JAMB Chemistry 2010 Paper

Concept:Carbon (II) oxide, $\mathrm{CO}$, is dangerous because it interferes with oxygen transport in the blood.Explanation:Carbon (II) oxide binds very strongly to haemoglobin in red blood cells.This binding is much stronger than that of oxygen, so $\mathrm{CO}$ displaces oxygen from haemoglobin.As a result, less oxygen is carried to body tissues, which can lead to poisoning or death.Thus, the main danger is that $\mathrm{CO}$ competes with oxygen in the blood.Answer:B. competes with oxygen in the blood.