Gases

 

Boiling Water at Room Temperature – Show water boiling at room temperature in a beaker in an evacuated bell jar, then put your hand in the water after boiling to convince students of its low temperature.

Charles’ Law – Pour liquid nitrogen over a balloon to show that a decrease in T is accompanied by a decrease in V.

Graham’s Law of Diffusion – Allow concentrated NH3 and concentrated HCl to vaporize and meet in a horizontal glass tube, forming a ring of NH4Cl.

Lake Nyos Demo – Pour CO2 (g) down an enclosed set of steps to extinguish candles on each step, demonstrating the fluidity of gases, and recreating (on a small scale) a tragic natural disaster.

Marshmallow Snowman – Demonstrate the effect a decrease in P has on V by placing a marshmallow snowman in a bell jar and then evacuate the jar.

Potato Rifle – Use a “potato rifle” (long pipe with two potato cores) to dramatically demonstrate the effect a decrease in volume has on pressure.

Solution Formation at Different Temperatures – Drop crystals of KMnO4 into crystallizing dishes of hot and cold water on the overhead projector to show diffusion of the dissolving ions due to random motion of molecules in the liquid AND to show that kinetic energy increases with temperature

Squashing Pop Cans with Atmospheric Pressure – Use atmospheric pressure to squash pop cans.