Lead(II) azide

Lead(II) azide
Identifiers
PubChem 61600
Properties
Molecular formula Pb(N3)2
Molar mass 291.24 g/mol
Appearance white powder
Density 4.71 g/cm3, solid
Melting point

350 °C (explodes)
Solubility in water 2.3 g/100 mL (18 °C)
9.0 g/100 mL (70 °C)[1]
Solubility very soluble in acetic acid;
insoluble in ammonia
Explosive data
Shock sensitivity High
Friction sensitivity High
Explosive velocity 5180 m/s
Hazards
Main hazards Harmful, Explosive
Autoignition
temperature		 350 °C
Related compounds
Other cations Potassium azide
Related compounds Hydrazoic acid
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Lead azide (Pb(N3)2) is an inorganic compound. More so than other azides, Pb(N3)2 is explosive. It is used in detonators to initiate secondary explosives. In a commercially usable form, it is a white to buff powder.

Contents

Preparation and handling

Lead azide is prepared by metathesis 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.[2] An alternative synthesis pathway involves dissolving lead acetate in a sodium azide solution.[3][4]

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 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.

See also

References

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. ^ Fedoroff, Basil T.; Henry A. Aaronson, Earl F. Reese, Oliver E. Sheffield, George D. Clift (1960). Encyclopedia of Explosives and Related Items (Vol. 1). US Army Research and Development Command TACOM, ARDEC. 
  3. ^ http://www.lambdasyn.org/synfiles/bleiazid.htm
  4. ^ Verneker, V. R. Pai; Forsyth, Arthur C. (1968). "Mechanism for controlling the reactivity of lead azide". The Journal of Physical Chemistry 72: 111. doi:10.1021/j100847a021. 

External links