3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||81.1184 g/mol|
|Melting point||350 °C (662 °F; 623 K) (in vacuum)|
|41.4 g/100 mL (0 °C)|
50.8 g/100 mL (20 °C)
105.7 g/100 mL (100 °C)
|Solubility||soluble in ethanol|
insoluble in ether
Std enthalpy of
|Occupational safety and health (OHS/OSH):|
|Very Toxic, explosive if strongly heated|
|NFPA 704 (fire diamond)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|27 mg/kg (oral, rat)|
|Sodium azide, copper(II) azide, lead(II) azide, silver azide|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is ?)
It has been found to act as a nitrification inhibitor in soil.
KN3, RbN3, CsN3, and TlN3 adopt the same structures. They crystallize in a tetragonal habit. The azide is bound to eight cations in an eclipsed orientation. The cations are bound to eight terminal N centers.
KN3 is prepared by treating potassium carbonate with hydrazoic acid, which is generated in situ. In contrast, the analogous sodium azide is prepared (industrially) by the "Wislicenus process," which proceeds via the reaction sodium amide with nitrous oxide.
Upon heating or upon irradiation with ultraviolet light, it decomposes into potassium metal and nitrogen gas. The decomposition temperatures of the alkali metal azides are: NaN3 (275 °C), KN3 (355 °C), RbN3 (395 °C), CsN3 (390 °C).
Under pressure potassium azide changes structure to form hezaxine with nitrogen in a ring of six atoms: N2−
6. This is stable at pressures over 20 GPa, but is formed at 45 GPa after heating.