For the following cell,the standard electrode potential $E_{cell}^0$ is . . . . . . .
$E_{Zn^{2+}/Zn}^0 = -0.76 \ V, E_{Cu^{2+}/Cu}^0 = 0.34 \ V$
$Zn | Zn^{2+} || Cu^{2+} | Cu$ (in $V$)

The standard oxidation potentials of zinc and silver in water at $298 \ K$ are:
$Zn_{(s)} \to Zn^{2+}_{(aq)} + 2e^- ; E^o_{ox} = 0.76 \ V$
$Ag_{(s)} \to Ag^{+}_{(aq)} + e^- ; E^o_{ox} = -0.80 \ V$
Which of the following reactions actually takes place spontaneously?

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 case is the standard $emf$ of the cell maximum?

What is the observation we get when a gold ring is placed in the solution of $AgNO_3$? $[E_{Ag^{+}|Ag}^o = 0.80 \ V$ and $E_{Au^{3+}|Au}^o = 1.40 \ V]$

Which of the following is the strongest reducing agent?

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