Consider the following complexes : 

(I) ${\mathrm{K}}_2{\mathrm{PtCl}}_6$

(II) ${\mathrm{PtCl}}_4.2{\mathrm{NH}}_3$

(III) ${\mathrm{PtCl}}_4.3{\mathrm{NH}}_3$

(IV) ${\mathrm{PtCl}}_4.5{\mathrm{NH}}_3$

Their electrical conductances in aqueous solution are :

The volume $\left(\mathrm{i}\mathrm{n} \mathrm{m}\mathrm{L}\right)$ of $0.125 \mathrm{M} {\mathrm{A}\mathrm{g}\mathrm{N}\mathrm{O}}_3$ required to quantitatively precipitate chloride ions in $0.3\mathrm{g}$ of $\left[\mathrm{C}\mathrm{o}{\left(\mathrm{N}{\mathrm{H}}_3\right)}_6\right]\mathrm{C}{\mathrm{l}}_3$ is __________.
${}^{\mathrm{M}}\left[\mathrm{C}\mathrm{o}{\left(\mathrm{N}{\mathrm{H}}_3\right)}_6\right]\mathrm{C}{\mathrm{l}}_3=267.46\mathrm{g}/\mathrm{m}\mathrm{o}\mathrm{l}$
${{}^{\mathrm{M}}\mathrm{A}\mathrm{g}\mathrm{N}\mathrm{O}}_3=169.87\mathrm{g}/\mathrm{m}\mathrm{o}\mathrm{l}$

Report the nearest integer as the answer.

Addition of excess of ${\mathrm{AgNO}}_3$ to an aqueous solution of $1$ mole of ${\mathrm{PdCl}}_2·4{\mathrm{NH}}_3$ gives $2$ moles of $\mathrm{AgCl}$. The conductivity of this solution corresponds to:

On complete reaction of ${\mathrm{FeCl}}_3$ with oxalic acid in aqueous solution containing $\mathrm{KOH}$, resulted in the formation of product $\mathrm{A}$. The secondary valency of Fe in the product A is ______ .

(Round off to the Nearest Integer).