When does an electrochemical cell behave as an electrolytic cell?

Based on the reaction $\frac{4}{3} \, Al + O_2 \to \frac{2}{3} \, Al_2O_3$,with $\Delta G = -827 \, kJ \, mol^{-1}$ of $Al_2O_3$,what is the minimum $e.m.f.$ required for the electrolysis? $(F = 96500 \, C \, mol^{-1})$

Assertion : If $\lambda^o_{Na^{+}}$ and $\lambda^o_{Cl^{-}}$ are molar limiting conductivity of sodium and chloride ions respectively,then the limiting molar conductivity for sodium chloride is given by the equation :
$\Lambda^o_{NaCl} = \lambda^o_{Na^{+}} + \lambda^o_{Cl^{-}}$
Reason : This is according to Kohlrausch law of independent migration of ions.

Calculate $\Delta G^{\circ}$ for the following cell reaction.
$Zn_{(s)} + Ag_2O_{(s)} + H_2O_{(l)} \longrightarrow Zn^{2+}_{(aq)} + 2Ag_{(s)} + 2OH^{-}_{(aq)}$
Given: $E^{\circ}_{Ag^{+}/Ag} = +0.80 \ V$ and $E^{\circ}_{Zn^{2+}/Zn} = -0.76 \ V$

What is the reaction occurring at the anode in a $CH_4 - O_2$ fuel cell?

Which one of the following processes is non-spontaneous?