Which of the following ions has a magnetic moment of $5.93 \ BM$?

The total number of possible isomers for the complex compound $[Cu^{II}(NH_3)_4][Pt^{II}Cl_4]$ are

Write all the geometrical isomers of $[Pt(NH_3)(Br)(Cl)(Py)]$ and determine how many of these will exhibit optical isomerism.

Draw the structures of optical isomers of:
$(i)$ $[Cr(C_2O_4)_3]^{3-}$
$(ii)$ $[PtCl_2(en)_2]^{2+}$
$(iii)$ $[Cr(NH_3)_2Cl_2(en)]^{+}$

The number of paramagnetic metal complex species among $[Co(NH_3)_6]^{3+}$,$[Co(C_2O_4)_3]^{3-}$,$[MnCl_6]^{3-}$,$[Mn(CN)_6]^{3-}$,$[CoF_6]^{3-}$,$[Fe(CN)_6]^{3-}$ and $[FeF_6]^{3-}$ with the same number of unpaired electrons is $............$

Amongst $TiF_6^{2-}$,$CoF_6^{3-}$,$Cu_2Cl_2$,and $NiCl_4^{2-}$ (Atomic numbers: $Ti=22, Co=27, Cu=29, Ni=28$),the colourless species are: