JAMB - Chemistry (2001 - No. 32)
The main impurity in iron ore during the extraction of iron is
Silicon (IV) oxide
Carbon (IV) oxide
Calcium trioxosilicate
Sulphur (II) oxide
Paliwanag
Iron ore is typically found with various impurities, with the main impurity being silicon dioxide (SiO\(_2\)). To remove silicon dioxide from iron ore, calcium oxide (CaO) is added to the blast furnace. This is a neutralization reaction because silicon dioxide is acidic and calcium oxide is basic.
CaO\(_{(s)}\) + (SiO\(_2\))\(_{(s)}\) → CaSiO\(_2\)\(_{(s)}\).
Base Acid