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

Question

Quantrex Academy · Accepted Answer

Correct answer: D. N a _ 3 Al F _ 6 helps in increasing the melting point of the mixture

Hall heroult process:
In the Hall-Héroult process the following simplified reactions take place at the carbon electrodes:
Cathode:

Al^{3 +} + 3e^{- 1} \to Al

Anode:

O^{2 -} + C \to CO + 2e^{-}

Overall:
A{l}_{2}{O}_{3} + 3C \to 2Al + 3CO

<br />And 2A{l}_{2}{O}_{3} + 3C \to 4Al + 3C{O}_{2}

In reality, much more

C{O}_{2}

is formed at the anode than

CO:

Cryolite (N{a}_{3}Al{F}_{6}

) lowers the melting point of the mixture and make it more conductive in nature so as to carry out electrolysis of the ore in Hall-Heroult process.

In the context of the Hall-Heroult process for the extraction of...