Preparation of mercury ii fulminate/mercury fulminate
mercury ii fulminate: 5 g of metallic mercury is added to 35 ml of concentrated nitric acid (d=1.42 g/ml) in a 100-ml Erlenmeyer flask, and the mixture is allowed to stand without shaking until the mercury has gone into solution. The acid liquid is then poured into 50 ml of 90% alcohol in a 500-ml beaker in the hood. The temperature of the mixture rises, a vigorous reaction commences, white fumes come off, and crystals of mercury ii fulminate soon begin to precipitate. `
Red fumes appear and the precipitation of the fulminate becomes more rapid, then white fumes again as the reaction moderates. After about 20 minutes the reaction is over; water is added, and the crystals are washed with water repeatedly by decantation until the washings are no longer acid to litmus. The product consists of grayish-yellow crystals.
Mercury(II) fulminate may be obtained white and entirely pure by dissolving in strong ammonia water, filtering, and reprecipitating by the addition of 30% acetic acid. The pure mercury ii fulminate is filtered off, washed several times with cold water, and stored under water, or, if a very small amount is desired for experimental purposes, it is dried in a desiccator.
Chemistry of Powder and Explosives, by T. L. Davis, 406-407, 1941