Standard electrode potential data are useful for understanding the suitability of an oxidant in a redox titration. Some half cellreactions and their standard potentials are given below: 
$$\begin{gathered} \left.{\mathrm{MnO}}_4^{-}\text{(aq.) }+8{\mathrm{H}}^{+}\text{(aq. }\right)+5{\mathrm{e}}^{-}\to {\mathrm{Mn}}^{2+}\text{ (aq.) }+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right),{\mathrm{E}}^{\mathrm{o}}=1.51\mathrm{V} \\ \begin{array}{r}{\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}\text{ (aq.) }+14{\mathrm{H}}^{+}(\mathrm{aq}.)+6{\mathrm{e}}^{-}\to 2{\mathrm{Cr}}^{3+}(\mathrm{aq}.)+7{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\\ {\mathrm{E}}^{\circ }=1.38\mathrm{V}\end{array} \\ {\mathrm{Fe}}^{3+}(\mathrm{aq}.)+{\mathrm{e}}^{-}\to {\mathrm{Fe}}^{2+}(\mathrm{aq}.){\mathrm{E}}^{\circ }=0.77\mathrm{V} \\ {\mathrm{Cl}}_2\left(\mathrm{g}\right)+2{\mathrm{e}}^{-}\to 2{\mathrm{Cl}}^{-}\text{(aq.) }{\mathrm{E}}^{\circ }=1.40\mathrm{V} \end{gathered}$$
Identify the only incorrect statement regarding the quantitative estimation of aqueous $\mathrm{Fe}{\left({\mathrm{NO}}_3\right)}_2$