Sulfur trioxide

Sulfur trioxide


Names
Preferred IUPAC name
Sulfur trioxide
Systematic IUPAC name
Sulfonylideneoxidane
Other names
Sulfuric anhydride, Sulfur(VI) oxide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.028.361 Edit this at Wikidata
EC Number
  • 231-197-3
1448
RTECS number
  • WT4830000
UNII
UN number UN 1829
  • InChI=1S/O3S/c1-4(2)3 checkY
    Key: AKEJUJNQAAGONA-UHFFFAOYSA-N checkY
  • InChI=1/O3S/c1-4(2)3
    Key: AKEJUJNQAAGONA-UHFFFAOYAX
  • (monohydrate): InChI=1S/O3S.H2O/c1-4(2)3;/h;1H2
    Key: DEUOBQUHDSDIFY-UHFFFAOYSA-N
  • monomer: O=S(=O)=O
  • γ-trimer: O=S0(=O)OS(=O)(=O)OS(=O)(=O)O0
  • α/β polymer: OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)OS(=O)(=O)O
  • (monohydrate): O.O=S(=O)=O
Properties
SO3
Molar mass 80.066 g/mol
Appearance Colorless to white crystalline solid which will fume in air.[2] Colorless liquid and gas.[3]
Odor Varies. Vapor is pungent; like sulfur dioxide.[4] Mist is odorless.[3]
Density 1.92 g/cm3, liquid
Melting point 16.9 °C (62.4 °F; 290.0 K)
Boiling point 45 °C (113 °F; 318 K)
Reacts to give sulfuric acid
Thermochemistry
256.77 JK−1mol−1
−395.7 kJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Highly corrosive, extremely strong dehydrating agent
GHS labelling:
GHS05: Corrosive GHS07: Exclamation mark
Danger
H314, H335
P261, P280, P305+P351+P338, P310[5]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazard W+OX: Reacts with water in an unusual or dangerous manner AND is oxidizer
3
0
3
W
OX
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
rat, 4 hr 375 mg/m3[citation needed]
Safety data sheet (SDS) ICSC 1202
Related compounds
Other cations
 Selenium trioxide
Tellurium trioxide
Polonium trioxide
Related sulfur oxides
 Sulfur monoxide
Sulfur dioxide
Related compounds
 Sulfuric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Sulfur trioxide (alternative spelling sulphur trioxide) is the chemical compound with the formula SO3. It has been described as "unquestionably the most [economically] important sulfur oxide".[1] It is prepared on an industrial scale as a precursor to sulfuric acid.

Sulfur trioxide exists in several forms: gaseous monomer, crystalline trimer, and solid polymer. Sulfur trioxide is a solid at just below room temperature with a relatively narrow liquid range. Gaseous SO3 is the primary precursor to acid rain.[6]

  1. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 703–704. ISBN 978-0-08-037941-8.
  2. ^ "SULFUR TRIOXIDE CAMEO Chemicals NOAA". Cameochemicals.noaa.gov.
  3. ^ a b Lerner, L. (2011). Small-Scale Synthesis of Laboratory Reagents with Reaction Modeling. CRC Press. p. 10. ISBN 9781439813133. LCCN 2010038460.
  4. ^ "Substance:Sulfur trioxide - Learn Chemistry Wiki". Rsc.org.
  5. ^ "Sulfur trioxide 227692" (PDF). SO3. Archived from the original on 2020-09-01. Retrieved 1 September 2020.
  6. ^ Thomas Loerting; Klaus R. Liedl (2000). "Toward elimination of descrepancies between theory and experiment: The rate constant of the atmospheric conversion of SO3 to H2SO4". Proceedings of the National Academy of Sciences of the United States of America. 97 (16): 8874–8878. Bibcode:2000PNAS...97.8874L. doi:10.1073/pnas.97.16.8874. PMC 16788. PMID 10922048.