively are ..... .