Iron ore haematite (also spelled hematite) contains iron(III) oxide. Iron can be extracted from iron(III) oxide using a blast furnace according to the following reactions:
C (s) + O₂ (g) → CO₂ (g)
CO₂ (g) + C (s) → 2 CO (g)
Fe₂O₃ (s) + 3 CO (g) → 2 Fe (l) + 3 CO₂ (g)
Calculate the mass (in kg) of solid carbon required to obtain 1.00×10² kg of iron.

• A. 8.22 kg
• B. 21.5 kg
• C. 50.0 kg
• D. 16.1 kg

Answer: (B)