Identify the correct set from the following table:

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 sum of the total number of $Cr-O$ bonds in chromate $(CrO_4^{2-})$ and dichromate $(Cr_2O_7^{2-})$ ions 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
$R$. $[Pt(en)(NH_3)Cl]NO_3$	$3$. Paramagnetic and exhibits cis-trans isomerism
$S$. $[Co(NH_3)_4(NO_3)_2]NO_3$	$4$. Diamagnetic and exhibits ionisation isomerism

$1\,L, 0.02\,M$ solution of $[Co(NH_3)_5SO_4]Br$ is mixed with $1\,L, 0.02\,M$ solution of $[Co(NH_3)_5Br]SO_4$. The resulting solution is divided into two equal parts $(X)$ and treated with excess $AgNO_3$ solution and $BaCl_2$ solution respectively as shown below:
$1\,L$ Solution $(X) + AgNO_3$ solution (excess) $\rightarrow Y$
$1\,L$ Solution $(X) + BaCl_2$ solution (excess) $\rightarrow Z$
The number of moles of $Y$ and $Z$ respectively are:

Match the following:

Column-$1$ (Reaction)	Column-$2$ (Main product)
$A$. $4FeCl_3 + 3K_4[Fe(CN)_6] \rightarrow$	$I$. $Fe_4[Fe(CN)_6]_3$
$B$. $ZnCl_2 + 4NaOH \rightarrow$	$V$. $Na_2ZnO_2$
$C$. $2FeCl_3 + H_2S \rightarrow$	$II$. $FeCl_2$