$E^o$ values of $Mg^{2+}/Mg$,$Zn^{2+}/Zn$ and $Fe^{2+}/Fe$ are $-2.37 \ V$,$-0.76 \ V$ and $-0.44 \ V$ respectively. Which of the following statements is correct?

Given $E_{Fe^{+3}/Fe}^{\circ} = -0.036 \ V$ and $E_{Fe^{+2}/Fe}^{\circ} = -0.439 \ V$,calculate the standard electrode potential for the reaction: $Fe^{+3}_{(aq)} + e^{-} \rightarrow Fe^{+2}_{(aq)}$ (in $V$)

What does the negative sign in the expression $E_{Zn^{2+}|Zn}^o = -0.76 \ V$ mean?

Assertion : Copper reacts with $HCl$ and liberates hydrogen.
Reason : Hydrogen is present above $Cu$ in the reactivity series.

If the $emf$ of the cell $Cu(s) | Cu^{2+}(1 \text{ M}) || Ag^+(1 \text{ M}) | Ag(s)$ is $0.463 \text{ V}$ at $25^{\circ} \text{C}$ and the standard electrode potential of the $Cu$ electrode is $0.337 \text{ V}$, find the standard electrode potential of the $Ag$ electrode. (in $\text{ V}$)

Given $E^{\circ} Mn^{7+} / Mn^{2+} = 1.51 \ V$ and $E^{\circ} Mn^{4+} / Mn^{2+} = 1.23 \ V$. Calculate $E^{\circ} Mn^{7+} / Mn^{4+}$. (in $V$)