Supercooled Liquid, Demo #9

The trihydrate of sodium acetate melts at around 65 degrees and can be cooled back to room temperature without crystallizing.  The supercooled melt is surprisingly stable until exposed to a single see crystal, whereupon the liquid rapidly and exothermically becomes solid.  A visually excellent demo.

Liquid-Vapor Equilibrium & Phase Diagrams, Demo #11

A demonstration to illustrate the fact that water vapor cannot exist at room temperature and one atmosphere pressure (no air present).  The apparatus is just a simple plastic syringe filled with colored water.  No air is in the head space.  It takes a lot of effort to raise the plunger of the syringe in opposition to atmospheric pressure.  When the plunger is released, it crashes back onto the water surface and the vapor phase disappears.

Vapor Pressure of a Pure Liquid, Demo #15

A simple apparatus is used to show that different substances have different equilibirium vapor pressures at a given temperature.  It is also possible to use the apparatus to show that the equilibrium vapor pressure of a liquid is independent of the volume of the container as long as both phases are present.

Boiling & Bubble Formation, Demo #21

A simple demonstration using two connected balloons to illustrate the unappreciated fact that the smaller the balloon (or bubble), the harder it is to expand.  Theoretically, boiling should be impossible.

Solid-Liquid Equilibrium, Demo #25

A simple demonstration showing that water and ice in contact can absorb heat, but maintain the same temperature.

Unit Cell Models, Demo #27

We have many models of different types of unit cells.  There are solid shapes as well as clustered styrofoam balls to illustrate packing.