Difference between revisions of "Phosphorus pentoxide"

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| MeltingPt_ref =  
 
| MeltingPt_ref =  
 
| MeltingPt_notes = (sublimes)
 
| MeltingPt_notes = (sublimes)
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| Odor = Odorless
 
| pKa =  
 
| pKa =  
 
| pKb =  
 
| pKb =  
 
| Solubility = Reacts exothermically
 
| Solubility = Reacts exothermically
| SolubleOther = Soluble in [[sulfuric acid]]<br>Insoluble in [[acetic acid]], [[acetone]], [[ammonia]], [[benzene]], [[chloroform]], [[dichloromethane]], [[hexane]], [[toluene]], [[xylene]]<br>Reacts with [[ethanol]], [[methanol]], [[isopropanol]]
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| SolubleOther = Reacts with [[ethanol]], [[methanol]], [[isopropanol]]<br>Soluble in [[sulfuric acid]]<br>Insoluble in [[acetic acid]], [[acetone]], [[ammonia]], [[benzene]], [[chloroform]], [[dichloromethane]], [[hexane]], [[toluene]], [[xylene]]
 
| Solvent =  
 
| Solvent =  
 
| VaporPressure = 1 mmHg at 385 °C
 
| VaporPressure = 1 mmHg at 385 °C
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   }}
 
   }}
 
| Section6 = {{Chembox Hazards
 
| Section6 = {{Chembox Hazards
| AutoignitionPt =  
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| AutoignitionPt = Non-flammable
| ExploLimits =  
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| ExploLimits = Non-flammable
 
| ExternalMSDS = [https://www.fishersci.ca/viewmsds.do?catNo=A244500 FisherScientific]
 
| ExternalMSDS = [https://www.fishersci.ca/viewmsds.do?catNo=A244500 FisherScientific]
| FlashPt =  
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| FlashPt = Non-flammable
 
| LD50 =  
 
| LD50 =  
 
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| LC50 =  
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'''Phosphorus pentoxide''' is a chemical compound with molecular formula '''P<sub>4</sub>O<sub>10</sub>''', more often written as '''P<sub>2</sub>O<sub>5</sub>'''.
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'''Phosphorus pentoxide''' or '''diphosphorus pentoxide''' is an inorganic chemical compound with molecular formula '''P<sub>4</sub>O<sub>10</sub>''', more often written as '''P<sub>2</sub>O<sub>5</sub>'''.
  
 
==Properties==
 
==Properties==
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Phosphorus pentoxide is the anhydride of [[phosphoric acid]]. It will react exothermically with water to yield the said acid.
 
Phosphorus pentoxide is the anhydride of [[phosphoric acid]]. It will react exothermically with water to yield the said acid.
  
It is also a very potent dehydrating agent. It is even capable of robbing water from [[sulfuric acid]], allowing one to distill sulfur trioxide from it.
+
: P<sub>2</sub>O<sub>5</sub> + 3 H<sub>2</sub>O → 2 H<sub>3</sub>PO<sub>4</sub>
 +
 
 +
Phosphorus pentoxide is also a very potent dehydrating agent. It is even capable of robbing water from [[sulfuric acid]], allowing one to distill [[sulfur trioxide]] from it.
 +
 
 +
: P<sub>2</sub>O<sub>5</sub> + H<sub>2</sub>SO<sub>4</sub> → H<sub>3</sub>PO<sub>4</sub> + SO<sub>3</sub>
 +
 
 +
This can be a quick method of preparing SO<sub>3</sub> without the use for contact process.
  
 
===Physical===
 
===Physical===
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==Availability==
 
==Availability==
Phosphorus pentoxide is sold by chemical suppliers.
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Phosphorus pentoxide is sold by chemical suppliers, but is somewhat difficult to acquire. Storing it is also tricky due to its strong hygroscopy, though this can be limited by keeping the compound in a sealed bag.
  
 
==Preparation==
 
==Preparation==
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==Projects==
 
==Projects==
 
*Dry solvents, especially the halogenated ones, which cannot be dried with alkali metals
 
*Dry solvents, especially the halogenated ones, which cannot be dried with alkali metals
*Make pure phosphoric acid
+
*Make pure [[phosphoric acid]]
 
*Convert primary amides into nitriles
 
*Convert primary amides into nitriles
 
*Make [[dinitrogen pentoxide]]
 
*Make [[dinitrogen pentoxide]]
 
*Make [[dichlorine heptoxide]]
 
*Make [[dichlorine heptoxide]]
 +
*Make [[sulfur trioxide]] and [[oleum]]
  
 
==Handling==
 
==Handling==
 
===Safety===
 
===Safety===
It is an extremely powerful desiccant, and contact with bare hand must be avoided. Contact with eyes will result in severe eye damage.
+
Phosphorus pentoxide is an extremely powerful desiccant, and contact with bare hand must be avoided. Contact with eyes will result in severe eye damage, even blindness.
  
 
===Storage===
 
===Storage===
In closed and sealed bottles, away from any moisture. Never store it in aluminium, and galvanised or tin-plated containers. Stainless steel or glass containers are ideal.<ref>http://datasheets.scbt.com/sc-203187.pdf</ref>
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Phosphorus pentoxide must be kept in closed and sealed bottles, away from any moisture. Never store it in aluminium, and galvanized or tin-plated containers! Stainless steel or glass containers are ideal.<ref>http://datasheets.scbt.com/sc-203187.pdf</ref>
  
 
===Disposal===
 
===Disposal===
Phosphorus pentoxide can be neutralized by very slowly adding cold water or a cooled carbonate/bicarbonate solution.  
+
Phosphorus pentoxide can be neutralized by very slowly adding it to crushed ice, followed by addition of a cooled carbonate/bicarbonate solution.  
  
 
==References==
 
==References==
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*[http://www.sciencemadness.org/talk/viewthread.php?tid=1779 P2O5 and P4O10]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=1779 P2O5 and P4O10]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=61801 Recycling Phosphorus Pentoxide]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=61801 Recycling Phosphorus Pentoxide]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=98442 P2O5]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=157615 Is diphosphorus pentoxide hygroscopic?]
  
 
[[Category:Chemical compounds]]
 
[[Category:Chemical compounds]]

Latest revision as of 20:00, 12 September 2021

Phosphorus pentoxide
Names
IUPAC name
Phosphorus pentoxide
Other names
Diphosphorus pentoxide
Phosphorus(V) oxide
Phosphoric anhydride
Tetraphosphorus decaoxide
Tetraphosphorus decoxide
Properties
P2O5
P4O10
Molar mass 283.886 g/mol
Appearance White powder
Odor Odorless
Density 2.39 g/cm3
Melting point 360 °C (680 °F; 633 K) (sublimes)
Boiling point Sublimes
Reacts exothermically
Solubility Reacts with ethanol, methanol, isopropanol
Soluble in sulfuric acid
Insoluble in acetic acid, acetone, ammonia, benzene, chloroform, dichloromethane, hexane, toluene, xylene
Vapor pressure 1 mmHg at 385 °C
Hazards
Safety data sheet FisherScientific
Flash point Non-flammable
Related compounds
Related compounds
Dinitrogen pentoxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Phosphorus pentoxide or diphosphorus pentoxide is an inorganic chemical compound with molecular formula P4O10, more often written as P2O5.

Properties

Chemical

Phosphorus pentoxide is the anhydride of phosphoric acid. It will react exothermically with water to yield the said acid.

P2O5 + 3 H2O → 2 H3PO4

Phosphorus pentoxide is also a very potent dehydrating agent. It is even capable of robbing water from sulfuric acid, allowing one to distill sulfur trioxide from it.

P2O5 + H2SO4 → H3PO4 + SO3

This can be a quick method of preparing SO3 without the use for contact process.

Physical

Phosphorous pentoxide is a white solid, with a pungent odor and strong deliquescent. Its density is 2.30 g/cm3. It boils at 423 °C under atmospheric pressure; if heated more rapidly it can sublimate.

Availability

Phosphorus pentoxide is sold by chemical suppliers, but is somewhat difficult to acquire. Storing it is also tricky due to its strong hygroscopy, though this can be limited by keeping the compound in a sealed bag.

Preparation

Phosphorus pentoxide can be made by burning elemental phosphorus, in a moisture-free environment. One way is to burn phosphorus in a large stainless steel pot with a lid, which has been kept in a dry box. The resulting phosphorus pentoxide fumes from the fire are allowed to settle and cool, then they're scraped off the pot in a dry environment. If you don't need high purity pentoxide, you can do this in open air, but you must move quickly.

Projects

Handling

Safety

Phosphorus pentoxide is an extremely powerful desiccant, and contact with bare hand must be avoided. Contact with eyes will result in severe eye damage, even blindness.

Storage

Phosphorus pentoxide must be kept in closed and sealed bottles, away from any moisture. Never store it in aluminium, and galvanized or tin-plated containers! Stainless steel or glass containers are ideal.[1]

Disposal

Phosphorus pentoxide can be neutralized by very slowly adding it to crushed ice, followed by addition of a cooled carbonate/bicarbonate solution.

References

  1. http://datasheets.scbt.com/sc-203187.pdf

Relevant Sciencemadness threads