Exams › JEE Main › Chemistry

In the context of the Hall - Heroult process for the extraction of Al, which of the following statement is false? (1) CO and CO2 are produced in this process (2) Al2O3 is mixed with CaF2 which lowers the melting point of the mixture and brings conductivity (3) Al3+ is reduced at the cathode to form Al (4) Na3AlF6 serves as the electrolyte

1. CO and CO2 are produced in this process
2. Al2O3 is mixed with CaF2 which lowers the melting point of the mixture and brings conductivity
3. Al3+ is reduced at the cathode to form Al
4. Na3AlF6 serves as the electrolyte

Correct answer: Na3AlF6 serves as the electrolyte

Solution

Na3AlF6, also known as cryolite, is indeed used as an electrolyte in the Hall-Heroult process, making this statement true. The other options correctly describe aspects of the process, while this one is misleading as it implies a falsehood about the role of cryolite.

Related JEE Main Chemistry questions

• Thomas slag refers to which of the following substances?
• Which of the following fluxes is employed to eliminate acidic impurities during a metallurgical operation?
• Which material is used to provide a basic lining to a furnace?
• Electromagnetic separation is employed in the beneficiation of which ore?
• In the cyanide leaching process used for obtaining gold and silver, the metal is subsequently recovered by which method?
• Which of the following chemical changes best represents calcination?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →