Generally speaking, having students involved in performing explosive reactions is a really bad idea. However, two experiments used such controlled amounts that you might want to consider using these with mature students.

In the water rocket developed by Bob Becker, both chemical and physical principles come into play. Ron Perkins showed us how to use very small amounts of ethanol that can be combusted in film canisters to demonstrate an explosion. For this experiment, the sparking devices can get to be expensive, and film canisters are likely to become more and more rare as digital cameras become more popular.