PHOSPHOROUS PENTOXIDE

PRODUCT IDENTIFICATION
CAS NO. 1314-56-3

PHOSPHOROUS PENTOXIDE

EINECS NO. 215-236-1
FORMULA P4O10
MOL WT. 283.89

H.S. CODE

 280920

TOXICITY

  

SYNONYMS

 Phosphoric Anhydride; Diphosphorus Pentoxide;
Phosphorus Pentoxide; Phosphoric Pentoxide; Diphosphorus Pentoxide;
DERIVATION Phosphorus( 7723-14-0 ) with excess oxygen

CLASSIFICATION

 

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE

 White, very deliquescent solid wiith irritating odor
MELTING POINT 580 C (under pressure)
BOILING POINT sublimes at 300 C
SPECIFIC GRAVITY 2.39
SOLUBILITY IN WATER Exothermically reacts
pH < 2 (0.1 N aqueous sol. of phosphoric acid)
VAPOR DENSITY 4.9

AUTOIGNITION

 

NFPA RATINGS

 Health: 3 Flammability: 1 Reactivity: 3 Other: water reactive

REFRACTIVE INDEX

 

FLASH POINT Non-combustible
STABILITY Stable under ordinary conditions

GENERAL DESCRIPTION & APPLICATIONS
Phosphorus Pentoxide is a white, flammable, dangerous, and extremely deliquescent solid; specific  gravity 2.39; melting point 580 C (under pressure); sublimes at 300 C. The solid reacts with water violently to produce phosphoric acid. It is prepared by phosphorus reaction with excess oxygen. The crude is then purified by sublimation. Phosphorus pentoxide structure consists of each P atoms linked to three others by oxygen bridges with a terminal oxygen atom. It is used as a strong dehydrating agent, capable even of dehydrating concentrated sulphuric acid into sulphur trioxide. It dehydrates amides to nitriles. End applications include manufacture of phosphorus compounds, purifying sugar, optical glass, heat-insulating glass, medicine, pesticide and surfactant manufacturings.
SALES SPECIFICATION

APPEARANCE

 white to yellow crystalline powder
ASSAY

97.0% min

P2O3 0.5% max
IRON 20ppm max
ARSENIC

30ppm max

Pb

10ppm max

TRANSPORTATION
PACKING 20kgs in Drum
HAZARD CLASS 8
UN NO. 1807
DESCRIPTION OF PHOSPHORUS
Phosphorus is a nonmetallic chemical element in group 15 (nitrogen family, formerly Va) of periodic table; atomic number 15 atomic mass 30.9738; melting point ca 44.1 C (white); boiling point ca 280 C (white); specific gravity 1.82 (white), 2.34 (red), 2.70 (black); valence -3, +3, or +5 ; electronic config. 2-8-5 or 1s 22s 22p 63s 23p 3. The phosphorus molecule is composed of four phosphorus atoms, P4.  Phosphorus exists in a number of allotropic forms [white (alpha and beta), red, black and/or violet] in the same physical state. White phosphorus is a white to yellow waxy substance which ignites spontaneously in air to form white fumes of phosphorus pentoxide and glows without emitting heat. Phosphorus is stored underwater as it is extremely poisonous, insoluble in water (but soluble in carbon disulfide). Commercial production of elemental phosphorus is prepared from phosphorite or phosphate rock (apatite, an impure calcium phosphate mineral) reacting with coke and sand or silica pebblesor at high temperatures in an electric furnace. Calcium silicate is produced as a by-product. White phosphorus is used as a deoxidizing agent in the preparation of steel and phosphor bronze. It is also used in rat poisons and to make smoke screens (by burning) for warfare. When white phosphorus is heated to about 250 C with air absence, it changes into the red phosphorus. Red phosphorus, a dark redish powder or crystal, does not ignite spontaneously  unless heated to 200 C, does not phosphoresce and it is a little less dangerous than white phosphorus. It is used to make matches. Red phosphorus is prepared commercially by heating calcium phosphate with sand and coke in an electric furnace. Black allotrope is obtained industrially by heating at 300 C under pressure with a mercury catalyst. It has a layer structure and is stable. The major use of phosphorus compounds is in fertilizers, mainly as a mixture called superphosphate (calcium hydrogen phosphate), obtained from phosphate minerals by sulfuric acid treatment; and in nitrophosphates. Phosphorus is burned to make phosphorus pentoxide [phosphorus(V) oxide], a white solid used as a chlorinating agent in organic chemistry, as a drying agent and mainly converted to phosphoric acid used to make phosphates for fertilizers, electro chemical polishing and shaping, electroplating, metal cleaning and pickling in metal treatment by reaction with water. Phosphorus is highly reactive. A wide range of compounds is formed for uses in detergents, water softeners, pharmaceuticals, dentifrices, and in many other important applications. It forms metal phosphides and covalently bonded phosphorus(III) and phosphorus(V) compounds. Phosphoric acid can combine with certain alkaline elements to form salts called phosphates.