In which of the following complexes is the pairing of $(n-1)d$ electrons $NOT$ present in the presence of strong field ligands $(SFL)$?

The coordination number of $Ni^{2+}$ is $4$.
$NiCl_2 + KCN$ (excess) $\rightarrow A$ (cyano complex)
$NiCl_2 + \text{Conc. } HCl$ (excess) $\rightarrow B$ (chloro complex)
$1.$ The $IUPAC$ names of $A$ and $B$ are:
$(A)$ Potassium tetracyanonickelate $(II)$,potassium tetrachloronickelate $(II)$
$(B)$ Tetracyanopotassiumnickelate $(II)$,tetrachloropotassiumnickelate $(II)$
$(C)$ Tetracyanonickel $(II)$,tetrachloronickel $(II)$
$(D)$ Potassium tetracyanonickel $(II)$,potassium tetrachloronickel $(II)$
$2.$ Predict the magnetic nature of $A$ and $B$:
$(A)$ Both are diamagnetic.
$(B)$ $A$ is diamagnetic and $B$ is paramagnetic with one unpaired electron.
$(C)$ $A$ is diamagnetic and $B$ is paramagnetic with two unpaired electrons.
$(D)$ Both are paramagnetic.
$3.$ The hybridization of $A$ and $B$ are:
$(A)$ $dsp^2, sp^3$
$(B)$ $sp^3, sp^3$
$(C)$ $dsp^2, dsp^2$
$(D)$ $sp^3 d^2, d^2 sp^3$
Give the answers for questions $1, 2$ and $3$.

Select the correct code about complex $[Cr(NO_2)(NH_3)_5][ZnCl_4]$:
$(I)$ $IUPAC$ name of compound is pentaamminenitrito$-N$-chromium$(III)$ tetrachlorozincate$(II)$
$(II)$ It shows geometrical isomerism
$(III)$ It shows linkage isomerism
$(IV)$ It shows coordination isomerism

Choose the correct statement$(s)$ among the following:
$(A)$ $[FeCl_4]^-$ has tetrahedral geometry.
$(B)$ $[Co(en)(NH_3)_2Cl_2]^+$ has $2$ geometrical isomers.
$(C)$ $[FeCl_4]^-$ has higher spin-only magnetic moment than $[Co(en)(NH_3)_2Cl_2]^+$.
$(D)$ The cobalt ion in $[Co(en)(NH_3)_2Cl_2]^+$ has $sp^3d^2$ hybridization.

Which of the following change the colour of the aqueous solution of $FeCl_3$?

Given below are two statements:
Statement-$I$: Hybridisation,shape,and spin-only magnetic moment of $K_{3}[Co(CO_{3})_{3}]$ are $sp^{3}d^{2}$,octahedral,and $4.9 \ BM$ respectively.
Statement-$II$: Geometry,hybridisation,and spin-only magnetic moment values $(BM)$ of the ions $[Ni(CN)_{4}]^{2-}$,$[MnBr_{4}]^{2-}$,and $[CoF_{6}]^{3-}$ respectively are square planar,tetrahedral,octahedral; $dsp^{2}$,$sp^{3}$,$sp^{3}d^{2}$ and $0, 5.9, 4.9$.