If $E^0_{Fe^{2+} / Fe} = -0.441 \ V$ and $E^0_{Fe^{3+} / Fe^{2+}} = 0.771 \ V$,the standard emf of the cell reaction $Fe_{(s)} + 2 Fe^{3+}_{(aq)} \longrightarrow 3 Fe^{2+}_{(aq)}$ is

Which among the following species is reduced by tin easily?

For the cell reaction,$2Ce^{4+} + Co \to 2Ce^{3+} + Co^{2+}$,$E_{cell}^o$ is $1.89 \, V$ and $E_{Co/Co^{2+}}^o = +0.28 \, V$. If $E_{Ce^{4+}/Ce^{3+}}^o = x$,then $x$ is ............. $V$.

If in a galvanic cell,the hydrogen half-cell is the cathode on the right side,what is the sign of the standard electrode potential of such a galvanic cell? Give an example.

Which of the following transformations can be carried out by using $HI$ as a reducing agent,under acidic conditions?
[Given: $I_{2(s)} \rightarrow 2I^- ; E^{\circ} = 0.54 \ V$]
$(i)$ $Cu^+ \rightarrow Cu_{(s)} ; E^{\circ} = 0.52 \ V$
$(ii)$ $Cr^{3+} \rightarrow Cr^{2+} ; E^{\circ} = -0.41 \ V$
$(iii)$ $Fe^{3+} \rightarrow Fe^{2+} ; E^{\circ} = 0.77 \ V$
$(iv)$ $Fe^{2+} \rightarrow Fe_{(s)} ; E^{\circ} = -0.44 \ V$

Consider the following reduction processes:
$Al^{3+} + 3e^{-} \rightarrow Al_{(s)}, E^{\circ} = -1.66 \ V$
$Fe^{3+} + e^{-} \rightarrow Fe^{2+}, E^{\circ} = +0.77 \ V$
$Co^{3+} + e^{-} \rightarrow Co^{2+}, E^{\circ} = +1.81 \ V$
$Cr^{3+} + 3e^{-} \rightarrow Cr_{(s)}, E^{\circ} = -0.74 \ V$
The tendency to act as a reducing agent decreases in the order: