Hydrogen Egg Bomb

I have always wanted to do the hydrogen gas/oxygen gas balloon explosion in class, but it isn't very practical or very safe. Once again Steve Spangler shows a much easier and safer way to do the reaction. Of course I had to try it myself and it works beautifully. Making the egg hollow is quite easy as shown here. The most common chemical reaction taught to middle school students is 2H2 + O2 ----> 2H2O. They rarely see it live though. They also have a hard time understanding that water gas is produced by this explosive exothermic reaction (the same chemical reaction that is used in the space shuttle main engines). 

New and Improved Fire Hand

This is a new variation on my "Fire Hand" demonstration. I never did like the size of the methane bubbles that were produced, so I got an idea from a Mythbusters' segment on methane bubbles. They used a tube with many small holes to create the small methane bubbles. I decided to to do a variation of it using aquarium tubing. The result is a bigger handful of methane bubbles which means a bigger flame!

Conservation of Matter: Heavy Whipping Cream

I found a new way to teach the conservation of mass/matter this past year. Previously I taught it by having steel wool (iron) react with oxygen. Since our periods are shorter this year, I couldn't really do that reaction anymore. Now students mix heavy whipping cream and vinegar in an open system. The vinegar reacts with the casein proteins in the heavy whipping cream to form a solid cheese-like substance (basically it is cheese). It's not a very  glamourous reaction, but is also a way to teach students about precipitation. Students have a difficult time understanding the concept of two liquids reacting to make a solid. This is a simple way for students to visualize that type of chemical change.

Flaming Dollar

A dollar bill is soaked in 2 parts water, 2 part isopropyl alcohol, and then lit. The liquid burns off, but the dollar bill doesn't ignite. Watch the video for an explanation.

Video Demo: Watermelon Caviar

I recently started a food science club at school with a fellow teacher.  It's a good way for me to try out new stuff with a small group of students, that I eventually want to incorporate into my classes.  It's like a real life R and D department.  I recently posted about a polymer called sodium alginate. I got a response from Earl Lee on how to make watermelon caviar. So I decided, let's try it out with an after school club.  It demonstrates a technique used in molecular gastronomy. A polymer (which is in one of our standards), sodium alginate, is mixed in with watermelon juice. The mixture is then carefully inserted, with a syringe, into a solution of calcium chloride. A chemical reaction happens between the calcium chloride and sodium alginate to form calcium alginate. The calcium alginate is not soluble in water and thus forms a gel around the outside of the watermelon juice. The calcium alginate watermelon spheres are edible. We then experimented with making spheres of cola using the same technique.  The students loved the more intense (not to mention the more sweet flavor which their palettes are more geared to) flavor of the cola.