Chemistry - Metallurgy Question with Solution | TestHub

In Serpeck's process, carbon acts as a reducing agent, so statement (A) is incorrect.

In the Hall–Heroult process, both CO and CO₂ are formed at the carbon anode, not only CO₂. Hence, (B) is incorrect.

In the Hoopes process, CaF₂ is not added to increase conductivity; it is part of the molten electrolyte composition. Hence, (C) is incorrect.

In the Hall–Heroult process, cryolite (Na₃AlF₆) and fluorspar (CaF₂) are added to increase the conductivity and lower the melting point of the electrolyte. Hence, (D) is correct.

Correct Answer: (A), (B) and (C)