Carbon plays a crucial role in the reduction of metal oxides as a strong reducing agent. In processes like smelting and thermal reduction, carbon, often in the form of coke or charcoal, reacts with metal oxides at high temperatures. The carbon undergoes oxidation, producing carbon dioxide (CO₂), while simultaneously reducing the metal oxide to its elemental metal form. The general reaction is:

MₓOᵧ + xC → xM + yCO₂
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This reaction exploits the carbon’s ability to donate electrons to metal cations, facilitating the reduction of metal oxides and the extraction of metals in metallurgical processes.