In the metallurgy of aluminium

Options

A. `Al^(3+)` is oxidised to Al(s).
B. graphite anode is oxidised to carbon monoxide and carbon dioxide.
C. oxidation state of oxygen changes in the reaction at anode.
D. oxidation state of oxygen changes in the overall reaction involved in the process.

Answer

B

Explanation

In the metallurgy of `Al, Al^(3+)` is reduced to Al and there is no change in oxidation number of O in the reaction taking place at anode or during the overall reaction as shown below:
` C + O_^(2-) to C^(2+) O^(2-) + 2e^(-) , " " C + 2O^(2-) to C^(4+) (O^(2-))_2`
` Al_2^(3+) O_3^(2-) + 3C to 2Al + 3C^(2+) + O^(2-)`