Genie in a Bottle
Materials:
- Hydrogen peroxide (H2O2) 30%
- Manganese dioxide (MnO2)
- Mortar and pestle
- Clean two liter bottle
Procedure:
There are a few way in which this demo can be presented. The first way is to present the story of Aladdin's magic lantern. For this method, place a small amount of MnO
2 in a kem wipe and tie the kem wipe together with a piece of string. Hang the string from the opening of the bottle and secure the string with a rubber stopper so that the kem wipe and MnO
2 rest just above the level of hydrogen peroxide. As you tell the story of Aladdin's magic lamp, the rubber stopper can be removed to allow the kem wipe to fall into the hydrogen peroxide. Steam and smoke will vigorously pour from the mouth of the bottle. Then you can go on and explain the reaction.
The second method that can be used for groups with more chemistry background is to set up by explaining the function of a catalyst within chemical reactions. Be sure to stress that a catalyst is not used in the reaction, it only supplies an alternate pathway that does not require as much energy to overcome. Mention that since the catalyst is not used, it can be recovered when the reaction is complete.
Without the catalyst, the decomposition of hydrogen peroxide will occur, but the reaction time is on the orders of years to go to completion. By using the MnO
2, the reaction time is speeded up so that it occurs instantaneously.
Colored Flames:
Colored Fire Chemicals
dark red = lithium chloride
100g
red = strontium chloride (found in emergency flares)
100g
orange = calcium chloride (a bleaching powder)
500g
yellow = sodium chloride (table salt) or sodium carbonate
1lb
yellowish green = borax (sodium borate, a common insecticide and cleaning agent)
1lb.
green = copper sulfate (found in some pool and aquarium chemicals) ,
500g
blue = copper chloride (lab chemical, but other copper compounds found in algicides and fungicides may work)
125g
violet = 3 parts potassium sulfate, 1 part potassium nitrate (saltpeter)
purple = potassium chloride (sometimes sold as a 'lite' salt)
100g
white = magnesium sulfate (Epsom salts)
12"
Prepare the Flame Colorants
If you were just coloring a campfire or other wood fire, you could simply sprinkle the dry metal salts onto the fire. Copper chloride is especially nice for this since the sodium that is naturally present in wood causes this chemical to produce a mix of blue, green, and yellow flames. However, for the gas flame in a burner, you need the salts dissolved in a flammable liquid. The obvious choice here is alcohol. Common alcohols found around the home could include rubbing alcohol (isopropyl alcohol) or ethanol (e.g., in vodka). In some cases, the metal salts will first need to be dissolved in a small volume of water and then mixed with alcohol so that they can be spray onto a flame. Some salts may not dissolve, so what you can do is grind them into a fine powder and suspend them in liquid.
Links:
http://www.instructables.com/id/Genie-In-A-Bottle/ and
http://chemistry.about.com/od/funfireprojects/a/coloredfire.htm
and
http://www.sciencecompany.com/sci-exper/flamecolors.htm
and http://www.chem.umn.edu/outreach/Genie.html