- Hydrazoic acid
Chembox new
Name = Hydrazoic acid
ImageFile = Hydrogen-azide-2D-dimensions.png
ImageName = Structure, bonding and dimensions of the hydrogen azide molecule
ImageFile1 = Hydrogen-azide-3D-vdW.png
ImageName1 = Hydrazoic acid
IUPACName = hydrogen azide
Name = Properties:
Section1 = Chembox Identifiers
SMILES = N=N=N
CASNo = 7782-79-8
RTECS =
Section2 = Chembox Properties
Formula = HN3
MolarMass = 43.03 g/mol
Solubility =
MeltingPt = −80 °C (193.15 K)
BoilingPt = 37 °C (310.15 K)
pKa = 4.6 to 4.7
Viscosity =
Section3 = Chembox Structure
MolShape = Linear
Dipole =
Section7 = Chembox Hazards
ExternalMSDS =
MainHazards = Highly toxic, explosive.
FlashPt =
RPhrases = R1, R2
SPhrases =
Section8 = Chembox Related
OtherAnions =Hydrogen chloride
OtherCations =Sodium azide
Function =acid s
OtherFunctn =Hydrochloric acid hydrocyanic acid
OtherCpds =Hydrazine Hydrazoic acid, HN3, is a colorless, volatile, and extremely explosive liquid at room temperature and pressure.
Applications
Hydrazoic acid is used primarily for preservation of stock solutions, and as a reagent.
History
It was first isolated in
1890 byTheodor Curtius ("Berichte", 1890, 23, p. 3023).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 iodide s. In its properties hydrazoic acid 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).Production
The acid is usually formed by acidification of an azide salt like
sodium azide . Normally solutions of sodium azide in water contain trace quantities of hydrazoic acid in equilibrium with the azide salt, but introduction of a stronger acid can convert the primary species in solution to hydrazoic acid. The pure acid may be subsequently obtained by fractional distillation as an extremely explosive colorless liquid with an unpleasant smell.Toxicity
Hydrazoic acid is volatile and highly toxic. It has a pungent smell and its vapor can cause violent headaches. The compound acts as a non-cumulative poison.
References
* Dictionary of inorganic and organometallic compounds, Chapman & Hall
External links
* [http://www.osha.gov/dts/chemicalsampling/data/CH_245950.html OSHA: Hydrazoic Acid]
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