The total possible coordination isomers for the following compounds respectively are :
$[Co(en)_3] [Cr(C_2O_4)_3]$
$[Cu(NH_3)_4] [CuCl_4]$
$[Ni(en)_3] [Co(NO_2)_6]$

The 'spin only' magnetic moment value of $MO_4^{2-}$ is . . . . . $BM$. (Where $M$ is a metal having least metallic radii among $Sc, Ti, V, Cr, Mn$ and $Zn$).
(Given atomic number: $Sc=21, Ti=22, V=23, Cr=24, Mn=25$ and $Zn=30$)

The "spin only" magnetic moment of $Ni^{2+}$ in aqueous solution would be [At. no. of $Ni = 28$]

$A$ metal complex with a formula $MCl_4 \cdot 3NH_3$ is involved in $sp^3d^2$ hybridisation. It upon reaction with excess of $AgNO_3$ solution gives '$x$' moles of $AgCl$. Consider '$x$' is equal to the number of lone pairs of electron present in the central atom of $BrF_5$. Then the number of geometrical isomers exhibited by the complex is $............$

How many geometrical isomers are possible for the complex $[Ma_3b_3]^{\pm n}$?

Match List-$I$ with List-$II$ :

List-$I$ (Complexes)	List-$II$ (Types)
$a$. $[Co(NH_3)_5NO_2]Cl_2$ and $[Co(NH_3)_5ONO]Cl_2$	$i$. Linkage isomerism
$b$. $[Cr(NH_3)_6][Co(CN)_6]$ and $[Cr(CN)_6][Co(NH_3)_6]$	$ii$. Coordination isomerism
$c$. $[Co(NH_3)_5(SO_4)]Br$ and $[Co(NH_3)_5Br]SO_4$	$iii$. Ionisation isomerism
$d$. $[Cr(H_2O)_6]Cl_3$ and $[Cr(H_2O)_5Cl]Cl_2 \cdot H_2O$	$iv$. Solvate isomerism

Choose the correct answer from the options given below :