Reduction of haematite by carbon monoxide in iron extraction

Steps:

• Identify haematite as Fe₂O₃, the iron ore used in the blast furnace.
• Recall that coke burns to produce CO, which acts as the reducing agent.
• Note the key reaction: Fe₂O₃ + 3CO → 2Fe + 3CO₂, yielding molten iron.
• Confirm other processes like slag formation support but do not directly obtain iron.

Why C is correct:

• Haematite (Fe₂O₃) is reduced to iron by carbon monoxide via the reaction Fe₂O₃ + 3CO → 2Fe + 3CO₂, the primary step in iron production.

Why the others are wrong:

• A: Calcium carbonate forms slag to remove impurities like silica, but this is a supporting process, not the direct extraction of iron.
• B: Haematite is reduced, not oxidised; CO₂ can react but does not oxidise Fe₂O₃.
• D: Haematite does not decompose thermally to yield iron; it requires reduction.

Final answer: C