The cell potential of a cell in operation is

Addition of powdered lead and iron to a solution which is $1.0 \, M$ in both $Pb^{2+}$ and $Fe^{2+}$ would result in [$E^{\circ}_{Fe^{2+}/Fe} = -0.44 \, V$ and $E^{\circ}_{Pb^{2+}/Pb} = -0.13 \, V$]

Which among the following reactions will take place spontaneously?

What is the standard reduction potential $(E^o)$ for $Fe^{3+} \to Fe$ ? ............... $V$
Given that :
$Fe^{2+} + 2e^- \to Fe;$ $E^o_{Fe^{2+}/Fe} = -0.47 \ V$
$Fe^{3+} + e^- \to Fe^{2+};$ $E^o_{Fe^{3+}/Fe^{2+}} = +0.77 \ V$

Consider the following ${E^0}$ values:
${E^0}_{Fe^{3+}/Fe^{2+}} = + 0.77 \ V$
${E^0}_{Sn^{2+}/Sn} = - 0.14 \ V$
Under standard conditions,the potential for the reaction $Sn_{(s)} + 2Fe^{3+}_{(aq)} \to 2Fe^{2+}_{(aq)} + Sn^{2+}_{(aq)}$ is ............ $V$.

Given standard electrode potentials:
$Fe^{2+} + 2e^- \to Fe; E^o = -0.440 \ V$
$Fe^{3+} + 3e^- \to Fe; E^o = -0.036 \ V$
The standard electrode potential $(E^o)$ for $Fe^{3+} + e^- \to Fe^{2+}$ is .............. $V$.