Chemistry

Pumpkin abuse in the name of science

Over at the Periodic Table of Videos, their chemists put pumpkins through the ringer to demonstrate properties of various chemicals, states, and processes. Nice to see Halloween getting the whole “Peeps in the microwave” treatment. [Thanks, Shawn!] Periodic Table of Videos More: See our own growing collection of chemistry experiments in the Make: Science Room

Flammable ice

This awesome little chemical machine is from Mr. Kent’s chemistry page. Ice is laid in a Pyrex dish over a layer of calcium carbide. As the ice melts, the liquid water reacts with the carbide to produce acetylene gas, which of course is highly flammable. A match starts it off, and then it burns continuously on its own. My first thought was that the system could rapidly spiral out of control–more heat melts more water makes more gas makes even more heat. But it’s limited by the amount of oxygen that can get down into the pan, I think. My second thought was that maybe a bit of sodium metal down there with the carbide could make the process self-igniting…. (For God’s sake, no one try that.)

Super cements aka “geopolymers”

Super cements aka “geopolymers”

Think cement is just cement? Not so. These unlovely mugs are nonetheless very special. Prepared from special synthetic aluminosilicate materials called “geopolymers” (Wikipedia) by members of Dr. Waltraud M. Kriven’s research group at The University of Illinois Urbana-Champaign, these mugs were tested in a special “mug drop” event at the 2004 American Ceramic Society (ACeRS) conference, and supposedly “were impossible to break at even 50ft onto bare concrete.” Danger Room’s David Hambling recently posted a nice overview of geopolymer technology with a view towards defense applications. These presentation slides by Dr. Kriven include some actual formulae.