When a copper voltameter is connected with a battery of $e.m.f.$ $12 \ V$,$2 \ g$ of copper is deposited in $30 \ minutes$. If the same voltameter is connected across a $6 \ V$ battery,then the mass of copper deposited in $45 \ minutes$ would be ............. $g$.

What is the quantity of electricity (in Coulombs) required to deposit all the silver from $250 \text{ mL}$ of $1 \text{ M AgNO}_3$ solution?

$A$ current of $15.0 \ A$ is passed through a solution of $CrCl_2$ for $45 \ min$. The volume of $Cl_2$ (in $L$) obtained at the anode at $1 \ atm$ and $273 \ K$ is around ($1 \ F = 96500 \ C \ mol^{-1}$,At. wt. of $Cl=35.5$,$R=0.082 \ L \ atm \ K^{-1} \ mol^{-1}$) (in $.7$)

$6.5 \, g$ of $Mg$ is deposited during the electrolysis of fused $MgCl_2$. What will be the volume of chlorine gas (in $L$) discharged at the electrode at $STP$?

In the Hall process,aluminium is produced by the electrolysis of molten $Al_2O_3$. How many seconds would it take to produce enough aluminium by the Hall process to make a case of $24$ cans of aluminium soft-drink,if each can uses $5.0 \ g$ of $Al$,a current of $9650 \ A$ is employed,and the current efficiency of the cell is $90.0 \ \%$?

When two electrolytic cells containing $NiSO_4$ and $CuSO_4$ solutions are connected in series and an electric current is passed,$1.6 \ g$ of $Cu$ is deposited on the electrode. How much $Ni$ metal is produced? If a cell containing $AgNO_3$ solution is connected instead of $NiSO_4$,how many grams of silver will be obtained? [Atomic mass: $Cu = 63.5 \ g/mol$,$Ni = 58.7 \ g/mol$,$Ag = 108 \ g/mol$]