CTET Paper I (Classes I to V) 3 Jan 2022 Solved Paper

Concept:Incomplete combustion of fossil fuels occurs when there is insufficient oxygen. This produces carbon monoxide (CO) instead of carbon dioxide.Explanation:Fossil fuels contain carbon. In complete combustion with enough oxygen, carbon dioxide ($CO_{2}$) forms. In incomplete burning, the carbon only partially oxidizes. This yields carbon monoxide (CO), a toxic, colorless, odorless gas. CO is dangerous because it binds strongly to hemoglobin in blood. This prevents oxygen from being carried to body tissues. Common sources of CO include vehicle exhaust, coal stoves, and firewood. In contrast, complete burning gives $CO_{2}$, and other pollutants like $SO_{2}$ or NO come from other chemical reactions, not from incomplete combustion.Answer:A. CO