How many seconds of current at $9.65 \ A$ must be passed through a solution of $Al^{3+}$ to obtain $1 \ \text{millimole}$ of $Al$ metal?

Two electrolytic cells containing $CuSO_4$ and $AgNO_3$ respectively are connected in series and a current is passed through them until $1 \, mg$ of copper is deposited in the first cell. The amount of silver deposited in the second cell during this time is approximately ......... $mg$ [Atomic weights of copper and silver are respectively $63.57$ and $107.88$]

When $0.04$ faraday of electricity is passed through a solution of $CaSO_4$,then the weight of $Ca^{2+}$ metal deposited at the cathode is $.............$ $g$.

When an electric current is passed through acidulated water,$112 \ mL$ of hydrogen gas at $N.T.P.$ collects at the cathode in $965 \ seconds$. The current passed,in amperes,is:

Faraday's laws of electrolysis will fail when

$4.5 \ g$ of aluminium (atomic mass $27 \ amu$) is deposited at the cathode from an $Al^{3+}$ solution by a certain quantity of electric charge. The volume of hydrogen produced at $STP$ from $H^{+}$ ions in the solution by the same quantity of electric charge will be .............. $L$.