Different colors of LED light illuminate a small corked test tube with no reaction. Ultraviolet light causes an explosion that shoots the cork across the room.
The gas mixture is made by the electrolysis of hydrochloric acid 8M. A water bath allows for filling the tubes under water. The tubes are quartz. There should be a video of how to fill one of these tubes, because many words otherwise.
* Richard Schwenz and Lynn Geiger. "Photon-Initiated Hydrogen-Chlorine Reaction." Journal of Chemical Education 76.4 (1999): 470.
* Shakhashiri, Bassam Z. "Chemical Demonstrations: A Handbook for Teachers of Chemistry." Madison: The University of Wisconsin Press, 1983. ( http://books.google.com/books?id=0rx6Cjx_l-AC&lpg=PP1&pg=PA121#v=onepage&q&f=false)