BITSAT 2018 Slot 2 Solved Paper

(i) In Hall-Heroult process for extraction of Al, carbon anode is oxidised to CO and CO2.
(ii) When Al2O3 is mixed with CaF2, it lowers the melting point of the mixture and brings conductivity.
(iii) Al3+ is reduced at cathode to form Al.
(iv) Al2O3 serves as the electrolyte, undergoing the redox process. Na3AlF6 although is an electrolyte but serves as a solvent, not electrolyte.