How much electricity in terms of Faraday is required to produce $2.7 \ g$ of $Al$ from molten $Al_2O_3$? (Atomic mass of $Al = 27 \ u$)

How many grams of cobalt metal will be deposited when a solution of cobalt $(II)$ chloride is electrolyzed with a current of $10 \ A$ for $109$ minutes? ($1 \ Faraday = 96,500 \ C$; Atomic mass of $Co = 59 \ u$)

How many faraday are needed to reduce a mole of $MnO_4^-$ to $Mn^{2+}$?

The ratio of weights of hydrogen gas liberated and magnesium deposited by passing the same amount of electricity from aqueous $H_2SO_4$ and fused $MgSO_4$ are :

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

When a copper voltameter is connected with a battery of $e.m.f.$ $12 \ V$,$2 \ g$ of copper is deposited in $30 \ minutes$. If the same voltameter is connected across a $6 \ V$ battery,then the mass of copper deposited in $45 \ minutes$ would be ............. $g$.