Chemistry Demos

One of my students, Soon Li, took photos throughout the semester of good demonstrations. Compliments to Jim Maynard for setting up the demos and helping me come up with good ideas.

Here I lit salt solutions on fire to show that different metals have characteristic flame colors.


We revisited the flame tests when we discussed excitation and emission spectra and the Bohr model of the hydrogen atom.


In this image, I mixed bromine gas with potassium metal and released a lot of energy as potassium iodide was formed. I am a bit nervous in the first image and quite relieved in the second image. This demo complimented a lecture on writing chemical equations.



This next image depicts the ethanol cannon. I used a spark to light the ethanol vapor on fire, released a lot of energy (sound), and popped off a cork as water and carbon dioxide were formed. I actually lit off four cannons. The fourth is made from a water-cooler jug, and it's hidden under the bench until a boring part of the lecture. Jim is a great showman, and he recommended hiding it for effect. These demos complimented lectures about stoichiometry and balancing chemical equations.


These balloons were filled with hydrogen and oxygen gas. When I lit the base of the balloon on fire, a lot of energy was released as water was formed. As you can see from the protective ear-gear, the pop is very loud. I could also feel the heat wash over me as the reaction occurred. If Soon Li had caught my expression right after lighting the first one, it would have showed relief that I still had eye brows. This demo complimented a lecture about thermodynamics and state functions.



The drinking bird was one of my last demos of the semester. It's a great application of the gas laws and review of thermodynamics. It also allowed me to talk about the Simpsons during lecture. (Remember the episode where Homer is at home in a Moomoo and used the bird to press the "y" key to keep the nuclear reactor working?)