Question

In the context of the Hall-Heroult process for the extraction of Al, which of the following statements is false?

(a) CO and CO₂, are produced in this process

(b)Al₂O₃ is mixed with CaF₂, which lowers the melting point of the mixture and brings conductivity

(c) Al³⁺ is reduced at the cathode to form Al

(d) Na₃AIF₆ serves as the electrolyte

Answer 1

Correct option (d) Na₃AIF₆ serves as the electrolyte

Explanation:

(a) In Hall-Herouit process for extraction of Al, carbon anode is oxidised to CO and CO₂  

(b) When Al is mixed with CaF₂, it lowers the melting point of the mixture brings conductivity.

(c) Al³⁺ is reduced at cathode to form Al.

(d) Here, Al₂O₃ is an electrolyte, undergoing the redox process. Na₃AlF₆ although is an electrolyte but serves as a solvent, not electrolyte.