Hydrazoic acid
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Hydrazoic acid | |
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General | |
Systematic name | hydrogen azide |
Other names | hydrazoic acid azoimide azidic acid diazoimide hydrogen azide hydronitric acid triazoic acid |
Molecular formula | HN3 |
SMILES | N=N=N |
Molar mass | 43.03 g/mol |
Appearance | Colourless liquid |
CAS number | [ | ]
Properties: | |
Density and phase | ? g/cm3, ? |
Solubility in water | ? g/100 ml (? °C) |
Melting point | −80 °C (193.15 K) |
Boiling point | 37 °C (310.15 K) |
Acidity (pKa) | 4.6 to 4.7 |
Viscosity | ? cP at ?°C |
Structure | |
Molecular shape | Linear |
Dipole moment | ? D |
Hazards | |
MSDS | External MSDS |
Main hazards | Highly toxic, explosive. |
NFPA 704 | |
Flash point | ? °C |
R/S statement | R: R1, R2 S: ? |
RTECS number | ? |
Supplementary data page | |
Structure and properties |
n, εr, etc. |
Thermodynamic data |
Phase behaviour Solid, liquid, gas |
Spectral data | UV, IR, NMR, MS |
Related compounds | |
Other anions | Hydrogen chloride |
Other cations | Sodium azide |
Related acids | Hydrochloric acid hydrocyanic acid |
Related compounds | Hydrazine |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Hydrazoic acid, HN3, is a colorless, volatile, and extremely explosive liquid at room temperature and pressure.
Contents |
[edit] Applications
Hydrazoic acid is used primarily for preservation of stock solutions, and as a reagent.
[edit] History
It was first isolated in 1890 by Theodor Curtius (Berichte, 1890, 23, p. 3023).
[edit] Chemistry
It is soluble in water, and the solution dissolves many metals (e.g. zinc, iron) with liberation of hydrogen and formation of salts (azides, formerly also called azoimides or hydrazoates).
All the salts are explosive and readily interact with the alkyl iodides. In its properties it shows some analogy to the halogen acids, since it forms poorly soluble lead, silver and mercurous salts (in water). The metallic salts all crystallize in the anhydrous form and decompose on heating, leaving a residue of the pure metal. It is a weak acid (pKa 4.6-4.7).
[edit] Production
The acid is formed by acidification of an azide salt, usually sodium azide, or by adding water (which has a lower yield).
The pure acid may be obtained by fractional distillation as a colorless liquid of very unpleasant smell, boiling at ~30 °C., and extremely explosive.
[edit] Toxicity
Hydrazoic acid is volatile and highly poisonous. Its unbearable smell and the violent headache caused by breathing the vapor conspire to make accidental poisoning impossible. The compound acts a non-cumulative poison.
[edit] References
- Dictionary of inorganic and organometallic compounds, Chapman & Hall
[edit] External links
This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.