Silver Acetylide (Double Salts)

This explosive is called double salts because the crystals are an equimolar ratio of silver acetylide and silver nitrate, shown as Ag2C2*AgNO3 or sometimes Ag2C2.AgNO3. Do not get this explosive mixed up with pure silver acetylide as that explosive is highly sensitive and can not be used in detonators. It is made by the reaction of acetylene gas with a solution of silver nitrate in nitric acid.

Ag + 2HNO3 ----> AgNO3 + NO2 + H2O

3AgNO3 + C2H2 ----> Ag2C2*AgNO3 + 2HNO3 (The excess nitric acid which is not displayed here is just to ensure that the double salt is formed)

Silver metal 20x150mm testtube
70% Nitric Acid 50ml testtube or similar device
Acetylene Gas (Prep/OTC) Funnel & filter paper

Into a 20x150mm testtube, place 2 grams of silver metal. Pour 10ml of 70% nitric acidinto the testtube with the silver, then add 10ml of distilled water to this. The distilled water will help the nitric acid dissolve the silver faster. Walk away for about 30 - 60 minutes while it dissolves. This will give off nitrogen dioxide so be sure to use good ventilation. If the silver isn't completely dissolved when you come back, place the testtube in a 70C water bath for a little while. Once it has all dissolved, pour it into the 50ml testtube. Add 30ml of water to it to dilute it a little bit. Begin bubbling acetylene gas into this solution. It will precipitate beautifully as a white material.

Filter the material out and wash with water twice to remove most of the nitric acid. On the last wash, drip the filtrate into a flask containing a saturated sodium chloride solution. If a white precipitate is formed, there is still silver nitrate in the material. Repeat washing and check for precipitate. Nitric acid is more soluble than silver nitrate, so if there is no silver nitrate left, there is no acid left. Thus, 100% pure silver acetylide nitrate. Then wash this with >96% ethanol once and a white powder should remain. Dry in an area protected from dust and other foreign materials as impurites will mess with this stuff. Theoretical yeild = 2.53g. Last time I attempted this synthesis, I obtained 2.5grams. My scale only has a 0.1gram resolution, so I will call it a 98.8% yeild.