Dictionary Thesaurus Word Dynamo Quotes Reference Translator Spanish

Lead(II) azide

Lead azide (Pb(N₃)₂) is an explosive and toxic crystalline compound. It is used as a detonator for other, secondary, explosives. The white crystals have a density of 4.71 g/cm³. In a commercially usable form it is a white-to-buff powder.

Stability

Lead azide is not very hygroscopic, and water does not reduce its impact sensitivity. When protected from humidity, is completely stable in storage.

Preparation

Lead azide is prepared by metathesis between sodium azide and lead nitrate or lead dissolved in nitric acid. Dextrose can be added to the solution to stabilize the product.

Exploding bullets

Lead azide was one of the ingredients of the six .22 caliber Devastator rounds fired by John Hinckley, Jr. in his assassination attempt on President Ronald Reagan on March 30, 1981. The rounds consisted of lead azide centers with lacquer-sealed aluminum tips designed to explode upon impact. None of the six bullets hit the president directly. The one that did strike the President in the chest after ricocheting off of the bullet proof glass of the presidential limousine did not explode as designed. Nor did the other five, though three others were wounded, including press secretary James Brady who was partially paralyzed.

Safety

Lead azide is highly sensitive and usually handled and stored under water in insulated rubber containers. It will explode after a fall of around 150 mm (6 in) or in the presence of a static discharge of 7 millijoules. Its detonation velocity is around 5.18 km/s (17,500 ft/s).

Ammonium acetate and sodium dichromate are used to destroy small quantities of lead azide.

Lead azide reacts with copper, zinc, cadmium, or alloys containing these metals to form other azides. For example, copper azide is even more explosive and too sensitive to be used commercially. Sodium azide is used both for the manufacture of lead azide and as preservative and diluent, which can lead to problems.