JAMB Chemistry 2024 Paper

Concept:An air pollutant is a gas or small particle in the atmosphere that is harmful to living organisms or the environment.Explanation:Carbon monoxide ($\mathrm{CO}$) is a well-known air pollutant. It is a colourless, odourless gas formed by the incomplete combustion of fuels such as petrol, coal, and wood. When inhaled, $\mathrm{CO}$ combines with haemoglobin in the blood much more easily than oxygen does. This reduces the oxygen supply to body tissues and can cause dizziness, unconsciousness, or death. Oxygen ($\mathrm{O}_2$) is normal atmospheric gas and is not a pollutant because it supports life. Water vapour ($\mathrm{H}_2\mathrm{O}_{(g)}$) is naturally present in air as part of the water cycle and is also not a pollutant. Ozone ($\mathrm{O}_3$) in the stratosphere is beneficial because it protects the earth from harmful ultraviolet rays; it is not treated as a primary air pollutant in this context.Therefore, the option that represents an air pollutant is carbon monoxide.Answer:B. $\mathrm{CO}$