Names | |||
---|---|---|---|
IUPAC name Potassium azide | |||
Identifiers | |||
3D model (JSmol) | |||
ECHA InfoCard | 100.039.997 | ||
PubChem CID | |||
UNII | |||
CompTox Dashboard (EPA) | |||
| |||
| |||
Properties | |||
KN3 | |||
Molar mass | 81.1184 g/mol | ||
Appearance | Colorless crystals [1] | ||
Density | 2.038 g/cm3 [1] | ||
Melting point | 350 °C (662 °F; 623 K) (in vacuum) [1] | ||
Boiling point | decomposes | ||
41.4 g/100 mL (0 °C) 50.8 g/100 mL (20 °C) 105.7 g/100 mL (100 °C) | |||
Solubility | 0.1375 g/100 g in ethanol (16°C) [2] insoluble in ether | ||
Thermochemistry | |||
Std enthalpy of formation (ΔfH⦵298) | -1.7 kJ/mol | ||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards | Very Toxic, explosive if strongly heated | ||
NFPA 704 (fire diamond) | |||
Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) | 27 mg/kg (oral, rat) [3] | ||
Related compounds | |||
Other cations | 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). |
Potassium azide is the inorganic compound having the formula KN3. It is a white, water-soluble salt. It is used as a reagent in the laboratory.
It has been found to act as a nitrification inhibitor in soil. [4]
KN3, RbN3, CsN3, and TlN3 adopt the same structures. They crystallize in a tetragonal habit. [5] The azide is bound to eight cations in an eclipsed orientation. The cations are bound to eight terminal N centers. [6]
KN3 is prepared by treating potassium carbonate with hydrazoic acid, which is generated in situ. [7] In contrast, the analogous sodium azide is prepared (industrially) by the "Wislicenus process," which proceeds via the reaction sodium amide with nitrous oxide. [8]
Upon heating or upon irradiation with ultraviolet light, it decomposes into potassium metal and nitrogen gas. [9] The decomposition temperatures of the alkali metal azides are: NaN3 (275 °C), KN3 (355 °C), RbN3 (395 °C), CsN3 (390 °C). [10]
Under high pressures and high temperatures, potassium azide was found to transform into the K2N6 and K9N56 compounds, both containing hexazine rings: N2−
6 and N64-, respectively. [11] [12]
Like sodium azide, potassium azide is very toxic. The threshold limit value of the related sodium azide is 0.07 ppm. The toxicity of azides arise from their ability to inhibit cytochrome c oxidase. [8]
The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. This family of elements is also known as the lithium family after its leading element.
Caesium is a chemical element; it has symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C, which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. It is pyrophoric and reacts with water even at −116 °C (−177 °F). It is the least electronegative element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite. Caesium-137, a fission product, is extracted from waste produced by nuclear reactors. It has the largest atomic radius of all elements whose radii have been measured or calculated, at about 260 picometers.
In chemistry, azide is a linear, polyatomic anion with the formula N−3 and structure −N=N+=N−. It is the conjugate base of hydrazoic acid HN3. Organic azides are organic compounds with the formula RN3, containing the azide functional group. The dominant application of azides is as a propellant in air bags.
Cuprates are a class of compounds that contain copper (Cu) atom(s) in an anion. They can be broadly categorized into two main types:
Sodium azide is an inorganic compound with the formula NaN3. This colorless salt is the gas-forming component in some car airbag systems. It is used for the preparation of other azide compounds. It is an ionic substance, is highly soluble in water, and is acutely poisonous.
Hydrazoic acid, also known as hydrogen azide, azic acid or azoimide, is a compound with the chemical formula HN3. 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. It was first isolated in 1890 by Theodor Curtius. The acid has few applications, but its conjugate base, the azide ion, is useful in specialized processes.
Sodium oxide is a chemical compound with the formula Na2O. It is used in ceramics and glasses. It is a white solid but the compound is rarely encountered. Instead "sodium oxide" is used to describe components of various materials such as glasses and fertilizers which contain oxides that include sodium and other elements.
Potassium cyanate is an inorganic compound with the formula KOCN. It is a colourless solid. It is used to prepare many other compounds including useful herbicide. Worldwide production of the potassium and sodium salts was 20,000 tons in 2006.
Silver azide is the chemical compound with the formula AgN3. It is a silver(I) salt of hydrazoic acid. It forms a colorless crystals. Like most azides, it is a primary explosive.
The chemical element nitrogen is one of the most abundant elements in the universe and can form many compounds. It can take several oxidation states; but the most common oxidation states are -3 and +3. Nitrogen can form nitride and nitrate ions. It also forms a part of nitric acid and nitrate salts. Nitrogen compounds also have an important role in organic chemistry, as nitrogen is part of proteins, amino acids and adenosine triphosphate.
Hexazine is a hypothetical allotrope of nitrogen composed of 6 nitrogen atoms arranged in a ring-like structure analogous to that of benzene. As a neutrally charged species, it would be the final member of the azabenzene (azine) series, in which all of the methine groups of the benzene molecule have been replaced with nitrogen atoms. The two last members of this series, hexazine and pentazine, have not been observed, although all other members of the azine series have.
Barium azide is an inorganic azide with the formula Ba(N3)2. It is a barium salt of hydrazoic acid. Like most azides, it is explosive. It is less sensitive to mechanical shock than lead azide.
Silicon tetraazide is a thermally unstable binary compound of silicon and nitrogen with a nitrogen content of 85.7%. This high-energy compound combusts spontaneously and can only be studied in a solution. A further coordination to a six-fold coordinated structure such as a hexaazidosilicate ion [Si(N3)6]2− or as an adduct with bicationic ligands Si(N3)4·L2 will result in relatively stable, crystalline solids that can be handled at room temperature.
Fluorine azide or triazadienyl fluoride is a yellow green gas composed of nitrogen and fluorine with formula FN3. Its properties resemble those of ClN3, BrN3, and IN3. The bond between the fluorine atom and the nitrogen is very weak, leading to this substance being very unstable and prone to explosion. Calculations show the F–N–N angle to be around 102° with a straight line of 3 nitrogen atoms.
Rubidium azide is an inorganic compound with the formula RbN3. It is the rubidium salt of the hydrazoic acid HN3. Like most azides, it is explosive.
A carbonate fluoride, fluoride carbonate, fluorocarbonate or fluocarbonate is a double salt containing both carbonate and fluoride. The salts are usually insoluble in water, and can have more than one kind of metal cation to make more complex compounds. Rare-earth fluorocarbonates are particularly important as ore minerals for the light rare-earth elements lanthanum, cerium and neodymium. Bastnäsite is the most important source of these elements. Other artificial compounds are under investigation as non-linear optical materials and for transparency in the ultraviolet, with effects over a dozen times greater than Potassium dideuterium phosphate.
Caesium azide or cesium azide is an inorganic compound of caesium and nitrogen. It is a salt of azide with the formula CsN3.
Boron triazide, also known as triazidoborane, is a thermally unstable compound of boron and nitrogen with a nitrogen content of 92.1 %. Formally, it is the triazido derivative of borane and is a covalent inorganic azide. The high-energy compound, which has the propensity to undergo spontaneous explosive decomposition, was first described in 1954 by Egon Wiberg and Horst Michaud of the University of Munich.
Pentazenium tetraazidoborate is an extremely unstable chemical compound with the formula N5[B(N3)4]. It is a white solid that violently explodes at room temperature. This compound has a 95.7% nitrogen content which is the second highest known of a chemical compound, exceeding even that of ammonium azide (93.3%) and 1-diazidocarbamoyl-5-azidotetrazole (89.1%), being surpassed only by hydrazoic acid (97.7%).