The experiment consists of an explosive reaction of potassium with water, in order to classify the reactivity of metals. Potassium is one of the most reactive metals on the list!
Potassium is stored in small amounts in a jar with oil, so that it does not react with oxygen in the air prior to the experiment. Then, the metal is cleaned and placed in a large beaker with water.
Safety apparatus such as glasses, a lab coat and a shield are required for this experiment.
The balanced equation for this reaction is: 2K + 2H2O -> 2KOH + H2