Chemistry · Electrolytic and metallic conduction, conductance in electrolytic solutions, molar conductivities and their variation with concentration, Kohlrausch's law and its applications

The role of coke in the electrolytic reduction of alumina is to

The role of coke in the electrolytic reduction of alumina is to

  • A. provide heat for melting of alumina
  • B. prevent loss of heat
  • C. prevent burning of carbon rods
  • D. reduce alumina to metal

Step-by-step solution

In the electrolytic reduction of alumina (Hall-Héroult process), carbon from coke serves as the anode material. During electrolysis, oxygen ions react with carbon to form CO₂, effectively removing oxygen. The overall net reaction is 2Al₂O₃ + 3C → 4Al + 3CO₂, so carbon acts as the reducing agent, chemically reducing alumina to aluminum metal.
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