Discussion Forum



1)

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


A) Co and $CO_{2}$ are produced in the process.

B) $Al_{2}O_{3}$ is mixed with $CaF_{2}$ which lowers the melting point of the mixture and brings conductivity.

C) $Al^{3+}$ is reduced at the cathode to form Al

D) $Na_{3}AlF_{6}$ serves as the electrolyte

Answer:

Option D

Explanation:

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

(b) When Al2 O3 is mixed with CaF2. It lowers the melting  point of the mixture  and brings conductivity

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

(d) Here, Al2O3   is an electrolyte, undergoing the redox process, Na3 AlF6   although is an electrolyte but serves as a solvent. not electrolyte.