Which among the following equations represents the reduction taking place in a lead accumulator at the positive electrode,while it is being used as a source of electrical energy?

$A$ solution containing $1 \ mol \ L^{-1}$ of each $Cu(NO_3)_2, AgNO_3, Hg_2(NO_3)_2$ and $Mg(NO_3)_2$ is being electrolysed using inert electrodes. The standard reduction potentials are $E^0_{Ag^{+}/Ag} = +0.80 \ V, E^0_{Hg_2^{2+}/Hg} = +0.79 \ V, E^0_{Cu^{2+}/Cu} = +0.34 \ V, E^0_{Mg^{2+}/Mg} = -2.37 \ V$. With increasing voltage,the sequence of deposition of metals on the cathode will be:

At $25^{\circ} C$,the molar conductance at infinite dilution for the strong electrolytes $NaOH$,$NaCl$ and $BaCl_{2}$ are $248 \times 10^{-4}$,$126 \times 10^{-4}$ and $280 \times 10^{-4} \ S \ m^{2} \ mol^{-1}$ respectively. $\lambda_{m}^{o} Ba(OH)_{2}$ in $S \ m^{2} \ mol^{-1}$ is

What happens during the discharge of a lead storage battery?

In $H_2-O_2$ fuel cell,the reaction occurring at the cathode is:

Which of the following curves represents the variation of $\lambda_{M}$ with $\sqrt{C}$ for $AgNO_{3}$?