$2{\mathrm{Ce}}^{4+}+\mathrm{Co}⟶2{\mathrm{Ce}}^{3+}+{\mathrm{Co}}^{2+}$ ${\mathrm{E}}_{\mathrm{cell}}^{°}=1.89 \mathrm{V},$ ${\mathrm{E}}_{{\mathrm{co}}^{2+}/\mathrm{co}}^{°}=-0.277 \mathrm{V}$ hence, ${\mathrm{E}}_{{\mathrm{Ce}}^{4+}/{\mathrm{Ce}}^{3+}}^{°}$ is:

${\mathrm{MnO}}_4^{-}+8{\mathrm{H}}^{+}+5{\mathrm{e}}^{-}⟶{\mathrm{Mn}}^{2+}+4{\mathrm{H}}_2\mathrm{O};\mathrm{E}°=1.51 \mathrm{V} ; {\mathrm{\Delta G}}_1^0=-5\times 1.51\times \mathrm{F}$  ${\mathrm{MnO}}_2+4{\mathrm{H}}^{+}+2{\mathrm{e}}^{-}⟶{\mathrm{Mn}}^{2+}+2{\mathrm{H}}_2\mathrm{O} ; {\mathrm{E}}^{°}=1.23 \mathrm{V} ; \Delta {\mathrm{G}}_2^0=-2\times 1.23\times \mathrm{F}$ 

${\mathrm{E}}_{{\mathrm{MnO}}_4^{-}\mid {\mathrm{MnO}}_2}^{°}$ is:

Peroxodisulphate salts $\left({\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_8\right)$ are strong oxidizing agents used as bleaching agents for fats, oil etc. 
Given

$\begin{array}{ll}{\mathrm{O}}_2\left(\mathrm{g}\right)+4{\mathrm{H}}^{\oplus }\left(\mathrm{aq}\right)+4{\mathrm{e}}^{-}⟶2{\mathrm{H}}_2\mathrm{O}\left(\ell \right)& \mathrm{E}°=1.23\mathrm{V}\end{array}$

$\begin{array}{ll}{\mathrm{S}}_2{\mathrm{O}}_8^{-2}+2{\mathrm{e}}^{-}⟶2{\mathrm{SO}}_4^{-2}\left(\mathrm{aq}\right)& \mathrm{E}°=2.01\mathrm{V}\end{array}$

Which of the following statements is (are) correct?