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

Question

In the context of the Hall-Heroult process for the extraction of textAl, which of the following statements is false ? (A) CO and C O2 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) Na3AlF6 helps in increasing the melting point of the mixture

Tardigrade Admin · Accepted Answer

Hall heroult process:

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

Cathode:

A l^{3 +} + 3 e^{- 1} \to A l

Anode:

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

Overall:

A l_{2} O_{3} + 3 C \to 2 A l + 3 CO

And

2 A l_{2} O_{3} + 3 C \to 4 A l + 3 C O_{2}

In reality, much more

C O_{2}

is formed at the anode than

CO :

Cryolite (

N a_{3} A l 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.

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

CO and $C O_{2}$ are produced in this process

$A l_{2} O_{3}$ is mixed with $C a F_{2}$ which lowers the melting point of the mixture and brings conductivity

$A l^{3 +}$ is reduced at the cathode to form Al

$N a_{3} A l F_{6}$ helps in increasing the melting point of the mixture

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

CO and CO2​ are produced in this process

Al2​O3​ is mixed with CaF2​ which lowers the melting point of the mixture and brings conductivity

Al3+ is reduced at the cathode to form Al

Na3​AlF6​ helps in increasing the melting point of the mixture

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

CO and $C O_{2}$ are produced in this process

$A l_{2} O_{3}$ is mixed with $C a F_{2}$ which lowers the melting point of the mixture and brings conductivity

$A l^{3 +}$ is reduced at the cathode to form Al

$N a_{3} A l F_{6}$ helps in increasing the melting point of the mixture