JAMB Chemistry 2018 Paper

Concept:Different components of air are removed by different chemical reagents.Explanation:Air contains oxygen, nitrogen, carbon dioxide, water vapour, and rare gases.Alkaline pyrogallol absorbs oxygen gas, so $\mathrm{O}_2$ is removed.Quicklime is calcium oxide, $\mathrm{CaO}$.Quicklime absorbs water vapour, so $\mathrm{H}_2\mathrm{O}$ is removed.Quicklime also reacts with carbon dioxide: $\mathrm{CaO} + \mathrm{CO}_2 \rightarrow \mathrm{CaCO}_3$.Therefore, $\mathrm{CO}_2$ is also removed.The gases left are nitrogen and the rare gases, since they do not react with either reagent.Answer:D. nitrogen and the rare gases