ChemicalBook > CAS DataBase List > Sulfur trioxide

Sulfur trioxide

Product Name
Sulfur trioxide
CAS No.
7446-11-9
Chemical Name
Sulfur trioxide
Synonyms
SO3;SULFURIC ANHYDRIDE;SULPHUR TRIOXIDE;Schwefeltrioxid;Sulfan;SULFAN(R);sulfuricoxide;Sulfuric oxide;SULFUR TRIOXIDE;Sulfur oxide (SO3)
CBNumber
CB5854196
Molecular Formula
O3S
Formula Weight
80.06
MOL File
7446-11-9.mol
More
Less

Sulfur trioxide Property

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
Water Solubility 
reacts violently
Merck 
13,9069
Dielectric constant
3.1(18℃)
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.
CAS DataBase Reference
7446-11-9(CAS DataBase Reference)
NIST Chemistry Reference
Sulfur trioxide(7446-11-9)
EPA Substance Registry System
Sulfur trioxide (7446-11-9)
More
Less

Safety

Hazard Codes 
O,T+,C
Risk Statements 
45-8-14-26-34-37-35
Safety Statements 
53-17-26-36/37/39-45-8-25-30
RIDADR 
UN 1829 8/PG 1
WGK Germany 
1
RTECS 
WT4830000
HazardClass 
8
PackingGroup 
I
Hazardous Substances Data
7446-11-9(Hazardous Substances Data)
More
Less

Hazard and Precautionary Statements (GHS)

Symbol(GHS)
Signal word
Danger
Hazard statements

H314Causes severe skin burns and eye damage

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P310Immediately call a POISON CENTER or doctor/physician.

More
Less

N-Bromosuccinimide Price

American Custom Chemicals Corporation
Product number
GAS0000037
Product name
SULFUR TRIOXIDE
Purity
95.00%
Packaging
1G
Price
$662.16
Updated
2021/12/16
American Custom Chemicals Corporation
Product number
GAS0000037
Product name
SULFUR TRIOXIDE
Purity
95.00%
Packaging
5G
Price
$1087.84
Updated
2021/12/16
American Custom Chemicals Corporation
Product number
GAS0000037
Product name
SULFUR TRIOXIDE
Purity
95.00%
Packaging
2.5KG
Price
$2870
Updated
2021/12/16
More
Less

Sulfur trioxide Chemical Properties,Usage,Production

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 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.

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.

Uses

Sulfur trioxide may be used in the synthesis of methane sulfonic acid (MSA) by sulfonating methane. it may also be used in the synthesis of fluorinated β-sultones by reacting with fluoroolefins.

Uses

Sulfur trioxide is used as an intermediate in the manufacture of sulphuric acid and oleum for sulphonation, in particular, of dyes and dye-stuffs, and for the production of anhydrous nitric acid and explosives. Solid Sulfur trioxide is marketed under such names as Sulphan and Triosul, and is used primarily for sulphonation of organic acids. Sulphur tetrafluoride is a fluorinating agent. Sulphur hexafluoride serves as a gaseous insulator in high-voltage electric installations. Sulphyryl fluoride is used as an insecticide and a fumigant.
Sulfonation of organic compounds, especially nonionic detergents, solar energy collectors. It is usually generated in the plant where it is to be used.

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.

General Description

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

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].

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.

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.

Health Hazard

Sulfur trioxide 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.

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.

Flammability and Explosibility

Non flammable

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.

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.

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.

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.

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.

More
Less

Sulfur trioxide Suppliers

Shanghai Hanhong Scientific Co.,Ltd.
Tel
021-54306202 13764082696
Email
info@hanhongsci.com
Country
China
ProdList
42958
Advantage
64
Spectrum Chemical Manufacturing Corp.
Tel
021-021-021-67601398-809-809-809 15221380277
Fax
021-57711696
Email
marketing_china@spectrumchemical.com
Country
China
ProdList
9658
Advantage
60
Chizhou Kailong Import and Export Trade Co., Ltd.
Tel
Fax
-
Email
xg01_gj@163.com
Country
China
ProdList
9484
Advantage
50
Sigma-Aldrich
Tel
021-61415566 800-8193336
Email
orderCN@merckgroup.com
Country
China
ProdList
51456
Advantage
80
Shandong Xiya Chemical Co., Ltd.
Tel
4009903999 13395398332
Fax
0539-6365991
Email
sales@xiyashiji.com
Country
China
ProdList
20806
Advantage
60
Shanghai Orgchem Co.,Ltd.
Tel
+86-21-5877 1921
Fax
+86-21-5877 1925
Email
info@chemofchina.com
Country
China
ProdList
9653
Advantage
55
Hefei TNJ Chemical Industry Co.,Ltd.
Tel
+86-0551-65418671 +8618949823763
Fax
0551-65418697
Email
sales@tnjchem.com
Country
China
ProdList
34563
Advantage
58
Baoji Guokang Healthchem co.,ltd
Tel
+8615604608665 15604608665
Email
dominicguo@gk-bio.com
Country
CHINA
ProdList
9414
Advantage
58
Shaanxi Dideu Medichem Co. Ltd
Tel
+86-029-89586680 +86-18192503167
Fax
+86-29-88380327
Email
1026@dideu.com
Country
China
ProdList
7724
Advantage
58
Chemwill Asia Co.,Ltd.
Tel
86-21-51086038
Fax
86-21-51861608
Email
chemwill_asia@126.com
Country
CHINA
ProdList
23912
Advantage
58
Hubei Jusheng Technology Co.,Ltd.
Tel
18871490254
Fax
027-59599243
Email
linda@hubeijusheng.com
Country
CHINA
ProdList
28172
Advantage
58
Hubei xin bonus chemical co. LTD
Tel
86-13657291602
Fax
027-59338440
Email
linda@hubeijusheng.com
Country
CHINA
ProdList
22963
Advantage
58
CONIER CHEM AND PHARMA LIMITED
Tel
+8618523575427
Email
sales@conier.com
Country
China
ProdList
49374
Advantage
58
Richest Group Ltd
Tel
18017061086
Email
oled@richest-group.com
Country
CHINA
ProdList
5600
Advantage
58
WUHAN JIXINYIBANG BIOTECHNOLOGY .,LTD
Tel
027-59768661 13297943853
Email
1704244976@qq.com
Country
China
ProdList
4673
Advantage
58
Jiangsu Runfeng Synthetic Technology Co., Ltd.
Tel
18551497631 18551497631
Email
507167383@qq.com
Country
China
ProdList
5001
Advantage
58
Jiangsu Pules Bio-tech Co.,Ltd
Tel
0513-66017706 18551496367
Email
2186883463@qq.com
Country
China
ProdList
5000
Advantage
58
Pand (Shanghai) international trade Co., LTD
Tel
18662931292 18662931292
Email
3404730042@qq.com
Country
China
ProdList
4800
Advantage
58
Nantong Zhonghe Chemical New Materials Co., Ltd
Tel
13003551299 13003551299
Email
2369399482@qq.com
Country
China
ProdList
7566
Advantage
58
Jiangsu Raien Environmental Protection Technology Co., Ltd
Tel
0513-0513-66814573 16651336298
Email
16651336298@163.com
Country
China
ProdList
4167
Advantage
58
Shaanxi Xihua Chemical Industry Co., Ltd
Tel
17691182729 13992773979
Email
1049@dideu.com
Country
China
ProdList
7875
Advantage
58
Shandong Hongyuan Chemical Technology Co., LTD
Tel
13561560789
Email
xinxiaoxiao2008@126.com
Country
China
ProdList
345
Advantage
58
Shanghai Jasper Gas Co., Ltd.
Tel
021-13218776790 13218776790
Email
13218776790@163.com
Country
China
ProdList
443
Advantage
58
CHEMBSF (Shanghai) Biomedical Technology Co., Ltd
Tel
18117346937 18117346937
Email
18117346937@163.com
Country
China
ProdList
4976
Advantage
58
Tel
13051508530
Email
114458501name@qq.com
Country
CHINA
ProdList
3186
Advantage
58
Henan Tianfu Chemical Co.,Ltd.
Tel
+86-0371-55170693 +86-19937530512
Fax
0371-55170693
Email
info@tianfuchem.com
Country
China
ProdList
21634
Advantage
55
SUZHOU SENFEIDA CHEMICAL CO.,LTD
Tel
+86-0512-83500002 +8615195660023
Email
sales@senfeida.com
Country
China
ProdList
23046
Advantage
58
Changzhou Houmei Chemical Works
Tel
--
Fax
--
Email
jvd@pyridinechem.com
Country
China
ProdList
392
Advantage
47
Nantong Jinrui Chemical Co., Ltd
Tel
--
Fax
--
Email
admin@jinruichemical.com
Country
China
ProdList
12
Advantage
50
Tianjin Bohai Chemical Industry Group Supply And Sales Co., Ltd
Tel
--
Fax
--
Email
info@tjbhgx.com
Country
China
ProdList
46
Advantage
50
Shanghai Huayi Group Shanghai Shangliu Chemical Co., LTD.
Tel
--
Fax
--
Email
info@cssaw.com
Country
China
ProdList
12
Advantage
54
Jiangsu Nantong Da Lun Chemical Industry Co.,Ltd.
Tel
--
Fax
--
Country
China
ProdList
13
Advantage
58
China Petrochemical Group of Shengli Petroleum Administration-largest chemical plant
Tel
--
Fax
--
Email
office@shengdachem.com
Country
China
ProdList
16
Advantage
60
Shanghai Yuanji Chemical Co., Ltd
Tel
--
Fax
--
Email
shyjhg@gmail.com
Country
China
ProdList
474
Advantage
64
Chemding Trading Co., Ltd
Tel
--
Fax
--
Country
China
ProdList
45
Advantage
34
Yancheng Huilong Chemical Co., Ltd
Tel
--
Fax
--
Email
zbl@huilongchem.com
Country
China
ProdList
14
Advantage
38
Jiangxi Xunpeng Chemical Co., Ltd.
Tel
--
Fax
--
Email
sales@xunpengchem.com
Country
China
ProdList
50
Advantage
42

7446-11-9, Sulfur trioxideRelated Search:


  • SULFURIC ANHYDRIDE
  • SULFUR TRIOXIDE
  • SULPHUR TRIOXIDE
  • Oxosulfane dioxide
  • SULFUR TRIOXIDE, 99%, PACKAGED IN AMPULES, STABILIZED
  • Sulfur(VI) trioxide
  • Sulfan
  • Sulfur oxide (SO3)
  • Sulfur trioxide, stabilized
  • Sulfuric oxide
  • Sulfuricacidanhydride
  • sulfuricoxide
  • sulfurtrioxide,stabilized
  • SULFAN(R)
  • Liquid Sulfur Trioxide
  • Sulfur trioxide, packaged in ampules, stabilized, 99%
  • Schwefeltrioxid
  • Sulfur trioxide,liquid
  • sulfur trioxide,inhibited
  • SO3
  • Sulfur trioxide ISO 9001:2015 REACH
  • 7446-11-9
  • Synthetic Reagents
  • Sulfur-Based
  • Oxidation
  • Compressed and Liquefied Gases
  • Mineral Acid Anhydride
  • Inorganics