The tendency to form complexes increases with ..........

Assign $A, B, C, D$ from the given type of reaction.
$Fe(CN)_2 \downarrow + 4KCN \longrightarrow K_4[Fe(CN)_6]$

$5.33 \text{ g}$ of $CrCl_3 \cdot 6H_2O$, which is a $1:3$ electrolyte, is dissolved in water and passed through a cation exchanger. The chloride ions in the eluted solution, on treatment with $AgNO_3$, result in $8.61 \text{ g}$ of $AgCl$. The ratio of moles of complex reacted and moles of $AgCl$ formed is . . . . . . $\times 10^{-2}$. (Nearest integer) [Molar mass in $\text{g mol}^{-1}$: $Cr = 52, Ag = 108, Cl = 35.5, H = 1, O = 16$]

The solubility of $AgCl$ in $NH_4OH$ is due to the formation of:

Select the correct statement regarding the $[Ni(DMG)_2]$ complex compound.

Assign $A, B, C, D$ from the given type of reaction: $AgI \downarrow + 2Na_2S_2O_3 \longrightarrow Na_3[Ag(S_2O_3)_2] + NaI$