An electric current is passed through a silver voltameter connected to a water voltameter. The cathode of the silver voltameter weighed $0.108 \ g$ more at the end of the electrolysis. The volume of oxygen evolved at $STP$ is ............... $cm^{3}$.

Two electrolytic cells containing molten solutions of nickel chloride and aluminium chloride are connected in series. If the same amount of electric current is passed through them,what will be the weight of nickel obtained when $18 \ g$ of aluminium is obtained (in $g$)? $[Al = 27 \ g/mol, Ni = 58.5 \ g/mol]$

In a copper voltameter experiment,current is decreased to one-fourth of the initial value but it is passed for four times the earlier duration. The amount of copper deposited will be:

In an electroplating experiment,$m \ g$ of silver is deposited when $4 \ A$ of current flows for $2 \ min$. The amount (in $g$) of silver deposited by $6 \ A$ of current flowing for $40 \ s$ will be:

How much electricity is required in coulomb for the oxidation of
$(i)$ $1 \, mol$ of $H_2O$ to $O_2?$
$(ii)$ $1 \, mol$ of $FeO$ to $Fe_2O_3?$

$Al_2O_3$ is reduced by electrolysis at low potentials and high currents. If $4.0 \times 10^4$ amperes of current is passed through molten $Al_2O_3$ for $6$ hours,what mass of aluminium is produced? (Assume $100\%$ current efficiency,at. mass of $Al = 27 \ g \ mol^{-1}$).