The standard potentials of the following half cells at 298 K are given

$$\begin{gathered} \begin{array}{l}{\mathrm{Mn}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Mn};\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}{\mathrm{E}}^0=-1.18\mathrm{V};\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}{\mathrm{Fe}}^{2+}+2\mathrm{e}\to \mathrm{Fe}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}{\mathrm{E}}^0=-0.44\mathrm{V}\end{array} \\ {\mathrm{Mn}}^{+3}+{\mathrm{e}}^{-}\to {\mathrm{Mn}}^{+2}; {\mathrm{E}}^0= -1.51\mathrm{V}; {\mathrm{Fe}}^{+3}+3{\mathrm{e}}^{-}\to \mathrm{Fe}; {\mathrm{E}}^0=-0.04\mathrm{V} \end{gathered}$$

Correct statements among the following is

(1) $\mathrm{\Delta }{G}^{\circ }\text{ of the reaction }{\mathrm{Fe}}^{3+}+3{\mathrm{e}}^{-}\to \mathrm{Fe} =-3\times \mathrm{F}\times -0.04=0.12\mathrm{F}$

(2) $\mathrm{\Delta }{G}^{\circ }\text{ of the reaction }{\mathrm{Fe}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Fe}=-2\times \mathrm{F}\times -0.44=0.88\mathrm{F}$

(a) $\text{ (1) - (2) gives }\mathrm{\Delta }{G}^{\circ }\text{ for the reaction }{\mathrm{Fe}}^{3+}+\mathrm{e}={\mathrm{Fe}}^{2+}\text{ as }-0.76\mathrm{F}$

$\text{ or }\begin{array}{r}-nF{E}^{\circ }=-0.76\mathrm{F}\\ E^{\circ }=\frac{0.76\mathrm{F}}{1\times \mathrm{F}}=0.76\mathrm{V}\end{array}$

(b) (1) $\mathrm{\Delta }{G}^{\circ }\text{ for the reaction }{\mathrm{Mn}}^{3+}+{\mathrm{e}}^{-}\to {\mathrm{Mn}}^{2+}=-\mathrm{F}\times 1.51=-1.51\mathrm{F}$

(2) $\mathrm{\Delta }{G}^{\circ }\text{ for the reaction }{\mathrm{Mn}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Mn}=-2\mathrm{F}\times -1.18=2.36\mathrm{F}$

(1) + (2) $\text{ gives }\mathrm{\Delta }{G}^{\circ }\text{ for the reaction }{\mathrm{Mn}}^{3+}+3{\mathrm{e}}^{-}\to \mathrm{Mn}\text{ as }0.85\mathrm{F}\text{. }$

$\text{ or }-nF{E}^{\circ }=-3\cancel{F}{E}^{\circ }=0.85\cancel{F}$

or $E^{\circ }=-\frac{0.85}{3}=-0.283\mathrm{V}$

(3) $\text{ For the reaction }{\mathrm{Mn}}^{3+}+3{\mathrm{Fe}}^{2+}⟶\mathrm{Mn}+3{\mathrm{Fe}}^{3+}$

$E^{\circ }\text{ of the reaction }={E^{\circ }}_{{\mathrm{Mn}}^{3+},\mathrm{Mn}}- E_{{\mathrm{Fe}}^{3+},{\mathrm{Fe}}^{2+}}^{\circ }$

$=-0.283-0.760=-1.043\mathrm{V}$

(4) The reaction  (3) is not feasible because E_cell is negative