What does the fountain experiment demonstrate?

The fountain experiment demonstrates the high solubility of ammonia in water. In this experiment, ammonia gas is generated and then passed into a container of water, where it dissolves readily. The dramatic effect observed in the fountain experiment occurs because of the significant solubility of ammonia, which causes the water to rise up into a vial or tube, creating a fountain-like effect.

When ammonia is added to water, it forms ammonium ions and hydroxide ions, which is a process that emphasizes its solubility. The resulting alkaline solution contributes to the observable phenomenon of the rising water in the fountain setup. This experiment effectively illustrates how ammonia interacts with water, showcasing the concept of solubility in a visually engaging manner.

The other choices center around the production of different gases, the reaction of metals, or the formation of acids, which do not align with the key focus of the fountain experiment, making them less relevant in this context.