$A$ mixture $X$ containing $0.02 \, mol$ of $[Co(NH_3)_5SO_4]Br$ and $0.02 \, mol$ of $[Co(NH_3)_5Br]SO_4$ is dissolved in water to make a $2 \, L$ solution.
$1 \, L \, of \, X + \text{Excess of } AgNO_3 \rightarrow Y \, mol \, of \, ppt.$
$1 \, L \, of \, X + \text{Excess of } BaCl_2 \rightarrow Z \, mol \, of \, ppt.$
Then $Y$ and $Z$ are respectively ...............

The reaction of aqueous $[Ni(H_2O)_6]^{2+}$ is performed by the addition of a bidentate ligand ethane-$1,2$-diamine $(en)$. Match the following:

$[Ni(H_2O)_6]^{2+} : en$ molar ratio	Colour of the product
$A. 1:1$	$I. \text{Pale blue}$
$B. 1:2$	$II. \text{Blue/Purple}$
$C. 1:3$	$III. \text{Violet}$

The correct match is:

Match each coordination compound in List-$I$ with an appropriate pair of characteristics from List-$II$ and select the correct answer using the code given below the lists.
$\{ en = H_2NCH_2CH_2NH_2 \}$; atomic numbers: $\{Ti = 22; Cr = 24; Co = 27; Pt = 78\}$

List-$I$	List-$II$
$P.$ $[Cr(NH_3)_4Cl_2]Cl$	$1.$ Paramagnetic and exhibits ionisation isomerism
$Q.$ $[Ti(H_2O)_5Cl](NO_3)_2$	$2.$ Diamagnetic and exhibits cis-trans isomerism
$R.$ $[Pt(en)(NH_3)_2Cl_2]NO_3$	$3.$ Paramagnetic and exhibits cis-trans isomerism
$S.$ $[Co(NH_3)_4(NO_3)_2]NO_3$	$4.$ Diamagnetic and exhibits ionisation isomerism
Codes: $P, Q, R, S$

Which of the following statements is correct?

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 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: