Volume 2
Demonstration Notes
These demonstrations are not meant as tools to teach chemical demonstration techniques. They are meant as a tools for classroom use. Many of the demonstrations present safety hazards or are difficult for an entire class to observe as live demos. If you wish to perform the demonstrations shown here, you should obtain a copy of Shakhashiri's Chemical Demonstrations Vol. 1-4 (1); Gilbert, Alyea, Dutton and Dreisbach's Tested Demonstrations in Chemistry, Vol. I and II (2); Ellis, Geselbracht, Johnson, Lisensky, and Robinson's Teaching General Chemistry: A Materials Science Companion (3); Summerlin and Ealy's Chemical Demonstrations, Vol. 1 (5); and Summerlin, Borgford, and Ealy's Chemical Demonstrations, Vol. 2. (6)
Safety information can be obtained from (4).
Credits for the following text: (142 )
Ammonia Fountain
poison irritant gas
Only a round bottom flask should be used in this demonstration, since a flat bottom flask might implode when the vacuum is created during the demonstration. Ammonia gas is a poison that causes severe irritation or burns to the respiratory system. Phenolphthalein is toxic and should not be ingested.
Ammonia Fountains - Multiple
poisonous irritant gas, toxic chemicals
Only round bottom flasks should be used since flat bottom flasks might implode under reduced pressure. Ammonia gas is poisonous and severely irritating to the respiratory system. Ammonia gas may cause chemical burns to the respiratory system. Acid-base indicators may be toxic.
Big Barometer
poison, poisonous vapors
Potassium mercury iodide and mercury are poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods.
Boiling by Cooling
burns, implosion
Exercise precaution in handling boiling water. Boiling water produces scalding steam. Pressure in the system will decrease with decreasing temperature and the partially evacuated flask should be separated from the audience by an explosion shield. It would be safer to use a round-bottom flask, heated by a heating mantle.
Boyle's Law: J-tube
poison, poisonous vapors
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods.
Canned Heat
burns, flammable
The product burns with an almost invisible flame. Ethanol is flammable.
Colors of Elements in a Flame
burns, chemical irritation
Use caution with the burner. Use standard chemical safety procedures with the solutions.
Conductimetric Titration
toxic, chemical burns
Barium compounds are toxic. Strong acid and strong base solutions are corrosive and caustic. They should be washed off the skin with water if they are touched. Take care in the handling of the reagents.
Critical Point of Benzene
burns, explosion, toxic chemical, carcinogen
Benzene is toxic and carcinogenic. Working with a hot oil bath in excess of 300oC is obviously dangerous. Benzene in the sealed tube will exert an extremely high pressure near the critical point. Have an explosion shield in place the first time the tube is heated to make certain it can hold the pressure.
Crystallization of Supersaturated Sodium Acetate
If this demonstation is attempted in the classroom, be sure to have more than one sample of supersaturated sodium acetate made up. The slightest bump, or addition of dust or other impurity, may cause the solution to crystallize prematurely.
Curie Point of Nickel
burns, toxicity
Use care in handling the hot metal sphere. Nickel metal can be harmful if swallowed or inhaled and is a possible cancer hazard, based on animal data.
Extraction of Acid with Base
flammable, corrosive chemicals, toxic chemicals, poisonous
Diethyl ether is extremely flammable and diethyl ether vapors are poisonous. Sodium hydroxide and hydrochloric acid are corrosive. If spilled on the skin, they should be washed from the skin with water.
Ferrimagnetism
Use normal laboratory precautions.
Ferrofluid
Care should be taken not to spill the ferrofluid; it is very difficult to clean up.
Floating Squares
flammable, poisonous, carcinogenic
Hexane is flammable. Carbon tetrachloride liquid and vapor are poisonous and carcinogenic.
Hardness of Solid Substances
reactive metal, chemical irritants
The silicon disc produces sharp shards when broken and should be handled with gloves. Lithium is a dangerous, reactive metal. Sulfur, selenium and iodine are potentially irritating.
Hardness of Solid Substances - Grinding
chemical irritants, toxicity
Sulfur, selenium, and iodine are potentially irritating. Lead is poisonous.
Heat Conduction by Diamond
Use normal laboratory precautions.
Heat Treatment of a Metal Bobby Pin
burns
Care must be taken when working with a hot flame. The bobby pin should be handled with forceps during the heating process.
Ice Bomb
explosion, frostbite
The acetone used to cool the ice bomb is flammable. The dry ice/acetone slush should not be placed in a glass container, since the exploding bomb could shatter the glass. It is important that the wooden box be placed over the ice bomb to absorb some of the shock and prevent bomb fragments from flying too far. An explosion shield is also necessary. The bomb fragments are initially very cold and should not be handled. Do not go near the bomb if it does not explode within a short time. Allow it to warm up to room temperature before uncovering an unexploded ice bomb.
Induction by Iron(II) of the Oxidation of Iodide by Dichromate
carcinogenic, corrosive solutions
Chromium(VI) compounds are carcinogenic. The solutions in this demonstration are very acidic and strong acids are corrosive. Wash off with water any spilled on the skin.
Isotopes: Heavy Water Ice Cubes
expensive
Deuterium oxide is expensive and should not be wasted.
Like Dissolves Like - Demonstration
flammable, poisonous, carcinogenic
Hexane is flammable. Carbon tetrachloride liquid and vapor are poisonous and carcinogenic. Gloves should be worn when performing this demonstration. (Erratum: The video can be faulted for showing the pouring of carbon tetrachloride without gloves, an error noticed at the very end of the production process.)
Like Dissolves Like - Multimedia Experiments
flammable, poisonous, carcinogenic
Hexane is flammable. Carbon tetrachloride liquid and vapor are poisonous and carcinogenic.
Liquefaction of Carbon Dioxide
frostbite, explosion
To avoid frostbite, dry ice should not be handled for more than a second or so without gloves. The confined carbon dioxide gas is at great pressure and presents an explosion hazard.
Memory Metal
Care should be taken not to burn fingers when immersing the metal in the hot water bath. Special care must be taken to prevent burns when heating the metal to 500oC to "teach" it a shape.
Mercury Barometers
poison, poisonous vapors
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods.
Osmotic Pressure, Hydrostatic Pressure
Use normal laboratory precautions.
Paramagnetism: Compounds
carcinogenic
Nickel(II) sulfate hexahydrate is a suspect carcinogen and is harmful if swallowed, inhaled, or absorbed through the skin. Zinc(II) sulfate heptahydrate is harmful if swallowed.
Paramagnetism: Nitrogen and Oxygen
frostbite, combustion
Avoid skin contact with liquid oxygen or liquid nitrogen, since both can cause severe frostbite. Combustion rates in the presence of liquid oxygen are extremely high due to the high O2 concentration.
Paramagnetism: Oxidation States of Manganese
chemical irritants
In preparing the sealed tubes, care needs to be taken in handling the chemicals.
Piezoelectric Effect
Use normal laboratory precautions.
Plastic Sulfur
burns, toxic, irritant gas
Because sulfur dioxide is produced when sulfur is burned, this demonstration should be carried out in a hood. Sulfur dioxide is toxic and a strong irritant with a powerful choking odor. The plastic sulfur may contain molten sulfur at first and is quite hot. It should be handled with caution.
Relative Reactivity of Alkali Metals
explosions, flammable, exothermic
Alkali metals react violently with water. The hydrogen gas that is produced bursts into flame because of the reaction heat. The resulting solutions are strongly alkaline. Exposure of skin to these metals or the reaction products should be avoided.
Ring Strain
flammable, explosive, chemical irritant
Cyclohexene and
-pinene are flammable. The reaction of
-pinene and iodine is very exothermic, producing dense iodine vapors,
which can irritate the respiratory tract.
Simulation of Dislocations in Metals
Use normal laboratory precautions. Be careful with the sharp needle.
Sodium Chloride Crystal Cleavage
It is difficult to grow a crystal suitable for this demonstration. Because the crystal is so small, it is difficult for a large group of students to see the demonstration if performed live.
Superconductivity
frostbite
Avoid skin contact with liquid nitrogen, because it can cause frostbite.
Thermochromism: Mercury(II) Iodide
toxic, burns
Mercury compounds are toxic. Be careful in removing the hot HgI2 from the hot plate.
Vapor Pressure: Collapsing Balloon
burns, scalding steam
Use caution with the hot plate and boiling water that creates scalding steam.
Vapor Pressure: Drinking Bird
burns, fragile
Use caution with the heat lamp. The bird is fragile and easily broken.
Vapor Pressure: H-bonding vs. dipole-dipole attraction
poison, poisonous vapors, equipment breakage and chemical spills, flammable
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods. Sudden changes in pressure as substances are injected into the barometer can cause breakage hazards. Diethyl ether is extremely flammable and diethyl ether vapors are poisonous. Butanol is flammable and moderately toxic.
Vapor Pressure: Molecular Polarity
poison, poisonous vapors, equipment breakage and chemical spills, flammable, carcinogenic
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods. Sudden changes in pressure as substances are injected into the barometer can cause breakage hazards. Chloromethane and dichloromethane are flammable, harmful if swallowed, inhaled, or absorbed through the skin, and may be carcinogenic.
Vapor Pressure: Molecular Size
poison, poisonous vapors, equipment breakage and chemical spills, flammable
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods. Sudden changes in pressure as substances are injected into the barometer can cause breakage hazards. Methanol, ethanol, pentane, hexane, and heptane are all very flammable. Methanol is poisonous if swallowed and can cause blindness. Ethanol is poisonous. Pentane, hexane, and heptane are skin irritants and are hazardous if ingested or inhaled.
Vapor Pressure of a Mixture: Raoult's Law
poison, poisonous vapors, equipment breakage and chemical spills, flammable
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods. Sudden changes in pressure as substances are injected into the barometer can cause breakage hazards. Diethyl ether is extremely flammable and diethyl ether vapors are poisonous. Decane is flammable. It is harmful if ingested or inhaled and is readily absorbed through skin.
Vapor Pressure: Using Barometers
poison, poisonous vapors, equipment breakage and chemical spills, flammable
Mercury is poisonous. The mercury vapors from open containers of mercury are above the maximum safe exposure limit. Mercury spills should be cleaned up promptly with approved mercury spill cleaning methods. Sudden changes in pressure as substances are injected into the barometer can cause breakage hazards. Ethanol is flammable.
Viscosity of Liquids
volatile, flammable, toxic
Rubbing alcohol and ethylene glycol are flammable and toxic. Ethylene glycol causes central nervous system depression, cardiopulmonary failure, and kidney failure.
Citations
1. Shakhashiri. B. Z. Chemical Demonstrations; University of Wisconsin press: Madison, 1983; Vol. 1.
Shakhashiri. B. Z., Chemical Demonstrations; University of Wisconsin press: Madison, 1985; Vol. 2.
Shakhashiri. B. Z., Chemical Demonstrations; University of Wisconsin press: Madison, 1989; Vol. 3.
Shakhashiri. B. Z., Chemical Demonstrations; University of Wisconsin press: Madison, 1992; Vol. 4.
2. Gilbert, G. L.; Alyea, H. N.; Dutton, F. B.; Dreisbach, D. Tested Demonstrations in Chemistry; Denison University and Journal of Chemical Education: Granville, OH, 1994.
3. Ellis, A. B.; Geselbracht, M. J.; Johnson, B. J.; Lisensky, G. C.; Robinson, W. R. Teaching General Chemistry: A Materials Science Companion, American Chemical Society, Washington, DC, 1993.
4. University of Wisconsin System Administration OSLP EHS MSDS Database; http://www.uwsa.edu/oslp/ehs/msds98-1/ Try this link if you are connected to the web.
5. Summerlin, L. R.; Ealy, J. I., Jr. Chemical Demonstrations, Vol. 1, 2nd Ed., American Chemical Society, Washington, DC, 1988.
6. Summerlin, L. R.; Borgford, C. L.; Ealy, J. B. Chemical Demonstrations, Vol. 2, American Chemical Society, Washington, DC, 1987.