If $E^{\circ}_{Fe^{2+}/Fe} = -0.440 \ V$ and $E^{\circ}_{Fe^{3+}/Fe^{2+}} = 0.770 \ V$,then $E^{\circ}_{Fe^{3+}/Fe}$ is (in $V$)

The standard electrode potentials of two half-cells are given as: $Ni^{2+}_{(aq)} + 2e^{-} \rightarrow Ni_{(s)}$; $E^o = -0.25 \ V$ and $Zn^{2+}_{(aq)} + 2e^{-} \rightarrow Zn_{(s)}$; $E^o = -0.76 \ V$. What is the standard $emf$ of the cell formed by connecting these two half-cells in $volt$?

Which one among the following is the strongest reducing agent?
$Fe^{2+} + 2e^- \to Fe \ (E^\circ = -0.44 \ V)$
$Ni^{2+} + 2e^- \to Ni \ (E^\circ = -0.25 \ V)$
$Sn^{2+} + 2e^- \to Sn \ (E^\circ = -0.14 \ V)$
$Fe^{3+} + e^- \to Fe^{2+} \ (E^\circ = +0.77 \ V)$

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

Standard electrode potential of $SHE$ at $298 \, K$ is ............. $V$.

$A$ cell reaction is spontaneous when: