You are likely aware that diamonds are converted - albeit slowly - to graphite under normal conditions. Thus, diamonds don't last forever, in contrast to the popular advertising slogan. However, did you know that you can use chemistry to prove that diamonds are not forever? It's simpler than you think...
Phase Transitions / Diagrams
A favorite demonstration is to boil water by lowering the pressure in a bell jar using a vacuum pump. Unfortunately, purchasing a bell jar, vacuum plate, and vacuum pump can run upwards of $1,000 which poses a hardship for many teachers. Here are two simple and inexpensive demonstrations of phase equilibrium and vapor pressure.
Setup: 5 minutes
Execution: 5 minutes to 30 minutes depending on level of inquiry
The science behind the incredibly popular Scrub Daddy sponge is investigated. Part of the appeal of the Scrub Daddy sponge is that it changes from soft to hard depending upon temperature. This allows a single sponge to be transformed into a hard scrubber or soft sponge, depending upon the temperature of water into which it is placed.
Density Bottles can be used to teach a variety of chemical concepts such as density, solubility, and polarity. In this post it is shown that Density Bottles can also be used to differentiate between heterogeneous and homogeneous mixtures, and to explore light scattering.
Lasting Value and High Impact
The May 2017 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: project- and inquiry-based laboratories; measuring value and impact; research on core ideas and clickers; new twists on classic activities; understanding diffraction; acid-base chemistry; teaching informed by technology: flipped learning, biochemistry labs, and scientific computing for chemists; from the archives: chemistry helps feed the world.
I think this experiment provides a fantastic vehicle to involve students of all ages in small, hands-on and exploratory research projects. Like many others, my students and I have investigated various aspects of this interesting fountain.
A 2L soda pop bottle is filled about one-third full with either liquid nitrogen or solid carbon dioxide (dry ice) and water. The bottle is sealed and a plastic bucket is placed on top. Do you think the liquid nitrogen or dry ice and water will make the bucket go higher? Can you explain the results using chemistry?
Can you figure out how this experiment works?
A fun experiment to conduct when discussing phase diagrams is the melting of solid carbon dioxide (dry ice). To perform this experiment, place small pieces of dry ice (carbon dioxide) in a plastic pipette, seal with a pair of pliers, and position the bulb of the sealed pi