 We filled a one liter round bottom flask with ammonia gas. We're going to put in a medicine dropper that's sealed with a little bit of grease. The medicine dropper contains a small amount of water and phenothaline, which is an acid-based indicator. We're going to lower the tube connected to the round bottom flask into a large beaker of water. We're going to inject the water from the dropper into the flask. The ammonia gas is very soluble in the water and very rapidly dissolves in the water, creating a low pressure situation inside the flask. Atmospheric pressure will force the water up into the flask. We get a fountain. The solution is pink because ammonia dissolved in water is basic and turns the acid-based indicator pink.