Script

 

This worked nicely for a 30 min presentation, 4th and 5th graders

 

Chemical properties

 

Burning water

 

            4 new bottle of drinking water

            250 mL ehrlenmeyer flask

            a few drops hexanes (put in flask ahead of time)

matches

extinguishing beaker

 

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 cotton

 

            nitro cottom balls

            propane torch

            ring stand, wire gauze

            glass rod

 

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

 

luminol

 

            250 mL Solution A, 250 mL solution B (Shakhashiri, p. 156)

            500 mL graduated cylander

            Tubing

            Collection flask

            "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

           


acid/base titration

 

            Titration glass wear

            2 x 400 mL 1.25% NaOH solution per demo

            Universal indicator

            Isopropanol

 

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). 

 

Physical properties:

 

liquid nitrogen

           

            liquid nitrogen (-200C, -320F)

balloons

glass dish, dewar

racquetball or other objects to freeze

            tongs, gloves

 

Concept: illustrate physical properties of matter.  Gases.  Relationship of temperature and pressure.  One mole of gas. 

 

 

Other stuff

 

            Benchmat

            waste containers

prizes, tee shirts

goggles

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