The correct statements from the following are:
$A$. The strength of anionic ligands can be explained by crystal field theory.
$B$. Valence bond theory does not give a quantitative interpretation of kinetic stability of coordination compounds.
$C$. The hybridization involved in the formation of $\left[Ni(CN)_4\right]^{2-}$ complex is $dsp^2$.
$D$. The number of possible isomer$(s)$ of $cis-\left[PtCl_2(en)_2\right]^{2+}$ is one.
Choose the correct answer from the options given below:

Write down the $IUPAC$ name for each of the following complexes and indicate the oxidation state,electronic configuration,and coordination number. Also,give the stereochemistry and magnetic moment of the complex:
$(i)$ $K[Cr(H_2O)_2(C_2O_4)_2] \cdot 3H_2O$
$(ii)$ $[Co(NH_3)_5Cl]Cl_2$
$(iii)$ $CrCl_3(py)_3$
$(iv)$ $Cs[FeCl_4]$
$(v)$ $K_4[Mn(CN)_6]$

The correct option(s) about entropy $(S)$ is(are)
$[R =$ gas constant, $F =$ Faraday constant, $T =$ Temperature $]$
$(A)$ For the reaction, $M_{(s)} + 2H^{+}_{(aq)} \rightarrow H_{2(g)} + M^{2+}_{(aq)}$, if $\frac{dE_{cell}}{dT} = \frac{R}{F}$, then the entropy change of the reaction is $R$ (assume that entropy and internal energy changes in entropy and internal energy are temperature independent).
$(B)$ The cell reaction, $Pt_{(s)} \mid H_2(g, 1 \ bar) \mid H^{+}(aq, 0.01 \ M) \parallel H^{+}(aq, 0.1 \ M) \mid H_2(g, 1 \ bar) \mid Pt_{(s)}$, is an entropy driven process.
$(C)$ For racemization of an optically active compound, $\Delta S > 0$.
$(D)$ $\Delta S > 0$, for $[Ni(H_2O)_6]^{2+} + 3en \rightarrow [Ni(en)_3]^{2+} + 6H_2O$ (where $en =$ ethylenediamine).

The volume (in $mL$) of $0.125\; M\; AgNO_{3}$ required to quantitatively precipitate chloride ions in $0.3\; g$ of $[Co(NH_{3})_{6}]Cl_{3}$ is (Given: $M_{[Co(NH_{3})_{6}]Cl_{3}} = 267.46\; g/mol$,$M_{AgNO_{3}} = 169.87\; g/mol$).

The given complex $M(ABCDEF)$ exhibits which of the following isomerism?

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 $3$.