Demonstration of an Outdoor Hydrogen/Oxygen Explosion

In the outdoor demonstration presented in this paper, the well-known demonstration of an explosion using a hydrogen/oxygen mixture was modified by adding a water rocket powered by the hydrogen/oxygen explosion. This demonstration employed a PET-bottle water rocket as a hydrogen and oxygen container combined with a small electric bulb as the ignition source. Although many ignition sources, such as piezoelectric devices, Estes rocket igniters, and glow plugs may be available for the ignition of hydrogen/oxygen mixtures, we selected a small electric bulb as an ignition source for two reasons. One is that an electric bulb is so common in everyday life that it can be easily obtained and is familiar to students. The other is to make students understand that a known material can have many different applications. The high temperature of the filament of an electric bulb with the glass removed initiates the explosion of a hydrogen/oxygen mixture in this demonstration.