The electrolyte used in a mercury cell is:

Consider the figure and answer the following questions.
$(i)$ Cell $'A'$ has $E_{cell} = 2 \ V$ and cell $'B'$ has $E_{cell} = 1.1 \ V$. Which of the two cells,$'A'$ or $'B'$,will act as an electrolytic cell? Which electrode reactions will occur in this cell?
$(ii)$ If cell $'A'$ has $E_{cell} = 0.5 \ V$ and cell $'B'$ has $E_{cell} = 1.1 \ V$,then what will be the reaction at the anode and cathode?

$A$ variable,opposite external potential $(E_{ext})$ is applied to the cell $Zn | Zn^{2+} (1 \ M) || Cu^{2+} (1 \ M) | Cu$ of potential $1.1 \ V$. When $E_{ext} < 1.1 \ V$ and $E_{ext} > 1.1 \ V$,respectively,electrons flow from:

When a lead storage battery is charged,what happens?

$A$ fuel cell uses $CH_4$ gas and it forms $CO_3^{2-}$ at the anode. It is used to power a car with $96.5 \ A$ for $10000 \ s$. The volume of $CH_4$ gas required at $1 \ atm$ and $273 \ K$ is $............ \ L$.

When a piece of copper wire is dipped in $AgNO_3$ solution,the colour of the solution turns blue due to