Phase Transitions / Diagrams

The Liquid Nitrogen Cloud

Have you ever seen the liquid nitrogen cloud? Do you wonder how the cloud forms when hot water is thrown onto liquid nitrogen? This post explores the liquid nitrogen cloud and possible explanations for its formation.

Two Simple and Cheap Illustrations of Phase Equilibrium and Vapor Pressure

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.

Scrub Daddy Science

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.

The Density Bottle Strikes Again

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.    

Melting Pennies

I am fascinated by the chemistry of pennies. I have tried several experiments found in the Journal of Chemical Education.