Question

Explain why powdered coke is sprinkled over the electrolyte mixture.

Answer 1

Coke is added to the electrolytic reduction of alumina as:

• Coke is added to the electrolytic mixture of the components to avoid the carbon rods from getting burnt during the electrolysis reaction.
• It also helps in reducing the heat loss due to the radiations from the molten electrolyte.
• It also combines with the oxygen gas being liberated to form carbon dioxide at the anode.

$$\begin{gathered} Reactionatanode:2O^{2-}\to O_2+4e^{-} \\ C+O_2\to C{O}_2 \end{gathered}$$