Lead(II) azide
Encyclopedia
Lead azide is an inorganic compound
. More so than other azide
s, is explosive. It is used in detonator
s to initiate secondary explosives. In a commercially usable form, it is a white to buff
powder.
between sodium azide
and lead nitrate
. Dextrin
can be added to the solution to stabilize the precipitated product. The solid is not very hygroscopic, and water does not reduce its impact sensitivity. It is normally shipped in a dextrinated solution that lowers its sensitivity. When protected from humidity, it is completely stable in storage. An alternative synthesis pathway involves dissolving lead acetate in a sodium azide solution.
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.
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
. More so than other azide
Azide
Azide is the anion with the formula N3−. It is the conjugate base of hydrazoic acid. N3− is a linear anion that is isoelectronic with CO2 and N2O. Per valence bond theory, azide can be described by several resonance structures, an important one being N−=N+=N−...
s, is explosive. It is used in detonator
Detonator
A detonator is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the latter two being the most common....
s to initiate secondary explosives. In a commercially usable form, it is a white to buff
Buff (colour)
Buff is a pale yellow-brown colour that got its name from the colour of buff leather.Displayed on the right is the colour buff.EtymologyAccording to the Oxford English Dictionary, buff as a descriptor of a colour was first used in the London Gazette of 1686, describing a uniform to be "A Red Coat...
powder.
Preparation and handling
Lead azide is prepared by metathesisMetathesis (chemistry)
Salt metathesis is a molecular process involving the exchange of bonds between the two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations. This is represented by the general reaction scheme:These chemical species can either be ionic...
between sodium azide
Sodium azide
Sodium azide is the inorganic compound with the formula NaN3. This colourless azide salt is the gas-forming component in many car airbag systems. It is used for the preparation of other azide compounds. It is an ionic substance and is highly soluble in water. It is extremely...
and lead nitrate
Lead(II) nitrate
Lead nitrate is an inorganic compound with the chemical formula Pb2. It commonly occurs as a colourless crystal or white powder and, unlike most other lead salts, is soluble in water....
. Dextrin
Dextrin
Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch or glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α- or α- glycosidic bonds....
can be added to the solution to stabilize the precipitated product. The solid is not very hygroscopic, and water does not reduce its impact sensitivity. It is normally shipped in a dextrinated solution that lowers its sensitivity. When protected from humidity, it is completely stable in storage. An alternative synthesis pathway involves dissolving lead acetate in a sodium azide solution.
Explosive characteristics
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 velocityExplosive velocity
Explosive velocity, also known as detonation velocity or velocity of detonation , is the velocity at which the shock wave front travels through a detonated explosive. The data listed for a specific substance is usually a rough prediction based upon gas behavior theory , as in practice it is...
is around 5.18 km/s (17,500 ft/s).
Ammonium acetate
Ammonium acetate
Ammonium acetate is a chemical compound with the formula CH3COONH4 . It is a white solid, which can be derived from the reaction of ammonia and acetic acid...
and sodium dichromate
Sodium dichromate
Sodium dichromate is the chemical compound with the formula Na2Cr2O7. Usually, however, the salt is handled as its dihydrate Na2Cr2O7·2H2O. Virtually all chromium ore is processed via conversion to sodium dichromate. In this way, many millions of kilograms of sodium dichromate are produced...
are used to destroy small quantities of lead azide.
Lead azide
Azide
Azide is the anion with the formula N3−. It is the conjugate base of hydrazoic acid. N3− is a linear anion that is isoelectronic with CO2 and N2O. Per valence bond theory, azide can be described by several resonance structures, an important one being N−=N+=N−...
reacts with copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
, or alloys containing these metals to form other azides. For example, copper azide is even more explosive and too sensitive to be used commercially.