What is the charge required for the reduction of two moles of $Cu^{2+}$ to $Cu$?

For how much time,$10 \ A$ electric current should be passed through a dilute aqueous $NiSO_4$ solution during electrolysis using inert electrode,in order to get $5.85 \ g$ Nickel (in $s$)?
[At. mass of $Ni = 58.5 \ g/mol$]

The amount of ion discharged during electrolysis is not directly proportional to

Electricity is passed through an acidic solution of $Cu^{2+}$ until all the $Cu^{2+}$ is exhausted, leading to the deposition of $300 \ mg$ of $Cu$ metal. Subsequently, a current of $600 \ mA$ is passed through the same solution for another $28 \ minutes$ while keeping the total volume of the solution fixed at $200 \ mL$. The total volume of oxygen evolved at $STP$ during the entire process is . . . . . . $mL$. (Nearest integer) [Given: $Cu^{2+}_{(aq)} + 2e^{-} \rightarrow Cu_{(s)}$, $E_{red}^0 = +0.34 \ V$; $O_{2(g)} + 4H^{+} + 4e^{-} \rightarrow 2H_2O$, $E_{red}^0 = +1.23 \ V$; Molar mass of $Cu = 63.54 \ g \ mol^{-1}$; Faraday Constant $= 96500 \ C \ mol^{-1}$; Molar volume at $STP = 22.4 \ L$]

The number of Faradays required to completely deposit magnesium from $1 \ L$ of $0.1 \ M$ $MgCl_2$ aqueous solution is

When electric current is passed through acidified water for $1930 \,s$, $1120 \,mL$ of $H_2$ gas is collected (at $STP$) at the cathode. What is the current passed in amperes?