Dinitrogen pentoxide is the
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...
, also known as nitrogen pentoxide or nitric anhydride. It is one of the binary
nitrogen oxide Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:
Charge-neutral
*Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
*Nitrogen dioxide (), nitrogen(IV) oxide
* Nitrogen trioxide (), or n ...
s, a family of compounds that only contain
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
and
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
. It exists as colourless crystals that melt at 41 °C. Its boiling point is 47 °C, and sublimes slightly above room temperature,
[ yielding a colorless gas.][Peter Steele Connell ]
The Photochemistry of Dinitrogen Pentoxide
'. Ph. D. thesis, Lawrence Berkeley National Laboratory.
Dinitrogen pentoxide is an unstable and potentially dangerous oxidizer that once was used as a reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...
when dissolved in chloroform
Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...
for nitration
In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters between alcohols and ...
s but has largely been superseded by nitronium tetrafluoroborate
Nitronium tetrafluoroborate is an inorganic compound with formula NO2BF4. It is a salt of nitronium cation and tetrafluoroborate anion. It is a colorless crystalline solid, which reacts with water to form the corrosive acids HF and HNO3. As suc ...
().
is a rare example of a compound that adopts two structures depending on the conditions. The solid is a salt, nitronium nitrate, consisting of separate nitronium cations and nitrate anions ; but in the gas phase and under some other conditions it is a covalently-bound molecule.[W. Rogie Angus, Richard W. Jones, and Glyn O. Phillips (1949): "Existence of Nitrosyl Ions (NO+) in Dinitrogen Tetroxide and of Nitronium Ions () in Liquid Dinitrogen Pentoxide". ''Nature'', volume 164, pages 433–434. ]
History
was first reported by Deville in 1840, who prepared it by treating silver nitrate
Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar caustic' ...
() with chlorine
Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...
.
Structure and physical properties
Pure solid is a salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
, consisting of separated linear nitronium ion
The nitronium ion, , is a cation. It is an onium ion because its nitrogen atom has +1 charge, similar to ammonium ion . It is created by the removal of an electron from the paramagnetic nitrogen dioxide molecule , or the protonation of nitric aci ...
s and planar trigonal nitrate
Nitrate is a polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...
anions . Both nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
centers have oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
+5. It crystallizes in the space group ''D'' (''C''6/''mmc'') with ''Z'' = 2, with the anions in the ''D''3''h'' sites and the cations in ''D''3''d'' sites.[
The vapor pressure ''P'' (in atm) as a function of temperature ''T'' (in ]kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and phys ...
), in the range , is well approximated by the formula
:
being about 48 torr at 0 °C, 424 torr at 25 °C, and 760 torr at 32 °C (9 °C below the melting point).[A. H. McDaniel, J. A. Davidson, C. A. Cantrell, R. E. Shetter, and J. G. Calvert (1988): "Enthalpies of formation of dinitrogen pentoxide and the nitrate free radical". ''Journal of Physical Chemistry'', volume 92, issue 14, pages 4172–4175. ]
In the gas phase, or when dissolved in nonpolar solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...
s such as carbon tetrachloride
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...
, the compound exists as covalently-bonded molecules . In the gas phase, theoretical calculations for the minimum-energy configuration indicate that the angle in each wing is about 134° and the angle is about 112°. In that configuration, the two groups are rotated about 35° around the bonds to the central oxygen, away from the plane. The molecule thus has a propeller shape, with one axis of 180° rotational symmetry (''C''2) [S. Parthiban, B. N. Raghunandan, and R.Sumathi (1996): "Structures, energies and vibrational frequencies of dinitrogen pentoxide". ''Journal of Molecular Structure: THEOCHEM'', volume 367, pages 111–118. ]
When gaseous is cooled rapidly ("quenched"), one can obtain the metastable
In chemistry and physics, metastability denotes an intermediate Energy level, energetic state within a dynamical system other than the system's ground state, state of least energy.
A ball resting in a hollow on a slope is a simple example of me ...
molecular form, which exothermically converts to the ionic form above −70 °C.[
Gaseous absorbs ]ultraviolet light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
with dissociation into the free radical
A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing.
Ageing
Ailments of unknown cause
Biogerontology
Biological processes
Causes of death
Cellular processes
Gerontology
Life extension
Metabo ...
s nitrogen dioxide
Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the producti ...
and nitrogen trioxide
Trioxidonitrogen(•) or nitrate radical is an oxide of nitrogen with formula , consisting of three oxygen atoms covalent bond, covalently bound to a nitrogen atom. This highly unstable blue compound has not been isolated in pure form, but can be ...
(uncharged nitrate). The absorption spectrum has a broad band with maximum at wavelength 160 nm.[Bruce A. Osborne, George Marston, L. Kaminski, N. C. Jones, J. M. Gingell, Nigel Mason, Isobel C. Walker, J. Delwiche, and M.-J. Hubin-Franskin (2000): "Vacuum ultraviolet spectrum of dinitrogen pentoxide". ''Journal of Quantitative Spectroscopy and Radiative Transfer'', volume 64, issue 1, pages 67–74. ]
Preparation
A recommended laboratory synthesis entails dehydrating nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...
() with phosphorus(V) oxide
Phosphorus pentoxide is a chemical compound with molecular formula P4 O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydrat ...
:
:
Another laboratory process is the reaction of lithium nitrate
Lithium nitrate is an inorganic compound with the formula LiNO3. It is the lithium salt of nitric acid (an alkali metal nitrate). The salt is deliquescent, absorbing water to form the hydrated form, lithium nitrate trihydrate. Its eutectics are o ...
and bromine pentafluoride
Bromine pentafluoride, Br F5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorinating agent.
BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of BrF5 releases O2 for subsequ ...
, in the ratio exceeding 3:1. The reaction first forms nitryl fluoride
Nitryl fluoride, NO2F, is a colourless gas and strong oxidizing agent, which is used as a fluorinating agent and has been proposed as an oxidiser in rocket propellants (though never flown).
It is a molecular species, not ionic, consistent with it ...
that reacts further with the lithium nitrate:[
:
:
The compound can also be created in the gas phase by reacting ]nitrogen dioxide
Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the producti ...
or with ozone
Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...
:[Francis Yao, Ivan Wilson, and Harold Johnston (1982): "Temperature-dependent ultraviolet absorption spectrum for dinitrogen pentoxide". ''Journal of Physical Chemistry'', volume 86, issue 18, pages 3611–3615. ]
:
However, the product catalyzes
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
the rapid decomposition of ozone:[
:
Dinitrogen pentoxide is also formed when a mixture of oxygen and nitrogen is passed through an electric
discharge.][William W. Wilson and Karl O. Christe (1987): "Dinitrogen Pentoxide. New Synthesis and Laser Raman Spectrum". ''Inorganic Chemistry'', volume 26, pages 1631–1633. ] Another route is the reactions of Phosphoryl chloride
Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosp ...
or nitryl chloride
Nitryl chloride is a volatile inorganic compound with formula ClNO2. At standard conditions it is a gas.
Formation
Nitryl chloride can be formed in the reaction of dinitrogen pentoxide with chlorides or hydrogen chloride:
:N2O5 + 2HCl → 2ClNO2 ...
with silver nitrate
Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar caustic' ...
[
]
Reactions
Dinitrogen pentoxide reacts with water (hydrolyses
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolysis ...
) to produce nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...
. Thus, dinitrogen pentoxide is the anhydride
An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the pa ...
of nitric acid:[
:
Solutions of dinitrogen pentoxide in nitric acid can be seen as nitric acid with more than 100% concentration. The phase diagram of the system − shows the well-known negative ]azeotrope
An azeotrope () or a constant heating point mixture is a mixture of two or more liquids whose proportions cannot be altered or changed by simple distillation.Moore, Walter J. ''Physical Chemistry'', 3rd e Prentice-Hall 1962, pp. 140–142 This ...
at 60% (that is, 70% ), a positive azeotrope at 85.7% (100% ), and another negative one at 87.5% ("102% ").[L. Lloyd and P. A. H. Wyatt (1955): "The vapour pressures of nitric acid solutions. Part I. New azeotropes in the water–dinitrogen pentoxide system". ''Journal of the Chemical Society (Resumed)'', volume 1955, pages 2248–2252.]
The reaction with hydrogen chloride
The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...
also gives nitric acid and nitryl chloride
Nitryl chloride is a volatile inorganic compound with formula ClNO2. At standard conditions it is a gas.
Formation
Nitryl chloride can be formed in the reaction of dinitrogen pentoxide with chlorides or hydrogen chloride:
:N2O5 + 2HCl → 2ClNO2 ...
:[Robert A. Wilkins Jr. and I. C. Hisatsune (1976): "The Reaction of Dinitrogen Pentoxide with Hydrogen Chloride". ''Industrial & Engineering Chemistry Fundamentals'', volume 15, issue 4, pages 246–248. ]
:
Dinitrogen pentoxide eventually decomposes at room temperature into and .[ Decomposition is negligible if the solid is kept at 0 °C, in suitably inert containers.][
Dinitrogen pentoxide reacts with ]ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...
to give several products, including nitrous oxide
Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has a ...
, ammonium nitrate
Ammonium nitrate is a chemical compound with the chemical formula . It is a white crystalline salt consisting of ions of ammonium and nitrate. It is highly soluble in water and hygroscopic as a solid, although it does not form hydrates. It is ...
, nitramide
Nitramide is a chemical compound with the molecular formula H2NNO2. Organyl derivatives of nitramide, RNHNO2 are termed nitroamines, and are widely used as explosives: examples include RDX and HMX. It is an isomer of hyponitrous acid.
Structure ...
and ammonium dinitramide
Ammonium dinitramide (ADN) is the ammonium salt of dinitraminic acid. ADN decomposes under heat to leave only nitrogen, oxygen, and water. The ions are the ammonium ion NH4+ and the dinitramide N(NO2)2−.
It makes an excellent solid rocket ox ...
, depending on reaction conditions.[C. Frenck and W. Weisweiler (2002): "Modeling the Reactions Between Ammonia and Dinitrogen Pentoxide to Synthesize Ammonium Dinitramide (ADN)". ''Chemical Engineering & Technology'', volume 25, issue 2, pages 123–128. ]
Decomposition of dinitrogen pentoxide at high temperatures
Dinitrogen pentoxide between high temperatures of , is decomposed in two successive stoichiometric steps:
:
:
In the shock wave, has decomposed stoichiometrically into nitrogen dioxide
Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the producti ...
and oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
. At temperatures of 600 K and higher, nitrogen dioxide is unstable with respect to nitrogen oxide Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:
Charge-neutral
*Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
*Nitrogen dioxide (), nitrogen(IV) oxide
* Nitrogen trioxide (), or n ...
and oxygen. The thermal decomposition of 0.1 mM nitrogen dioxide at 1000 K is known to require about two seconds.[Schott, G., & Davidson, N. (1958). Shock Waves in Chemical Kinetics: The Decomposition of N2O5 at High Temperatures. Journal of the American Chemical Society, 80(8), 1841–1853. ]
Decomposition of dinitrogen pentoxide in carbon tetrachloride at 30 °C
Apart from the decomposition of at high temperatures, it can also be decomposed in carbon tetrachloride
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...
at .[J.,Jaime, R. (2008)]
Determinación de orden de reacción haciendo uso de integrales definidas
Universidad Nacional Autónoma de Nicaragua, Managua.
Both and are soluble in and remain in solution while oxygen is insoluble and escapes. The volume of the oxygen formed in the reaction can be measured in a gas burette. After this step we can proceed with the decomposition, measuring the quantity of that is produced over time because the only form to obtain is with the decomposition.
The equation below refers to the decomposition of in :
:
And this reaction follows the first order rate law
In chemistry, the rate law or rate equation for a reaction is an equation that links the initial or forward reaction rate with the concentrations or pressures of the reactants and constant parameters (normally rate coefficients and partial reactio ...
that says:
: