Electrolysis Questions

4.5g of aluminium (at. mass 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be :

The mass of carbon anode consumed (giving only carbondioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is : (Atomic mass Al = 27)

${\text{Al}}_2{\text{O}}_3$ is reduced by electrolysis. If $4.0\times 10^4\text{amperes}$ of current is passed through molten ${\text{Al}}_2{\text{O}}_3$ for $6\text{hours}$, what mass of aluminium is produced? (At. mass of $\text{Al}=27{\text{g mol}}^{-1}$)