To prove that carbon can be both a reducing agent and an oxidizing agent?

Under normal conditions, carbon is chemically inert (inactive). Under strong heating (above 300 ° C for amorphous carbon) carbon exhibits reducing properties, oxidizing to compounds containing carbon in the oxidation state from +1 to +4.

C + H2O = CO + H2

FeO + C = Fe + CO

C + 2S = CS2

However, when interacting with stronger reducing agents (for example, metals) when heated, carbon behaves as an oxidizing agent, reducing to carbon in the oxidation state -4.

2Be + C = Be2C

4Al + 3C = Al4C3