When a current of $2 \ A$ is passed for $2 \ hours$ through a copper voltameter,$W \ g$ of copper is deposited. If a current of $1 \ A$ is passed for $4 \ hours$ through the same voltameter,how much copper will be deposited?

Aluminium oxide may be electrolysed at $1000 \, ^\circ C$ to furnish aluminium metal (At. Mass $= 27 \, amu$; $1 \, F = 96,500 \, C$). The cathode reaction is $Al^{3+} + 3e^- \to Al^0$. To prepare $5.12 \, kg$ of aluminium metal by this method would require:

Electrolysis of $600 \ mL$ aqueous solution of $NaCl$ for $5 \ min$ changes the $pH$ of the solution to $12$. The current in Amperes used for the given electrolysis is $...........$. $(Nearest \ integer)$.

The number of Faradays $F$ required to produce $20 \ g$ of calcium from molten $CaCl_2$ (Atomic mass of $Ca = 40 \ g \ mol^{-1}$) is

$96500 \ C$ of electric charge liberates how many grams of $Cu$ from $CuSO_4$ solution?

$6.5 \, g$ 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 $STP$?