The “Self-Carving Pumpkin” demonstration is a great way to have students learn about hydrocarbons and combustion reactions (I was unable to upload a video without an upgrade, so I’ve posted three pictures in order of how the demo goes). This fun demo works by pre-cutting the face of the jack-o-lantern and then placing the pieces back into the pumpkin. Two small holes are also drilled into the pumpkin. One is used to pull a gas grill ignitor through the pumpkin and the other is used to add the hydrocarbon into the pumpkin. After the explosive is added … count to ten … and pull the trigger.
With the right equipment and supervision, this is a great demonstration that the students themselves can perform. In the video above, you see two of my 12th grade (second-year chemistry) students performing the act. These students were graded on their ability to execute the task at hand (along with other Halloween Chemistry activities), but also in their ability to teach these concepts to my 11th grade (first-year chemistry) students.