Reactions in Blast Furnace Iron Extraction

Steps:

• Combustion occurs when coke (C) reacts with oxygen: C + O₂ → CO₂, providing heat and CO.
• Redox reaction reduces iron oxide: Fe₂O₃ + 3CO → 2Fe + 3CO₂, where Fe³⁺ gains electrons.
• Acid-base reaction forms slag: CaO (base from limestone) + SiO₂ (acidic oxide) → CaSiO₃, neutralizing impurities.
• All three types are essential for the process.

Why A is correct:

• Blast furnace involves combustion for energy, redox for iron reduction (per electron transfer definition), and acid-base for slag (per neutralization of oxides).

Why the others are wrong:

• B omits redox, but iron extraction requires oxide reduction.
• C omits combustion, but coke burning supplies necessary heat and reducing agent.
• D omits acid-base, but slag formation neutralizes silica impurities.

Final answer: A