The number of geometrical isomers for octahedral $[CoCl_4(NH_3)_2]^-$,square planar $[AuBr_2Cl_2]^-$ and $[PtCl_2(en)]$ are

What is the calculated value of spin-only magnetic moment in terms of $BM$ if only one unpaired electron is present in a species?

Arrange the following complexes in the increasing order of their spin only magnetic moment (in $B.M$):
$I$. $[Fe(CN)_6]^{4-}$
$II$. $[MnCl_4]^{2-}$
$III$. $[Mn(CN)_6]^{4-}$
$IV$. $[Cr(NH_3)_6]^{3+}$

$[CoCl_2(NH_3)_4]^+ + Cl^- \to [CoCl_3(NH_3)_3] + NH_3$. If in this reaction two isomers of the product are obtained,which is true for the initial (reactant) complex?

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

Consider the following isomerism:
$i$. Ionization
$ii$. Hydrate
$iii$. Coordination
$iv$. Geometrical
$v$. Optical
Which of the above isomerisms are exhibited by $[Cr(NH_3)_2(OH)_2Cl_2]^-$?