This worked nicely for a 30 min presentation, 4th and 5th graders
4 new bottle of drinking water
250 mL ehrlenmeyer flask
a few drops hexanes (put in flask ahead of time)
Talk about matter (the stuff of the universe, solid liquids and gases), observations, how the unexpected can be a good thing.
combustion reaction: hydrocarbon (C, H) + oxygen forms carbon dioxide and water
the rearrangement of atoms (C, H) in these molecules to form new, more stable molecules, releases energy (heat and light)
nitro cottom balls
ring stand, wire gauze
Would the first combustion reaction be enough energy to fuel a rocket? Rocket fuel contains different atoms arranged in a way that when burned they release a lot more energy (heat and light)
combustion reaction: C, H, N, O + oxygen forms carbon dioxide, nitrogen gas, water and heat and light
250 mL Solution A, 250 mL solution B (Shakhashiri, p. 156)
500 mL graduated cylander
"Wand" and HP reference to "Lumos" spell
Concept: production of light without heat. Not a combustion reaction but a transfer of electrons in an oxidation-reduction reaction
Titration glass wear
2 x 400 mL 1.25% NaOH solution per demo
Concept: acid base reactions (vinegar and baking soda, ammonia, cleaners, lemon juice, soda etc). Purple color indicates a basic solution (pH > 7). As acid is added the solution turns yellow indicating pH < 7. Have students race to be the first to add enough acid to neutralize all the base. Acid is added in the form of exhaled CO2 (blown through tubing).
liquid nitrogen (-200C, -320F)
glass dish, dewar
racquetball or other objects to freeze
Concept: illustrate physical properties of matter. Gases. Relationship of temperature and pressure. One mole of gas.
prizes, tee shirts