For this experiment, you need uncooked eggs, aluminum foil and a sewing needle. Poke a hole through the shell of each egg. Wrap each egg in foil, and place outside in the sun during warm or hot weather. Leave the eggs for a week. Throw or crush the eggs to release the "stink bomb." Hydrogen sulfide causes the sulfur stink. Don't inhale this gas for an extended period of time because it deadens the sense of smell and can be toxic. Do not eat the eggs.
Silver polishes and liquids that dissolve tarnish remove some silver every time they are used. Silver tarnishes when it combines with sulfur in the air, forming a coating of black silver sulfide on the silver. This experiment turns silver sulfide back into silver by reversing the chemical reaction. You need tarnished silver, a pan large enough to hold the silver, aluminum foil, a teakettle for boiling water, oven mitts and baking soda.
Line the pan with aluminum foil, and place the silver in the pan. Make certain the silver and foil touch. Boil enough water to cover the silver. Remove from the heat, and add one-half cup baking soda for every one-half gallon of water. Pour the hot water solution over the silver. Badly tarnished silver may need several treatments. Sulfur is more attracted to aluminum than silver, and the sulfur atoms on the silver transfer through the solution to the aluminum, making aluminum sulfide.
This experiment uses sulfuric acid as a dehydrating agent to produce a black sugar "snake" that rises out of the beaker. Concentrated sulfuric acid is corrosive, cobalt chloride paper is toxic and potassium chromate paper is very toxic, and fumes will be released during this experiment. An adult should demonstrate this experiment. You need lab safety glasses for the instructor and all students, a fume cabinet with good visibility, a glass beaker (100cm³), glass stirring rod, white lab tile, a glass measuring cylinder (25cm³), 50g table sugar (sucrose), 20cm³ concentrated sulfuric acid, cobalt chloride paper, potassium chromate paper and distilled water.
Weigh 50g of sucrose. Put it into the beaker. Lightly dampen the sugar with distilled water, and stir. Place the beaker on the white tile, put it into the fume cabinet and clamp it. Carefully add to the sugar the 20cm³ concentrated sulfuric acid, and stir. The sugar will turn yellow, then brown, and after about one minute turn black. The black "snake" (a spongy mass of carbon) will rise out of the beaker, two to three times the height of the beaker, and emit steam and sulfur dioxide. Carefully test the steam with the cobalt chloride paper. It will change from blue to pink. Carefully test with the potassium chromate paper. It will change from orange to blue-green in the presence of sulfur dioxide.
For this experiment, you need lab safety glasses for the instructor and all students, a lab watch glass, 3g blue hydrated copper sulfate and 2cm³ concentrated sulfuric acid. Concentrated sulfuric acid is corrosive and copper sulfate is a poison. Put the hydrated copper sulfate on the watch glass and carefully add the concentrated sulfuric acid. Over several minutes, the color of the hydrated copper sulfate will change from blue to white. The sulfuric acid removes the water from the copper sulfate crystals and produces heat. Use extreme caution in reversing the change by adding water.