In the extraction of iron from its oxide ore (haematite) in a blast furnace, which of the following acts as a reducing agent?
Correct: B
In the blast furnace, coke (carbon) reacts with oxygen to form carbon monoxide (CO), which is the primary reducing agent. Carbon monoxide then reduces iron oxides (Fe2O3) to metallic iron. Coke itself can also directly reduce iron oxide at higher temperatures. Limestone (CaCO3) acts as a flux to remove acidic impurities like silica, forming slag.