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

$MX$ is a sparingly soluble salt that follows the given solubility equilibrium at $298 \ K$: $MX_{(s)} \rightleftharpoons M^{+}_{(aq)} + X^{-}_{(aq)}$; $K_{sp} = 10^{-10}$. If the standard reduction potential for $M^{+}_{(aq)} + e^- \rightarrow M_{(s)}$ is $(E^{\ominus}_{M^{+}/M}) = 0.79 \ V$, then the value of the standard reduction potential for the metal/metal insoluble salt electrode $E^{\ominus}_{X^{-}/MX_{(s)}/M}$ is . . . . . . $mV$. (nearest integer) [Given: $\frac{2.303 RT}{F} = 0.059 \ V$]

Which of the following metals does not liberate hydrogen from dilute hydrochloric acid?

The values of $E^0$ for metals $A$,$B$,and $C$ are $0.34 \ V$,$-0.80 \ V$,and $-0.46 \ V$ respectively. State the correct order for their ability to act as reducing agents.

Aluminium displaces hydrogen from dilute $HCl$ whereas silver does not. The e.m.f. of a cell prepared by combining $Al/Al^{3+}$ and $Ag/Ag^{+}$ is $2.46 \ V$. The reduction potential of silver electrode is $+0.80 \ V$. The reduction potential of aluminium electrode is $........... \ V$.

$A$ solution contains $Fe^{2+}$,$Fe^{3+}$ and $I^{-}$ ions. This solution was treated with iodine at $35^{\circ}C$. $E^{\circ}$ for $Fe^{3+}/Fe^{2+}$ is $+0.77 \ V$ and $E^{\circ}$ for $I_2/2I^{-}$ is $+0.536 \ V$. The favourable redox reaction is