So, you want to do a “Magic Show!” Student Presenter Packet for y-chem Outreach Program (10/11/2014)



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Collapsing can


A 5 gallon can strong enough to stand on collapses under atmospheric pressure. A small amount of water is added to the can, and boiled, filling the can with hot air. The can is corked, and spun in a tray of ice. The can collapses like an aluminum can.

Warning: Your hands could be crushed if caught in the collapse. Make sure the can is spun using the sides of the can.
Explanation/Teaching

  • When we boil water inside the canister, water vapor is displacing air. In addition, the water vapor is hot. When the can is stoppered, and the water vapor is cooled from steam to water. There are now fewer molecules pushing on the inside of the container than on the outside of the container from atmospheric pressure.

Presentation suggestions

  • Put on the orange heat gloves. Stopper the can very well. Pound it a bit, but don’t hurt your hand. Quickly but carefully stand on it to show that it is strong.

  • Be careful if the gloves are wet. Wet gloves are not good thermal protection from hot objects.

Methanol Cannons


A small amount of methanol is added to 500 mL bottles, and the bottles stoppered. A spark is delivered to the resulting methanol vapor via nails driven in the sides. The methanol vapor ignites, and pops off the stopper with “bang.”

Warning: The telsa coil spark source is an electrocution hazard, handle with care.

Never shock yourself deliberately with the tesla coil.

Explanation

  • Combustion - this is a similar reaction to what happens in your car

  • Fuel and oxygen are mixed, but they don’t react until you provide energy

Presentation suggestions

  • Put the methanol in, and then stare at the cannons, waiting for something to happen.

  • Ask why nothing happens

  • Explain that you have to provide the energy to start the reaction.

  • Turning out the lights can accentuate the flash from the cannons.

Flaming Tornado (12’ ceilings required)


This demonstration generates a 4-5’ tall vortex of fire. A dish of ethanol is spun with a hand crank on the device.

Warning: be aware of close by materials which could ignite (e.g. curtains, ceiling)

A 12’ ceiling is required to do this demo!

Explanation

  • Combustion is a chemical reaction

  • The methanol is reacting with the oxygen in the air to produce water, carbon dioxide, and heat.

  • Oxygen from the air is required for the reaction. O2 is drawn through the screen which causes the flame to spin in the horizontal direction. At the same time, the reaction is producing heat, which causes the product gases to rise; this is vertical component of this spectacular demonstration.


Presentation suggestions

  • Light the methanol, but do not turn the hand crank.

  • Act like it’s the coolest thing that you’ve ever seen, and wait for someone to say “That’s boring!” Then start it up.

  • Turn out the lights to enhance the splendor.

Miscellaneous


Discharge lamps


A high voltage power source generates light emission from various gas tubes. Diffraction glasses are used to observe the spectral differences between the various gases. (H2, He, Ar, Kr, Xe, etc.)
Explanation

  • Electricity is exciting the electrons to higher energy levels – atomic spectra discussion

Presentation suggestions

  • Be careful to hold the discharge tubes by the bulbous part, but not the metal end of the tube. You could be shocked if you forget to turn off the power supply when changing bulbs! Also, be careful the bulbs get quite hot during use.

Elephants Toothpaste


A catalyst is added to a solution of hydrogen peroxide and soap. The accelerated reaction generates a large amount of oxygen causing foam to shoot out of the graduated cylinder holding the original soaping solution.

Warning: the foam is hot for a few minutes and stain skin and clothing
Explanation

  • The graduated cylinder contains H2O2 which is already reaction, but very slowly

  • When you add a catalyst, it speeds up the reaction.

Presentation suggestions

  • Tell the students that there’s a reaction going on in the graduated cylinder. Ask them if they can see it, and then point out that they can’t see it because it’s too slow.


□ Slime


Two clear colorless solutions are added in 1:10 proportions (see bottles). A polymerization reaction proceeds, generating a slimy product safe to handle.

Note: if you choose to use food coloring, be careful of staining clothing, etc.
Explanation

  • Chemistry is used to make polymers long chains of repeating units that stick together well

Presentation suggestions

  • This is safe for students to touch.

Density balloons


The principle of density is demonstrated with three balloons of equal volume. The masses are quite difference because they are filled with helium, air, and sulfur hexafluoride.

Under no circumstances inhale any of these gases!
Explanation

  • Density is a measure of the mass of a given volume of a substance.

Presentation suggestions

  • The contrast of buoyant, neutrally buoyant, and non-buoyant balloons is fun. You can toss the SF6 balloon around like a beach ball, so the students can see it feels like it has water in it.

Nylon rope (no student contact)


Two clear colorless solutions are added to a container forming two phases. Tweezers are used to grab a white film which forms at the phase boundary. As the white film is pulled from the solution, it forms a strand of nylon which is draped around a drum. The drum is turned and a continuous supply of nylon rope is generated.

Warning: These chemical are quite toxic, use the nitrile gloves provided.
Explanation

Presentation suggestions

  • The invention of Nylon 6,6 (A similar compound) changed dentistry

    • Before nylon, toothbrush bristles used to be made of boar hair (wait for a “grooooooosssss!” from the audience.

  • Do not let the students touch the components or the product.

NEXT: Transfer your selections to the next section.


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