How much current in amperes should be passed through a $Na_2SO_4$ solution using graphite electrodes to obtain $250 \ mL$ of $O_2$ gas per minute at $1 \ bar$ pressure and $300 \ K$ temperature (in $A$)? $[R = 0.08314 \ L \ bar \ K^{-1} \ mol^{-1}]$

The approximate time duration in hours to electroplate $30 \ g$ of calcium from molten calcium chloride using a current of $5 \ A$ is [At. mass of $Ca=40$]

Aqueous $CuSO_4$ solution was electrolysed by passing $2 \ A$ of current for $10 \ min$. What is the weight (in $g$) of copper deposited at the cathode? (Given: $Cu = 63 \ u$; $F = 96500 \ C \ mol^{-1}$)

Electrolytic cells containing $Zn$ and $Al$ salt solutions are connected in series. If $6.5 \ g$ of $Zn$ is deposited in one cell,calculate the mass of $Al$ deposited in the second cell (molar mass: $Zn=65 \ g \ mol^{-1}$,$Al=27 \ g \ mol^{-1}$) by passing a definite quantity of electricity. (in $g$)

How much electricity in terms of Faraday is required to produce:
$(i)$ $20.0 \, g$ of $Ca$ from molten $CaCl_2$?
$(ii)$ $40.0 \, g$ of $Al$ from molten $Al_2O_3$?

Same amount of electricity is passed through aqueous solutions of $AgNO_3$ and $CuSO_4$. The number of $Ag$ and $Cu$ atoms deposited are $x$ and $y$ respectively. The correct relationship between $x$ and $y$ is