JAMB Chemistry 2019 Paper

Concept:The fountain experiment requires gases that are highly soluble in water.Explanation:When a highly soluble gas dissolves rapidly in water, it creates a large pressure drop inside the flask, causing water to rise like a fountain.Both ammonia ($\mathrm{NH}_3$) and hydrogen chloride ($\mathrm{HCl}$) are extremely soluble in water.Therefore, they are commonly used together for the demonstration of the fountain experiment.Answer:C. $\mathrm{HCl}$ and $\mathrm{NH}_3$