The standard Gibbs energy change for the Daniel cell reaction is $Zn_{(s)} + Cu^{2+}_{(aq)} \longrightarrow Zn^{2+}_{(aq)} + Cu_{(s)}$ where $E_{\text{cell}}^{\circ} = 1.1 \ V$.

Given are $E^o$ values for some half reactions:
$I_2 + 2e^- \to 2I^{-}; E^o = 0.54 \ V$
$MnO_4^- + 8H^{+} + 5e^- \to Mn^{2+} + 4H_2O; E^o = 1.52 \ V$
$Fe^{3+} + e^- \to Fe^{2+}; E^o = 0.77 \ V$
$Sn^{4+} + 2e^- \to Sn^{2+}; E^o = 0.1 \ V$
The strongest reducant and oxidant respectively are:

Which one of the following metals cannot evolve $H_2$ from acids,$H_2O$,or from its compounds?

Given the standard electrode potentials: $Fe^{2+}_{(aq)} + 2e^{-} \rightarrow Fe_{(s)}$ $(E^o = -0.44 \ V)$ and $Fe^{3+}_{(aq)} + e^{-} \rightarrow Fe^{2+}_{(aq)}$ $(E^o = 0.77 \ V)$. If $Fe^{2+}$,$Fe^{3+}$,and a piece of $Fe$ are kept together,what happens?

The standard reduction potentials for two half-cell reactions are given below:
$Cd^{2+}_{(aq)} + 2e^{-} \rightarrow Cd_{(s)}, E^o = -0.40 \ V$
$Ag^{+}_{(aq)} + e^{-} \rightarrow Ag_{(s)}, E^o = 0.80 \ V$
What is the standard free energy change $\Delta G^o$ in $kJ$ for the reaction $2Ag^{+}_{(aq)} + Cd_{(s)} \rightarrow 2Ag_{(s)} + Cd^{2+}_{(aq)}$?

Bubbles of gas $z$ are evolved from a solution containing $x$ and $y$. If the order of reduction potential is $x > y > z$,then: