Under what condition is $E_{cell} = 0$ or $\Delta_r G = 0$?

Write a note on mercury cell $(Zn-Hg)$.

Which of the following will not displace hydrogen from dilute acids?

Identify the anode,cathode,positive electrode,and negative electrode for the $Daniell$ cell $(Zn-Cu)$ and the $Copper-Silver$ $(Cu-Ag)$ cell.

Calculate $\Delta_r G^o$ for the cell reaction:
$Zn_{(s)} + Cu^{2+}_{(aq)} \to Zn^{2+}_{(aq)} + Cu_{(s)}$
Given: $E^o_{Cu^{2+}/Cu} = 0.34 \, V, E^o_{Zn^{2+}/Zn} = -0.76 \, V$

Consider the following diagram in which an electrochemical cell is coupled to an electrolytic cell. What will be the polarity of electrodes $A$ and $B$ in the electrolytic cell?