For the given reaction how much quantity of electricity in Coulomb is required? $\frac{2}{3} Al_2O_3 \rightarrow \frac{4}{3} Al + O_2$

The quantity of electricity required to deposit $1$ gram-equivalent of a substance at an electrode is equal 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 $STP = 22.4 \ L$]

Two electrolytic cells,one containing acidified ferrous chloride $(FeCl_2)$ and the other containing acidic ferric chloride $(FeCl_3)$,are connected in series. When an electric current is passed through the cells,what is the ratio of iron deposited at the cathodes in the two cells?

The quantity of electricity required to liberate $5600 \ mL$ of $H_2$ at $STP$ is the same as that required to liberate how many grams of silver (equivalent weight = $108$)?

$A$ current of $0.01 \ A$ is passed through a solution of a metal bromide $(MBr_x)$. The only reaction at the cathode is the deposition of metal $(M)$. After $3 \ hours$,$0.072 \ g$ of metal $(M)$ is deposited. The value of '$x$' is approximately (Given: Atomic weight of $M = 192$)