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



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Gun Cotton (Nitrocellulose)


  • Cotton is soaked in an acid solution to form nitrocellulose, which completely combusts in a smokeless flame.
  • Safety


  • When preparing gun cotton, do all steps in the hood. Toxic gases may evolve. Use caution when working with concentrated acid solutions, they are extremely corrosive. Never ignite the Gun Cotton in your hand.
  • Disposal


  • After the ashes and charred remains have cooled down (be sure of this), dispose of them in the trash.


  • Chemistry


  • Gun cotton is nitrocellulose C6H7N3O11 cotton. Cotton balls, which is 90% cellulose C6H7O5, are placed in fuming nitric acid. The hydroxyl groups on the cellulose are replaces with nitro groups.





  • When lit, the cotton goes up into a ball of smokeless flame from complete combustion.
  • Presentation


  • Burn cotton on the ceramic tile, then, using tongs, grab some gun Cotton and set it on the remaining smoldering cotton. It should go up in a flame immediately.
  • Collapsing Can Demonstration


  • This demonstrates atmospheric pressure by creating a partial vacuum in a can, causing external atmospheric pressure to crush it.
  • Set Up


  • Fill the can with about an inch of water and then set it on top of the hot plate with the hot plate on high (l0). It will take at least 10 minutes for the water to be heated enough to where it is readily streaming out of the can. Have the ice tray nearby.
  • Safety


  • Boiling water can cause burns, so use the orange heat gloves to hold the can. DO NOT ALLOW THE HOT GLOVES TO GET WET, OR THEY WILL CEASE TO INSULATE!
  • Disposal


  • Empty water from can into drain. Dump the ice down the sink.
  • Chemistry


  • Water vapor replaces the air in the can as it is heated. When the can is sealed and cooled, the vapor condenses, creating a low-pressure system on the inside of the can. The relatively high pressure outside the can causes it to be crushed.
  • Presentation


  • Do not attempt until steam is visibly coming out of the top of the can and has boiled for a few minutes to push the air out and allow the water vapor to fill the can, but do not let it boil to dryness Wearing gloves, take the can off the hot plate and tightly stopper the can. Put the can in the ice, and roll it to get the best results. The can will implode quickly. Watch your fingers! DO NOT THE WALLS OF THE CAN- ONLY HANDLE LID AND BASE- OTHERWISE YOUR FINGERS WILL BE PINCHED WHEN THE CAN COLLAPSES.
  • Flaming Tornado


  • Burning alcohol in a beaker surrounded by a mesh wire column, a vortex of fire is generated. Using inorganic salts the color of the vortex can be changed.
  • Set Up


  • Bring out all equipment. Place crystallization dish inside the metal beaker in the middle of the turntable. Pour about 300 mL ethanol into beaker. Add a small amount of an inorganic salt (or a combination). Some choices include CuCl2 (green), KMnO4 (purple), LiF (magenta), NaCl (yellow) and SrCl2 (red). Place mesh cover next to apparatus.
  • Safety


  • Be very careful with the apparatus after you start the flame – the metal can get very hot. If the apparatus runs for long enough the glass may break. If this occurs clean up the pieces carefully.
  • Clean Up


  • Ensure that all the ethanol has dried/burned before transporting the tornado. No cleanup is required.
  • Chemistry


  • When atoms are exposed to heat, their electrons are excited and promoted to a higher energy level. As they return to their lowest-energy state, they emit the extra energy as photons (light packets). Each salt’s unique color corresponds to its elements’ own differences in energy levels.
  • Presentation


  • Use the lighter to ignite the ethanol. Place the aluminum mesh over the apparatus, sliding it into the sheath. Turn out the lights and turn the handle of the apparatus. The ethanol initially burns yellow. The flame will change colors as the salt(s) diffuse. Abruptly stopping the turntable and then turning it the other direction often shows a color change. To extinguish the flames, remove the mesh with caution as it may be hot, and cover the beaker with the pie dish.
  • Elephant’s Toothpaste


  • A small amount of KI is put into a solution of hydrogen peroxide and dish soap, and yellowish-white foam shoots out of the graduated cylinder.
  • Safety


  • This demo is exothermic and the foam created has 30% hydrogen peroxide in it. Do not touch it or allow anyone else to do so. Also be careful when setting up and demonstrating not to use too much solution, because it will overflow the plastic tray and make a mess.
  • Disposal


  • Wait until students are gone, and (using the provided gloves) wash this demonstration out in a large sink (ask if there’s a janitor’s closet you can use) Wash everything in the sink; all the chemicals can be disposed of that way.
  • Chemistry


  • This reaction demonstrates the decomposition of hydrogen peroxide (H2O2) with a potassium iodide catalyst. It is a two-step reaction:



  • H2O2 (aq) + I (aq) → H2O (l) + OI (aq) (rate determining step)



  • H2O2 (aq) + OI (aq) → H2O (l) + O2 (g) + I- (aq)



  • The brown, yellow color of the foam indicates the presence of iodine in solution as the I3-(aq) species as a possible side reaction.

  • The dish soap just acts to collect the oxygen gas as it is evolved.
  • Presentation


  • Make some comments about having elephants and needing toothpaste and then dump the KI into the graduated cylinder.
  • Nylon Rope Demonstration


  • A nylon thread is formed when two immiscible liquids are mixed. The nylon rope can be pulled to extensive lengths using forceps or wound on a windlass (crank).
  • For demonstration


  • Gather two 1 liter stock bottles, one labeled “Nylon Rope Top Solution”, and the other labeled “Nylon Rope Bottom Solution”. Also, set out the windlass on a stand.
  • Safety


  • All these reagents are very toxic and cause nausea. Make sure you prepare all of these solutions in the hood and wear protective eyewear and gloves.
  • Chemistry


  • Nylon, or synthetic polyamides, are formed from diamines and dibasic acids and are designated by one number for each. In this demonstration we form 6-10 nylon with hexamethylenediamine and sebacic acid, although the sebacic acid is represented by sebacoyl chloride in the reaction shown:



  • H2N(CH2)6NH2 + ClCO(CH2)8COCl  [HN(CH2)6HN-CO(CH2)8CO] + 2 HCl



  • This type of reaction is called interfacial polycondensation. It is especially useful because it is a low temperature process, and will react rapidly at room temperature. Another beneficial component of this reaction is that it does not require exact stoichiometric ratios.



  • Nylon 6-6, a commercially used polyamide, can be made by substituting adipoyl chloride for sebacoyl chloride.



  • H2N(CH2)6NH2 + ClCO(CH2)4COCl  [HN(CH2)6HN-CO(CH2)4CO] + 2 HCl


  • Presentation


  • Pour some of the bottom solution into the beaker, then pour an equal amount of the top solution onto the bottom solution. With the tweezers, grab the interface between the two liquids and pull it up and above the beaker. Begin to twist the tweezers to show the continuous thread of nylon formed or use the windlass provided to wind it.



  • To show the interface better, use food coloring or phenolphthalein in the bottom solution.
  • Disposal


  • Place the solutions in the appropriate “nylon rope” waste.
  • Misc. notes/Performance


  • The nylon rope can be stretched to great lengths. To emphasize this, you can put the beaker on the floor, stand up on the desk, and use the forceps to pull the nylon as high as your arms can reach. The string can then be wound around a windlass to further demonstrate the length.

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