Phosphorus pentoxide

Phosphorus pentoxide


Other names	Phosphorus(V) oxide Phosphoric anhydride
Identifiers
CAS number	[1314-56-3] (P₂O₅) [16752-60-6] (P₄O₁₀)
Properties
Molecular formula	O₁₀P₄
Molar mass	283. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 889 g mol⁻¹
Appearance	white powder very deliquescent pungent odour
Density	2. Hygroscopy is the ability of a substance to attract Water Molecules from the surrounding environment through either absorption or Adsorption The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 39 g cm⁻³, solid
Melting point	569 °C
Boiling point	sublimes at 360 °C
Solubility in water	exothermic hydrolysis
Vapor pressure	1 mmHg @ 384 °C
Hazards
EU classification	not listed
NFPA 704	1 3 3 W
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Phosphorus pentoxide is a chemical compound with formula P₂O₅. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. In Thermodynamics, the word exothermic "outside heating" describes a process or reaction that releases Energy usually in the form of Heat, but Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. Phosphorus, (ˈfɒsfərəs is the Chemical element that has the symbol P and Atomic number 15 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the This white crystalline solid is the anhydride of phosphoric acid. In Chemistry, an anhydride is a compound that can be considered as derived from another compound by subtracting the molecules of water. Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula It is a powerful desiccant. A Desiccant is a Hygroscopic substance that induces or sustains a state of dryness ( Desiccation) in its local vicinity in a moderately-well sealed container

1 Structure
2 Preparation
3 Applications
4 Related phosphorus oxides
5 Fiction
6 References
7 See also
8 External links

Structure

P₂O₅ crystallizes in at least four forms or polymorphs. Polymorphism in Materials science is the ability of a solid material to exist in more than one form or Crystal structure The most familiar one, shown in the figure, comprises molecules of P₄O₁₀. Weak van der Waals forces hold these molecules together in a hexagonal lattice (However, in spite of the high symmetry of the molecules, the crystal packing is not a close packing^[1]). The structure of the P₄O₁₀ cage is reminiscent of adamantane with T_d symmetry point group. Adamantane (tricyclodecane is a colourless crystalline compound with a Camphor -like odour Group theory is a mathematical discipline the part of Abstract algebra that studies the Algebraic structures known as groups. ^[2] It is closely related to the corresponding anhydride of phosphorous acid, P₄O₆. Phosphorous acid is the compound described by the formula H3PO3 The latter lacks terminal oxo groups. Its density is 2. 30 g/cm³. It boils at 423 °C under atmospheric pressure; if heated more rapidly it can sublime.

The other polymorphs are polymeric, but in each case the phosphorus atoms are bound by a tetrahedron of oxygen atoms, one of which forms a terminal P=O bond. The O-form (density 3. 05 g/cm³, m. p. 580 °C), adopts a layered structure consisting of interconnected P₆O₆ rings, not unlike the structure adopted by certain polysilicates. For the Artificial intelligence Androids of the 1990s Science fiction series Space Above and Beyond, see Silicate (AI A lower density phase, the so-called O' form, consists of a 3-dimensional framework is also known, density 2. 72 g/cm³. The remaining polymorph is a glass or amorphous form; it can be made by fusing any of the others. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many

Preparation

P₂O₅ is prepared by burning elemental phosphorus with sufficient supply of air :

P₄ + 5 O₂ → 2 P₂O₅

For most of the 20th century, phosphorus pentoxide was used to provide a supply of concentrated pure phosphoric acid. Phosphorus, (ˈfɒsfərəs is the Chemical element that has the symbol P and Atomic number 15 The twentieth century of the Common Era began on Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula In the thermal process, the phosphorus pentoxide obtained by burning white phosphorus was dissolved in dilute phosphoric acid to produce concentrated acid. Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula ^[3] Improvements in filter technology is leading to the "wet phosphoric acid process" taking over from the thermal process, obviating the need to produce white phosphorus as a starting material. ^[4]

Applications

Phosphorus pentoxide is a potent dehydrating agent as indicated by the exothermic nature of its hydrolysis:

P₄O₁₀ (am) + 6H₂O (lq) → 4H₃PO₄ (c) (-177 kJ)

However, its utility for drying is limited somewhat by its tendency to form a protective viscous coating that inhibits further dehydration by unspent material. In Chemistry, a dehydration reaction is usually defined as a chemical reaction that involves the loss of water from the reacting molecule The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity A granular form of P₄O₁₀ is used in desiccators. Desiccators are sealable enclosures containing Desiccants used for preserving Moisture -sensitive items

Consistent with its strong desiccating power, P₄O₁₀ is used in organic synthesis for dehydration. Organic synthesis is a special branch of Chemical synthesis and is concerned with the construction of Organic compounds via Organic reactions Organic The most important application is for the conversion of amides into nitriles:^[5]

P₄O₁₀ + RC(O)NH₂ → P₄O₉(OH)₂ + RCN

The indicated coproduct P₄O₉(OH)₂ is an idealized formula for undefined products resulting from the hydration of P₄O₁₀. In Chemistry, an amide is one of three kinds of Compounds (sometimes called acid amide the organic Functional group characterized A nitrile is any Organic compound which has a - C ≡ N Functional group.

Apparently, when combined with a carboxylic acid, the result is the corresponding anhydride:

P₄O₁₀ + RCO₂H → P₄O₉(OH)₂ + [RC(O)]₂O

The "Onodera reagent", a solution of P₄O₁₀ in DMSO, is employed for the oxidation of alcohols. Carboxylic acids are Organic acids characterized by the presence of a Carboxyl group, which has the formula -C(=OOH usually written -COOH or -CO2H In Chemistry, an anhydride is a compound that can be considered as derived from another compound by subtracting the molecules of water. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon ^[6] This reaction is reminiscent of the Swern oxidation. The Swern oxidation, named after Daniel Swern, is a Chemical reaction whereby a primary or secondary Alcohol is oxidized to an Aldehyde

The desiccating power of P₄O₁₀ is strong enough to convert many mineral acids to their anhydrides. Examples: HNO₃ is converted to N₂O₅; H₂SO₄ is converted to SO₃; HClO₄ is converted to Cl₂O₇. Nitric acid ( H[[nitrate NO3]] also known as Aqua fortis and spirit of nitre, is a highly corrosive and Dinitrogen pentoxide is the Chemical compound with the formula N2O5 Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Sulfur trioxide (also spelled sulphur trioxide) is the chemical compound with the formula SO3 Perchloric acid, HClO4 is an Oxoacid of Chlorine and is a colorless liquid soluble in water. Dichlorine heptoxide is the Chemical compound with the formula Cl2O7

Related phosphorus oxides

Between the commercially important P₄O₆ and P₄O₁₀, phosphorus oxides are known with intermediate structures. Phosphorus trioxide is the Chemical compound with the formula P4O6 ^[7]

Fiction

In Anthony Burgess' The Wanting Seed, phosphorus pentoxide is a highly prized compound. Anthony Burgess (February 25 1917 — November 22 1993 was an English Novelist, Critic, Composer, Librettist, Poet The Wanting Seed is a Dystopian Novel by the English author Anthony Burgess, written in 1962. A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass.

In Detective Comics #825, Batman notices that phosphorus pentoxide was at the scene of a fire, indicating that the villain Dr. Phosphorus was involved. Detective Comics is an American comic book published monthly by DC Comics since 1937 best-known for introducing the iconic Superhero Batman Batman (originally referred to as the Bat-Man and still referred to at times as the Batman) is a fictional Comic book Superhero co-created Doctor Phosphorus (real name Dr Alex Sartorius) is a Fictional character who has appeared in various Comic book series published by DC Comics

In Aldous Huxley's Point Counter Point, Lord Edward bemoans societal loss of phosphorous pentoxide to his assistant Illidge. Aldous Leonard Huxley (26 July 1894 &ndash 22 November 1963 was an English writer and one of the most prominent members of the famous Huxley family. Point Counter Point, published in 1928 was Aldous Huxley 's fourth novel

In Aldous Huxley's Brave New World, Henry Foster tells Lenina about the recovery of phosphorus pentoxide. Aldous Leonard Huxley (26 July 1894 &ndash 22 November 1963 was an English writer and one of the most prominent members of the famous Huxley family. Brave New World is a 1932 Novel by Aldous Huxley. Set in the London of AD 2540 (632 A

References

^ Cruickshank, D. W. J. "Refinements of Structures Containing Bonds between Si, P, S or Cl and O or N: V. P₄O₁₀" Acta Cryst. 1964, volume 17, pages 677-9.
^ D. E. C. Corbridge "Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology" 5th Edition Elsevier: Amsterdam. ISBN 0-444-89307-5.
^ Threlfall, Richard E. , (1951). The story of 100 years of Phosphorus Making: 1851 - 1951. Oldbury: Albright & Wilson Ltd
^ Podger, Hugh (2002). Albright & Wilson: The Last 50 Years. Studley: Brewin Books. ISBN 1-85858-223-7
^ Meier, M. S. "Phosphorus(V) Oxide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10. 1002/047084289.
^ Tidwell, T. T. "Dimethyl Sulfoxide–Phosphorus Pentoxide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10. 1002/047084289.
^ Luer, B. ; Jansen, M. "Crystal Structure Refinement of Tetraphosphorus Nonaoxide, P₄O₉" Zeitschrift fur Kristallographie 1991, volume 197, pages 247-8.

External links

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