The oxidation states of $\mathrm{Cr}$ in $\left[\mathrm{Cr}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\mathrm{Cl}}_3$, $\left[\mathrm{Cr}{\left({\mathrm{C}}_6{\mathrm{H}}_6\right)}_2\right]$ and ${\mathrm{K}}_2\left[\mathrm{Cr}\left(\mathrm{CN}{)}_2{\left({\mathrm{O}}_2\right)}_2\right(\mathrm{O}{)}_2\left({\mathrm{NH}}_3\right)\right]$ respectively are:

Given the ${\mathrm{E}}_0$ values for the half reactions:

${\mathrm{Sn}}^{4+}+2{\mathrm{e}}^{-}\to {\mathrm{Sn}}^{2+},0.15\mathrm{V}$
$2{\mathrm{Hg}}^{2+}+2{\mathrm{e}}^{-}\to {\mathrm{Hg}}_2^{2+},0.92\mathrm{V}$
${\mathrm{PbO}}_2+4{\mathrm{H}}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{Pb}}^{2+}+2{\mathrm{H}}_2\mathrm{O},1.45\mathrm{V}$
Which of the following statements is true?