What is achieved by Faraday using the principles of electrolysis?

When an electric current is passed through a solution of $KCl$,$19.5 \ g$ of potassium (atomic mass $= 39$) is deposited. If the same amount of electric current is passed through a solution of $AlCl_3$,how many grams of aluminum will be liberated?

How long a current of $3 \, A$ has to be passed through a solution of $AgNO_3$ to coat a metal surface of $80 \, cm^2$ with $0.005 \, mm$ thick layer? Density of $Ag$ is $10.5 \, g/cm^3$. (Answer in $sec$)

When a current of $0.5 \ A$ is passed for $2 \ hours$ through a molten metal salt,$3.88 \ g$ of the metal was deposited. If the atomic mass of the metal is $208 \ units$,the oxidation state of the metal in the salt is:

$A$ solution of copper sulphate $(CuSO_4)$ is electrolysed for $10 \, \text{minutes}$ with a current of $1.5 \, \text{amperes}$. The mass of copper deposited at the cathode (atomic mass of $Cu = 63 \, u$) is ............ $g$.

Cells $A$ and $B$ contain aqueous solutions of ferrous chloride $(FeCl_2)$ and ferric chloride $(FeCl_3)$ respectively. If the same quantity of electricity is passed through both cells, what is the ratio of the mass of iron deposited in cell $A$ to that in cell $B$?