Hydrazoic acid

Hydrazoic acid
Structure, bonding and dimensions of the hydrogen azide molecule
Hydrazoic acid
Hydrazoic acid
Names
IUPAC name
Hydrogen azide
Other names
Hydrogen azide
Azoimide
Azic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.029.059 Edit this at Wikidata
EC Number
  • 231-965-8
773
UNII
  • InChI=1S/HN3/c1-3-2/h1H checkY
    Key: JUINSXZKUKVTMD-UHFFFAOYSA-N checkY
  • InChI=1/HN3/c1-3-2/h1H
    Key: JUINSXZKUKVTMD-UHFFFAOYAO
  • [N-]=[N+]=N
  • N#[N+][N-H]
Properties
HN3
Molar mass 43.029 g·mol−1
Appearance colorless, highly volatile liquid
Density 1.09 g/cm3
Melting point −80 °C (−112 °F; 193 K)
Boiling point 37 °C (99 °F; 310 K)
highly soluble
Solubility soluble in alkali, alcohol, ether
Acidity (pKa) 4.6 [1]
Conjugate base Azide
Structure
approximately linear
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Highly toxic, explosive, reactive
GHS labelling:
GHS01: ExplosiveGHS07: Exclamation markGHS08: Health hazard
Danger
H200, H319, H335, H370
P201, P202, P260, P261, P264, P270, P271, P280, P281, P304+P340, P305+P351+P338, P307+P311, P312, P321, P337+P313, P372, P373, P380, P401, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
4
0
3
Related compounds
Other cations
 Sodium azide
Lithium azide
Potassium azide
Ammonia
Hydrazine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Hydrazoic acid, also known as hydrogen azide, azic acid or azoimide,[2] is a compound with the chemical formula HN3.[3] It is a colorless, volatile, and explosive liquid at room temperature and pressure. It is a compound of nitrogen and hydrogen, and is therefore a pnictogen hydride. The oxidation state of the nitrogen atoms in hydrazoic acid is fractional and is -1/3.[citation needed] It was first isolated in 1890 by Theodor Curtius.[4] The acid has few applications, but its conjugate base, the azide ion, is useful in specialized processes.

Hydrazoic acid, like its fellow mineral acids, is soluble in water. Undiluted hydrazoic acid is dangerously explosive[5] with a standard enthalpy of formation ΔfHo (l, 298K) = +264 kJ/mol.[6] When dilute, the gas and aqueous solutions (<10%) can be safely prepared but should be used immediately; because of its low boiling point, hydrazoic acid is enriched upon evaporation and condensation such that dilute solutions incapable of explosion can form droplets in the headspace of the container or reactor that are capable of explosion.[7][8]

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. ^ Chisholm, Hugh, ed. (1911). "Azoimide" . Encyclopædia Britannica. Vol. 3 (11th ed.). Cambridge University Press. pp. 82–83. This also contains a detailed description of the contemporaneous production process.
  3. ^ Dictionary of Inorganic and Organometallic Compounds. Chapman & Hall.
  4. ^ Curtius, Theodor (1890). "Ueber Stickstoffwasserstoffsäure (Azoimid) N3H" [On hydrazoic acid (azoimide) N3H]. Berichte der Deutschen Chemischen Gesellschaft. 23 (2): 3023–3033. doi:10.1002/cber.189002302232.
  5. ^ Furman, David; Dubnikova, Faina; van Duin, Adri C. T.; Zeiri, Yehuda; Kosloff, Ronnie (2016-03-10). "Reactive Force Field for Liquid Hydrazoic Acid with Applications to Detonation Chemistry". The Journal of Physical Chemistry C. 120 (9): 4744–4752. Bibcode:2016APS..MARH20013F. doi:10.1021/acs.jpcc.5b10812. ISSN 1932-7447. S2CID 102029987.
  6. ^ Cite error: The named reference InorgChem was invoked but never defined (see the help page).
  7. ^ Gonzalez-Bobes, F. et al Org. Process Res. Dev. 2012, 16, 2051-2057.
  8. ^ Treitler, D. S. et al Org. Process Res. Dev. 2017, 21, 460-467.