Show
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.
Conductivity Tester Demos
- Sugar and Salt – Use two conductivity testers with light bulbs to contrast the conductivity of d-H2O, sugar solution, and NaCl (aq), and tap water
- Strong and Weak Acids and Bases – Contrast the extent of ionization in weak and strong acids and bases using the lightbulb conductivity apparatus.
Elephant Toothpaste – Demonstrate the decomposition of 30% H2O2 in the presence of dishwashing liquid and KI, producing an upsurge of steaming foam.
He and SF6 balloons – Have adults inhale He or SF6 from balloons and then talk. HI-larious
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.
Pressure Bar – Allow a few students to experience what 1 atm (14.7 psi) “feels” like by resting an iron bar one inch square and 54 inches long on their toes
Rainbow Cups – Add a colorless liquid to 6 “empty” beakers, producing the colors of the rainbow – use this demonstration to show how evaluation of observations and experimental results leads to hypotheses and further testing (the scientific method)
Yamada demos – Add a chunk of dry ice to a 2 L cylinder containing a basic solution and Yamada universal indicator; the dry ice gradually acidifies the solution causing the color to change in the order purple, blue, green, yellow, orange
Hands-on
Alka Seltzer Poppers – React an Alka Seltzer tablet with water in a film canister (placed inside a tube with a ping pong ball on top) to show that the production of gas is so great it pops the top off the film canister and launches the ball
Titanium Rings – Use 9V batteries and an electrolyte solution to anodize titanium rings, depositing a layer of titanium oxide and changing the color of the ring
Baby Volcanoes – Help kids make baby volcanoes using baking soda, vinegar, and food coloring. Bite the tip off of sugar cones and place over tiny Erlenmeyer flasks to make them look more volcano-like
Cats Meow – Have students investigate the effects of soap on fats by having them apply food coloring to small dishes of milk, then add dishsoap with a toothpick
Gooyuck-Oobleck – Pass around bowls of a cornstarch-water mixture; the properties of this non-Newtonian fluid challenge our traditional definitions of liquid and solid (and is awesome).
Hot and Cold Packs – Demonstrate dramatic differences in heats of solution by dissolving NH4NO3(s) in water in a Ziploc bag to make an instant “cold pack” and CaCl2(s) in water to make an instant “hot pack”, then pass the bags around the class
LN2 Ice Cream – Make ice cream using a milk/cream base and liquid nitrogen
Pen Chromatography – Have students make designs or dots on filter paper then use isopropanol, acetone, or ethanol to separate the colors in the pens and markers
Slime (Borax and Glue) – Mix Elmer’s glue and a borax solution (with food coloring) to make an easy cross-linked polymer.
- Can be done in large batches or individually