Which substance is used as an oxidising agent in a nickel-cadmium cell?

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

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?

An electrochemical cell is set up as follows: $Pt(H_2, 1 \, atm) | 0.1 \, M \, HCl || 0.1 \, M \, CH_3COOH | (H_2, 1 \, atm) Pt$. The $E.M.F.$ of this cell will not be zero because:

What happens during the discharge of a lead storage battery?

Standard electrode potentials for a few half cells are mentioned below:
$E^0_{Cu^{2+}/Cu} = 0.34 \ V, E^0_{Zn^{2+}/Zn} = -0.76 \ V$
$E^0_{Ag^{+}/Ag} = 0.80 \ V, E^0_{Mg^{2+}/Mg} = -2.37 \ V$
Which one of the following cells gives the most negative value of $\Delta G^0$?