Lithium azide has only moderate explosive properties. Decomposition of lithium azide only forms lithium nitride and nitrogen. It can survive hammer
blows without detonation
Sodium azide is not itself an explosive. The main reason for this is rather simple- the decomposition proceeds according to the following equation:
2 NaN3 --> 2 Na + 3 N2
The reduction of sodium ions to elemental sodium is not particularly favorable, and this is one of the main reasons sodium azide is not explosive.
Sodium nitride does not form because Na3N is not very stable (sodium nitride decomposes into its elements at only 87 °C ).
Calcium azide begins to thermally decompose above 110 °C, and explodes at 158°, it is more explosive than either strontium or barium azide.
Barium azide is a sensitive explosive, with a drop height value of 10cm. It appears to be relatively insensitive to impact but highly sensitive to
friction.
H. Ficheroulle, Mem. des Poudres. 33, 7 (1956)
The temperature at which barium azide explodes is apparently highly variable, values have been reported between 152° to 221°C.
The enthalpy of formation for barium azide from its elements is actually slightly negative, -5.3 kcal/mole. The formation of barium nitride is very
favorable, the compound having an enthalpy of formation of -89.9 kcal/mole. "Nitrogen Burning of Metals", G. Petrov, Combustion, Explosion, and
Shock Waves, Volume 11, Number 3, 309-312
The decomposition products from the explosion of barium azide leave behind a significant quantity of metallic barium, whereas the explosion of calcium
azide leaves only calcium nitride.
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