If $Cu^{+} + e^- \to Cu$ ; $E^o = X_1$ and $Cu^{2+} + 2e^- \to Cu$ ; $E^o = X_2$,then the value of $E^o$ for $Cu^{2+} + e^- \to Cu^{+}$ will be:

Among $Mg$,$Cu$,$Fe$,and $Zn$,the metal that does not produce hydrogen gas in reaction with hydrochloric acid is:

Four metals $A$,$B$,$C$,and $D$ have Standard Reduction Potential $(SRP)$ values of $-3.05 \ V$,$-1.66 \ V$,$-0.40 \ V$,and $0.80 \ V$ respectively. Which is the strongest reducing agent?

Given the standard electrode potentials: $E^o_{Cr^{3+}/Cr} = -0.74 \ V$,$E^o_{MnO_4^-/Mn^{2+}} = 1.51 \ V$,$E^o_{Cr_2O_7^{2-}/Cr^{3+}} = 1.33 \ V$,and $E^o_{Cl_2/Cl^-} = 1.36 \ V$. Based on this information,which is the strongest oxidizing agent?

$Mg^{2+}$ displaces hydrogen from acids but copper does not. $A$ galvanic cell prepared by combining $Cu/Cu^{2+}$ and $Mg/Mg^{2+}$ has an $EMF$ of $2.71 \ V$ at $298 \ K$. If the potential of copper electrode is $0.34 \ V$,what is the reduction potential of $Mg$ electrode?

Standard reduction potentials for the following reactions are :
$Fe^{3+} + 3e^{-} \rightarrow Fe ; E^{\circ}_{1} = -0.036 \ V$
$Fe^{2+} + 2e^{-} \rightarrow Fe ; E^{\circ}_{2} = -0.44 \ V$
What will be the standard electrode potential for
$Fe^{3+} + e^{-} \rightarrow Fe^{2+} (in $V$)?$