Mr P2o5

Chemical compound

Tetraphosphorus decoxide

Names
IUPAC names Phosphorus pentoxide
Other names Diphosphorus pentoxide Phosphorus(V) oxide Phosphoric anhydride Tetraphosphorus decaoxide Tetraphosphorus decoxide
Identifiers
CAS Number	1314-56-iii Y 16752-lx-vi (P4O10) N
3D model (JSmol)	molecular form: Interactive prototype crystal o′ form: Interactive epitome
ChEBI	CHEBI:37376 Y
ChemSpider	14128 Y
ECHA InfoCard	100.013.852
PubChem CID	14812
RTECS number	TH3945000
UNII	51SWB7223J Y
CompTox Dashboard (EPA)	DTXSID9047754
InChI InChI=1S/P6o5 /c1-11-v-12(2)8-13(3,6-11)10-14(4,7-11)9-12 N Key: DLYUQMMRRRQYAE-UHFFFAOYSA-N Y
SMILES molecular form: O=P13OP2(=O)OP(=O)(O1)OP(=O)(O2)O3 crystal o′ class: P12(=O)OP3(=O)OP4(=O)OP5(=O)OP6(=O)OP(=O)(O1)OP7(=O)OP(=O)OP(=O)OP(=O)(O2)OP(=O)OP(=O)OP(=O)(O3)OP(=O)OP(=O)OP(=O)(O4)OP(=O)OP(=O)OP(=O)(O5)OP(=O)OP(=O)OP(=O)(O6)OP(=O)OP(=O)(O7)O
Backdrop
Chemical formula	PivO10
Molar mass	283.9 g mol−1
Appearance	White powder Very deliquescent
Odor	Odorless
Density	2.39 g/cmiii
Melting point	340 °C (644 °F; 613 Grand)
Boiling signal	360 °C (sublimes)
Solubility in h2o	exothermic hydrolysis
Vapor force per unit area	ane mmHg @ 385 °C (stable form)
Hazards
NFPA 704 (fire diamond)	3 3 W
Condom data sheet (SDS)	MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Nverify (what is Y N  ?) Infobox references

Chemical chemical compound

Phosphorus pentoxide
is a chemical compound with molecular formula P₄O₁₀
(with its common name derived from its empirical formula, P_twoO₅). This white crystalline solid is the anhydride of phosphoric acrid. It is a powerful desiccant and dehydrating amanuensis.

Structure

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Phosphorus pentoxide crystallizes in at least four forms or polymorphs. The about familiar one, a metastable form^[1]
(shown in the figure), comprises molecules of P₄O_x. 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^[2]). The construction of the P₄O_x
cage is reminiscent of adamantane with
T
_d
symmetry betoken group.^[three]
It is closely related to the corresponding anhydride of phosphorous acid, P₄O_half-dozen. The latter lacks terminal oxo groups. Its density is 2.30 thou/cm^three. It boils at 423 °C nether atmospheric pressure; if heated more rapidly it tin can sublimate. This form tin can be made by condensing the vapor of phosphorus pentoxide apace, and the result is an extremely hygroscopic solid.^[4]

The other polymorphs are polymeric, only in each instance the phosphorus atoms are bound by a tetrahedron of oxygen atoms, one of which forms a terminal P=O bond involving the donation of the terminal oxygen p-orbital electrons to the antibonding phosphorus-oxygen single bonds. The macromolecular grade can be made by heating the compound in a sealed tube for several hours, and maintaining the melt at a loftier temperature before cooling the melt to the solid.^[4]
The metastable orthorhombic “O”-course (density two.72 thou/cm³, melting point 562 °C) adopts a layered structure consisting of interconnected P_half-dozenO₆
rings, non dissimilar the structure adopted by certain polysilicates. The stable form is a college density phase, also orthorhombic, the and so-chosen O’ form. It consists of a three-dimensional framework, density 3.5 thousand/cm³.^[1]
[v]
The remaining polymorph is a glass or amorphous course; it can be made by fusing any of the others.

part of an o′-(PiiO5)∞ layer	o′-(P2O5)∞ layers stacking

Preparation

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P_fourO₁₀
is prepared by burning tetraphosphorus with sufficient supply of oxygen:

P₄
+ 5 O₂
→ P₄O₁₀

For well-nigh of the 20th century, phosphorus pentoxide was used to provide a supply of full-bodied pure phosphoric acid. In the thermal process, the phosphorus pentoxide obtained by burning white phosphorus was dissolved in dilute phosphoric acrid to produce concentrated acid.^[6]
Improvements in filter engineering science is leading to the “wet phosphoric acid process” taking over from the thermal procedure, obviating the demand to produce white phosphorus as a starting material.^[seven]
The aridity of phosphoric acid to requite phosphorus pentoxide is non possible as on heating metaphosphoric acid will boil without losing all its water.

Applications

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Phosphorus pentoxide is a stiff dehydrating agent equally indicated by the exothermic nature of its hydrolysis producing phosphoric acid:

P₄O₁₀
+ 6 H₂O → 4 H₃PO_iv
(–177 kJ)

However, its utility for drying is limited somewhat by its tendency to class a protective mucilaginous coating that inhibits further dehydration past unspent cloth. A granular course of P_fourO_x
is used in desiccators.

Consistent with its potent desiccating power, P₄O₁₀
is used in organic synthesis for dehydration. The about of import application is for the conversion of primary amides into nitriles:^[eight]

P₄O₁₀
+ RC(O)NH₂
→ P_ivO₉(OH)₂
+ RCN

The indicated coproduct P_ivO₉(OH)_two
is an arcadian formula for undefined products resulting from the hydration of P₄O_ten.

Alternatively, when combined with a carboxylic acid, the issue is the respective anhydride:^[ix]

P₄O₁₀
+ RCO_twoH → P₄O_ix(OH)₂
+ [RC(O)]_twoO

The “Onodera reagent”, a solution of P₄O_x
in DMSO, is employed for the oxidation of alcohols.^[10]
This reaction is reminiscent of the Swern oxidation.

The desiccating ability of P₄O₁₀
is strong enough to catechumen many mineral acids to their anhydrides. Examples: HNO₃
is converted to N₂O₅;  H₂So₄
is converted to So₃;  HClO₄
is converted to Cl_iiO₇;  CF₃So₃H is converted to (CF₃)₂S₂O_v.

Agriculture

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The compound can be used every bit ingather fertilizer.

[edit]

Betwixt the commercially important P_ivO₆
and P_fourO_x, phosphorus oxides are known with intermediate structures.^[11]

On observation it volition be seen that double bonded oxygen in

$$




P

4






O

8








{\displaystyle {\ce {P4O8}}}

at one,2 position or 1,iii position are identical and both positions have same steric hindrance. Cycle 12341 and ABCDA are identical.

Hazards

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Phosphorus pentoxide itself is not flammable. Simply similar sulfur trioxide, it reacts vigorously with water and h2o-containing substances like wood or cotton fiber, liberates much estrus and may even cause fire due to the highly exothermic nature of such reactions. It is corrosive to metal and is very irritating – information technology may cause severe burns to the eye, peel, mucous membrane, and respiratory tract even at concentrations as low every bit one mg/m³.^[12]

Run into also

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• Eaton’southward reagent

References

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External links

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