Ammonia fountain

The ammonia fountain is a type of chemical demonstration. The experiment consists of introducing

A different gas of comparable solubility in water, such as hydrogen chloride, can be used instead of ammonia.^[2]

If the ammonia is replaced by a liquid vapor, such as water vapor, at a pressure higher than its room-temperature vapor pressure, a similar effect is produced. In this case, the reduction in pressure in the container is due to condensation of the vapor as the container cools to room temperature. Another reported variation involves copper sulfate. ^[3]

References