Among $(a) - (d)$,the complexes that can display geometrical isomerism are:
$(a) [Pt(NH_3)_3 Cl]^+$
$(b) [Pt(NH_3) Cl_5]^-$
$(c) [Pt(NH_3)_2 Cl(NO_2)]$
$(d) [Pt(NH_3)_4 ClBr]^{2+}$

Which of the following is not correctly matched?

The spin magnetic moment of cobalt in $Hg[Co(SCN)_4]$ is

The correct order of the spin only magnetic moment of metal ions in the following low spin complexes,$[V(CN)_6]^{4-}$,$[Fe(CN)_6]^{4-}$,$[Ru(NH_3)_6]^{3+}$,and $[Cr(NH_3)_6]^{2+}$,is

Number of paramagnetic complexes among the following is . . . . . . . $[MnBr_4]^{2-}$, $[NiCl_4]^{2-}$, $[Ni(CN)_4]^{2-}$, $[Ni(CO)_4]$, $[CoF_6]^{3-}$, $[Fe(CN)_6]^{4-}$, $[Mn(CN)_6]^{3-}$, $[Ti(CN)_6]^{3-}$, $[Cu(H_2O)_6]^{2+}$, $[Co(C_2O_4)_3]^{3-}$

The $[Cr(NH_3)_6]^{3+}$ ion is ...