The e.m.f. of a cell whose half cells are given below is .............. $V$
$Mg^{2+} + 2e^- \to Mg_{(s)}$; $E^o = - 2.37 \ V$
$Cu^{2+} + 2e^- \to Cu_{(s)}$; $E^o = + 0.34 \ V$

Consider the systems having liquid-solid interface,$(A)$ copper wire in silver nitrate solution and $(B)$ silver wire in copper sulphate solution. Predict which interface will show spontaneous reaction,if $E_{Cu^{2+}/Cu}^{\circ} = 0.34 \ V$ and $E_{Ag^{+}/Ag}^{\circ} = 0.80 \ V$?

If the standard reduction potentials of four electrodes $A$, $B$, $C$, and $D$ are $+2.5 \text{ V}$, $+3.0 \text{ V}$, $-2.0 \text{ V}$, and $-1.5 \text{ V}$ respectively, in which of the following cases is the standard $emf$ of the cell maximum?

For the cell involving the following reaction: $Zn_{(s)} + Ni^{2+}_{(aq)} \longrightarrow Zn^{2+}_{(aq)} + Ni_{(s)}$. Given $E^{\circ}_{\text{cell}} = 0.5 \ V$. What is the standard Gibbs energy change of the cell reaction (in $kJ$)?

What is denoted by a negative $E^o$ and a positive $E^o$ value in electrochemistry?

What is the oxidation and reduction potential of standard hydrogen electrode?