ChemicalBook--->CAS DataBase List--->7446-11-9

7446-11-9

7446-11-9 Structure

7446-11-9 Structure
IdentificationMore
[Name]

Sulfur trioxide
[CAS]

7446-11-9
[Synonyms]

SULFAN(R)
SULFURIC ANHYDRIDE
SULFUR TRIOXIDE
SULPHUR TRIOXIDE
SO3
Sulfan
Sulfur oxide (SO3)
Sulfur trioxide, stabilized
Sulfuric oxide
Sulfuricacidanhydride
sulfuricoxide
sulfurtrioxide,stabilized
Liquid Sulfur Trioxide
Sulfur trioxide, packaged in ampules, stabilized, 99%
Schwefeltrioxid
sulfur trioxide,inhibited
Sulfur trioxide,liquid
Oxosulfane dioxide
SULFUR TRIOXIDE, 99%, PACKAGED IN AMPULES, STABILIZED
Sulfur(VI) trioxide
[EINECS(EC#)]

231-197-3
[Molecular Formula]

O3S
[MDL Number]

MFCD00011452
[Molecular Weight]

80.06
[MOL File]

7446-11-9.mol
Chemical PropertiesBack Directory
[Appearance]

Sulfur trioxide is a crystalline solid which has 3 forms: alpha-, beta-, and gamma-; and can also exist as a gas or liquid.
[Melting point ]

16.8 °C(lit.)
[Boiling point ]

44.8 °C
[density ]

1.97 g/mL at 25 °C(lit.)
[vapor density ]

2.8 (vs air)
[vapor pressure ]

280 mm Hg ( 25 °C)
[storage temp. ]

Indoors
[solubility ]

reacts with H2O
[form ]

colorless liquid
[color ]

white needles
[Stability:]

Stable. Incompatible with organic materials, finely powdered metals, bases, water, cyanides and a wide variety of other chemicals. Reacts violently with water, oxygen and other chemicals-read a full data sheet before use.
[Water Solubility ]

reacts violently
[Merck ]

13,9069
[Dielectric constant]

3.1(18℃)
[Uses]

Sulfonation of organic compounds, especially nonionic detergents, solar energy collectors. It is usually generated in the plant where it is to be used.
[CAS DataBase Reference]

7446-11-9(CAS DataBase Reference)
[NIST Chemistry Reference]

Sulfur trioxide(7446-11-9)
[EPA Substance Registry System]

7446-11-9(EPA Substance)
Safety DataBack Directory
[Hazard Codes ]

O,T+,C
[Risk Statements ]

R45:May cause cancer.
R8:Contact with combustible material may cause fire.
R14:Reacts violently with water.
R26:Very Toxic by inhalation.
R34:Causes burns.
[Safety Statements ]

S53:Avoid exposure-obtain special instruction before use .
S17:Keep away from combustible material .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S8:Keep container dry .
S25:Avoid contact with eyes .
[RIDADR ]

UN 1829 8/PG 1
[WGK Germany ]

1
[RTECS ]

WT4830000
[HazardClass ]

8
[PackingGroup ]

I
[Safety Profile]

Poison by inhalation. Human systemic effects by inhalation: cough and other pulmonary and olfactory changes. A corrosive irritant to skin, eyes, and mucous membranes. Violent reaction with O2F2, PbO, NClO2, HClO4, P, tetrafluorethylene, acetonitrile, sulfuric acid, dimethyl sulfoxide, dioxan, water, diphenylmercury, formamide, iodine, pyridine, metal oxides. Reacts with steam to form corrosive, toxic fumes of sulfuric acid. When heated to decomposition it emits toxic fumes of SO,. See also SULFURIC ACID.
[Hazardous Substances Data]

7446-11-9(Hazardous Substances Data)
Raw materials And Preparation ProductsBack Directory
[Raw materials]

Sulfuric acid-->Sulfur-->Oxygen-->Sulfur dioxide-->Sulphur-->PYRITE
[Preparation Products]

Sulfuric acid-->Thionyl chloride-->Dimethyl sulfate-->Phenol-->Chlorosulfonic acid-->Copper(I) chloride-->Resorcinol-->Metanilic acid-->Sulfamic acid-->Sodium dodecyl sulfate-->Sodium dodecylbenzenesulphonate-->Chromium(III) oxide-->CALCIUM DODECYLBENZENE SULFONATE-->5-[2-(METHYLTHIO)PYRIMIDIN-4-YL]THIOPHENE-2-SULFONYL CHLORIDE-->Sodium N-cyclohexylsulfamate-->4-Phenylphenol-->3-OXO-3-THIOPHEN-2-YL-PROPIONIC ACID ETHYL ESTER-->4-Morpholineethanesulfonic acid-->monoethanolamine dodecyl sulfate-->4-(2-Methoxyethyl)Phenol-->sec-alkyl sodium sulfate-->alkyl phenylsufonate-->stearyltoluene sodium sulfonate
Hazard InformationBack Directory
[General Description]

SULFUR TRIOXIDE(7446-11-9), is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. SULFUR TRIOXIDE(7446-11-9) reacts violently with water to form sulfuric acid with the release of heat. SULFUR TRIOXIDE(7446-11-9) is corrosive to metals and tissue. SULFUR TRIOXIDE(7446-11-9) causes eye and skin burns. Ingestion causes severe burns of mouth esophagus and stomach. The vapor is very toxic by inhalation. SULFUR TRIOXIDE(7446-11-9) is a fire risk when in contact with organic materials such as wood, cotton, fiberboard, etc.
[Reactivity Profile]

The reaction of SULFUR TRIOXIDE and oxygen difluoride is very vigorous and explosions occur if the reaction is carried out in the absence of a solvent [J. Chem. Eng. Data 13(4):529-531. 1968]. The reaction of sulfur trioxide in excess with tetrafluoroethylene causes explosive decomposition to carbonyl fluoride and sulfur dioxide [Chem. Eng. News 49(22):3. 1971]. The reaction of anhydrous perchloric acid with sulfur trioxide is violent and accompanied by the evolution of considerable heat (Pascal 16:300 1931-34). Liquid sulfur trioxide reacts violently with nitryl chloride, even at 75° C. The reaction of sulfur trioxide and lead oxide causes white luminescence [Mellor 7:654 1946-47]. The combination of iodine, pyridine, sulfur trioxide, and formamide developed a gas over pressurization after several months. This is due to the slow formation of sulfuric acid, from external water or dehydration of the formamide to hydrogen cyanide.
[Air & Water Reactions]

Combines with water with explosive force, forming sulfuric acid due to its acidity Sulfur trioxide chars most organic substances. On exposure to air SULFUR TRIOXIDE absorbs moisture rapidly, emitting dense white fumes [Merck 11th ed. 1989].
[Health Hazard]

This material is highly toxic. It is an irritant and corrosive to mucous membranes. Poisonous if inhaled or swallowed. Contact causes severe burns to skin and eyes.
[Potential Exposure]

Sulfur trioxide is used as a sulfating and sulfonating agent for detergent, lubricating oil additives, and other organic compounds; in solar energy collectors. It is also used as an intermediate in sulfuric acid manufacture and in making explosives.
[Fire Hazard]

Fire risk in contact with organic materials. An explosive increase in vapor pressure occurs when the alpha form melts. Combines with water with explosive violence, forming sulfuric acid. May ignite other combustible materials (wood, paper, oil, etc.). Flammable poisonous gases may accumulate in tanks and hopper cars. Runoff to sewer may create fire or explosion hazard. Forms sulfuric acid on contact with water. Avoid water and organic materials. On exposure to air, SULFUR TRIOXIDE absorbs moisture and emits dense white fumes.
[First aid]

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 30 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. If victim is conscious, administer water, or milk. Do not induce vomiting. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy.
[Shipping]

UN1829 Sulfur trioxide, stabilized, Hazard class: 8; Labels: 8-Corrosive material, 6.1-Poisonous Inhalation Hazard, Inhalation Hazard Zone B.
[Incompatibilities]

Combustible and Corrosive. A strong oxidizer. Reacts violently with water, steam or moisture, releasing corrosive hydrosulfuric acid. Violent reactions occur on contact with strong bases; strong acids, chemically active metals; reducing agents; finely divided metal; cyanides, nitrates, picrates, fulminates, chlorates, sulfides, carbides, phosphorus, dioxygen difluoride, barium oxide; lead oxide; diphenyl mercury; alcohols, nitryl chloride; acetonitrile, dioxane, tetrafluoroethylene.
[Chemical Properties]

Sulfur trioxide, S03, also known as sulfuric anhydride, needles or polymer, exists in a number of modifications that differ in molecular species and crystalline form. It has a white,ice-like modification that melts at 16°C (61°F) and two other as bestos-like forms that melt at the higher temperatures of 33 and 62°C (90 and 144 °F). The colorless liquid or gas form has irritating, toxic fumes and boils at 45 °C (112 °F).
Sulfur trioxide
Sulfur trioxide is a highly reactive substance, a strong oxidizing agent,and a fire hazard. It reacts with metallic oxides to form sulfates and with water to form sulfuric acid. Sulfur trioxide is used for sulfonation.
[Waste Disposal]

Return refillable compressed gas cylinders to supplier. Nonrefillable cylinders should be disposed of in accordance with local, state and federal regulations. Allow remaining gas to vent slowly into atmosphere in an unconfined area or exhaust hood. Refillabletype cylinders should be returned to original supplier with any valve caps and outlet plugs secured and valve protection caps in place.
[Physical properties]

Colorless liquid at ambient temperature and atmospheric pressure; fumes in air.
Sulfur trioxide tends to polymerize, particularly in the presence of traces of water or sulfuric acid. The rate of its polymerization, however, decreasesgreatly as its freezing point is approached. Solid (polymeric) sulfur trioxide exists in three polymorphic phases: alpha-, beta- and gamma- modifications.
The alpha phase is made up of ice-like needles having polymeric crosslinked structure. It melts at 62.3°C and has a vapor pressure of 73 torr at 25°C.
The beta phase is a metastable allotrope with white, asbestos-like, lustrous needles consisting of polymeric molecules, melting at 32.5°C, and with vapor pressure 344 torr at 25°C.
The gamma modification at ordinary temperatures can exist in solid or liquid form. In solid form it is a colloidal ice-like mass melting at 16.8°C. In the liquid form it has a density of 1.9224 g/mL, boiling at 44.8°C. It has a vapor pressure of 433 torr at 25°C. The gamma phase consists of both cyclic trimer and monomer molecules. When solid sulfur trioxide melts, it converts to its gamma phase which on solidification changes to alpha modification.
Critical temperature of SO3 is 217.8°C; critical pressure 80.97 atm; critical density 0.63 g/cm3; the dielectric constant of liquid SO3 at 18°C is 3.11.
Sulfur trioxide dissolves in water forming sulfuric acid and generating large heat.
[Definition]

ChEBI: Sulfur trioxide is a sulfur oxide.
[Production Methods]

Sulfur trioxide is produced as an intermediate in manufacturing sulfuric acid by the contact process (See Sulfuric Acid). The process involves catalytic oxidation of sulfur dioxide to trioxide.
Sulfur trioxide is prepared in the laboratory by heating fuming sulfuric acid, condensing its vapors, and collecting in a cool receiver. When vapors are condensed below 27°C in the presence of trace moisture, all three polymorphic phases of SO3 are produced. They can be separated by fractional distillation. Condensation of the vapors above 27°C forms the liquid variety of gamma-sulfur trioxide.
[Hazard]

Oxidizing agent, fire risk in contact with organic materials, an explosive increase in vapor pressure occurs when the α form melts. The anhydride combines with water, forming sulfuric acid and evolving heat. Highly toxic, strong irritant to tissue.
[Flammability and Explosibility]

Nonflammable
[storage]

The vapour pressure of Sulfur trioxide rises rapidly with increasing temperatures and, when the α-form melts, the pressure rise is explosive; consequently transport and storage containers must withstand pressures of 10 to 15 atm. Sulfur trioxide reacts vigorously and highly exothermically with water to produce hydrosulphuric acid. When exposed to moist air, it fumes and forms a mist of sulphuric acid which eventually fills all the available space; it also corrodes metals. It is a powerful oxidizing agent and, in the liquid phase, carbonizes organic materials.
Material Safety Data Sheet(MSDS)Back Directory
[msds information]

Sulfuric anhydride(7446-11-9).msds
Well-known Reagent Company Product InformationBack Directory
[Acros Organics]

Sulfur trioxide, packaged in ampules, stabilized, 99%(7446-11-9)
[Sigma Aldrich]

7446-11-9(sigmaaldrich)
7446-11-9 suppliers list
Company Name: Henan Tianfu Chemical Co.,Ltd.
Tel: +86-0371-55170693 +86-19937530512 , +86-19937530512
Website: https://www.tianfuchem.com/
Company Name: Hubei Jusheng Technology Co.,Ltd.
Tel: 18871490254
Website: www.hubeijusheng.com
Company Name: Hubei xin bonus chemical co. LTD
Tel: 86-13657291602
Website: www.chemicalbook.com/ShowSupplierProductsList1549548/0.htm
Company Name: CONIER CHEM AND PHARMA LIMITED
Tel: +8618523575427 , +8618523575427
Website: http://www.conier.com/
Company Name: Richest Group Ltd
Tel: 18017061086
Website: www.chemicalbook.com/ShowSupplierProductsList664261/0.htm
Company Name: Hefei TNJ Chemical Industry Co.,Ltd.
Tel: 0551-65418671
Website: https://www.tnjchem.com
Company Name: Shaanxi Dideu Medichem Co. Ltd
Tel: +86-029-89586680 +86-18192503167 , +86-18192503167
Website: www.dideu.com
Company Name: Baoji Guokang Healthchem co.,ltd
Tel: +8615604608665 15604608665 , 15604608665
Website: www.gk-bio.com
Company Name: Industrial Solvents And Chemicals Pvt Ltd  
Tel: +91-2222841180 +91-9819294980
Website: www.iscpl.com
Company Name: Khaitan Chemicals And Fertilizers Ltd  
Tel: +91-7314753666 +91-7314753666
Website: www.kcfl.co.in
Company Name: Guljag Industries Limited  
Tel: +91-9772500432 +91-9649049000
Website: www.guljag.com
Company Name: Bodal Chemicals Ltd  
Tel: +91-9909950857 +91-9825034567
Website: www.bodal.com
Company Name: Shree Sulphurics Pvt Ltd (SSPL)  
Tel: +91-2224915709 +91-9833300322
Website: www.shreesulphuric.com
Company Name: Aarti Industries Limited (AIL)  
Tel: +91-84596144931 +91-9920899935
Website: www.aarti-industries.com
Company Name: Mainchem Co., Ltd.  
Tel: +86-0592-6210733
Website: https://www.mainchem.com
Company Name: Chemwill Asia Co.,Ltd.  
Tel: 86-21-51086038
Website: www.chemwill.com
Company Name: Shanghai Hanhong Scientific Co.,Ltd.  
Tel: 021-54306202 13764082696;
Website: https://www.hanhongsci.com
Company Name: Spectrum Chemical Manufacturing Corp.  
Tel: 021-021-021-67601398-809-809-809 15221380277
Website: www.spectrumchemical.com/oa_html/index.jsp?minisite=10020&respid=22372&language=us
Tags:7446-11-9 Related Product Information
24424-99-5 13813-19-9 1309-64-4 108-55-4 1333-82-0 108-30-5 552-30-7 85-44-9 108-31-6 1314-56-3 96607-26-0 1327-53-3 7704-34-9 8014-95-7 7664-93-9 26412-87-3 108-24-7 7446-11-9