explodes at 150 °C
|mercury fulminate||molecular mass
Mercury fulminate is an unstable primary explosive compound. It was first prepared in the late seventeenth century by Johann Kunckel von Löwenstern by a procedure very similar to the modern method presented here. Löwenstern detailed mercury fulminate synthesis in his posthumously written Laboratorium Chymicum, he used aqua fortis, spiritum vini, and in fimum equinum. That last one is horse manure if you wanted to know. Mercury fulminate was first patented by Alfred Nobel in 1867 for blasting caps. It is not used today for that purpose because of more stable explosives from modern chemistry. Its manufacture is not complicated nor the chemicals in its makeup rare. Mercury can be extracted from a variety of products but it is very expensive. Only a chemical supply company could provide mercury in useful quantities. This lab produces nitrogen dioxide gas as a byproduct, this is a heavy red colored gas that is extremely toxic. The gas will turn moisture in your lungs to nitric acid and may cause fabric to ignite! This lab should be done outside or in a fume hood if possible.
|acetic acid||500-mL beaker|
|ethyl alcohol||100mL Erlenmeyer flask|
In a 100mL Erlenmeyer flask, measure out 35 mL of 70% nitric acid, then add 5 g of mercury metal. This mixture should be left alone without shaking or stirring until all the mercury dissolves. Toxic gas will be produced. Keep the flask in a well ventilated area, or stopper the flask and lead a length of rubber tubing into water to safely dissolve the fumes. In a 500-mL beaker, place 50 mL of 90% ethyl alcohol, then add the acid-mercury mix in a well ventilated area. The temperature of the mixture will rise, a vigorous reaction will commence, white fumes will be released, and crystals of mercury fulminate should begin to precipitate. Red fumes of nitrogen dioxide will appear as the precipitation becomes more rapid, then white fumes again as the reaction moderates. After about 20 minutes the reaction should be over. Add water to the beaker and carefully decant off most of the water without losing any crystals. Add water and decant several times until the wash water is no longer acid to litmus. Finally, pour the neutral solution over a filter to collect the grayish-yellow crystals of mercury fulminate. The product may be purified by dissolving in strong ammonium hydroxide, filtering, and re-precipitating by the addition of 30% acetic acid. The pure fulminate is filtered off, washed with cold water, and stored in a container filled with water. Dry in a desiccator immediately before use. You will need a graduated cylinder for measuring liquids.
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