sulphur trioxide

• Formula: O₃S
• Molecular weight: 80.063
• IUPAC Standard InChI: InChI=1S/O3S/c1-4(2)3 Copy

  
• IUPAC Standard InChIKey: AKEJUJNQAAGONA-UHFFFAOYSA-N Copy
• CAS Registry Number: 7446-11-9
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
• Other names: Sulfur trioxide
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• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Henry's Law data
  • Ion clustering data
  • Vibrational and/or electronic energy levels
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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View table.

Phase change data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Enthalpy of vaporization

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Enthalpy of fusion

Gas phase ion energetics data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

View reactions leading to O₃S⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Kondrat'ev and Strizhov, 1985
Kondrat'ev, S.N.; Strizhov, B.V., Zh. Fiz. Khim., 1985, 59, 2933. [all data]

Abercromby and Tiley, 1963
Abercromby, D.C.; Tiley, P.F., 937. The Condensed phases of sulphur trioxide. Part II. Vapour pressure of the liquid at temperatures up to the critical point, J. Chem. Soc., 1963, 4902, https://doi.org/10.1039/jr9630004902 . [all data]

Abercromby and Tiley, 1963, 2
Abercromby, D.C.; Tiley, P.F., The Condensed Phases of Sulphur Trioxide. Part II. Vapour Pressure of the Liquid at Temperatures up to the Critical Point, J. Chem. Soc., 1963, 4902-4904, https://doi.org/10.1039/jr9630004902 . [all data]

Kondrat'ev and Strizhov, 1989
Kondrat'ev, S.N.; Strizhov, B.V., Russ. J. Phys. Chem., 1989, 63, 656. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Gleason, 1987
Gleason, J.F., as cited in 95MIL/VIG, Ph.D. dissertation, Univ. of Colorado,, 1987. [all data]

Dobrin, Boo, et al., 2000
Dobrin, S.; Boo, B.H.; Alconcel, L.S.; Continetti, R.E., Photoelectron spectroscopy of SO3- at 355 and 266 nm, J. Phys. Chem. A, 2000, 104, 46, 10695-10700, https://doi.org/10.1021/jp0025680 . [all data]

Rudny, Sidorov, et al., 1985
Rudny, E.B.; Sidorov, L.N.; Voyk, O.M., Heterolytic Dissociation of Potassium Sulfate in the Gas Phase and Heats of Formation for Trioxosulfate(1^-), Tetraoxosulfate(1^-), and Potassium Sulfate(KSO₄^-) Ions, High Temp., 1985, 23, 238. [all data]

Rothe, Tang, et al., 1975
Rothe, E.W.; Tang, S.Y.; Reck, G.P., Measurement of electron affinities of O₃, SO₂, and SO₃ by collisional ionization, J. Chem. Phys., 1975, 62, 3829. [all data]

Snow and Thomas, 1990
Snow, K.B.; Thomas, T.F., Mass spectrum, ionization potential, and appearance potentials for fragment ions of sulfuric acid vapor, Int. J. Mass Spectrom. Ion Processes, 1990, 96, 49. [all data]

Smith and Stevenson, 1981
Smith, O.I.; Stevenson, J.S., Determination of cross sections for formation of parent and fragment ions by electron impact from SO₂ and SO₃, J. Chem. Phys., 1981, 74, 6777. [all data]

Lloyd, Roberts, et al., 1976
Lloyd, D.R.; Roberts, P.J.; Hillier, I.H.; Shenton, I.C., On the photoelectron spectrum of sulphur trioxide, Mol. Phys., 1976, 31, 1549. [all data]

Alderdice and Dixon, 1976
Alderdice, D.S.; Dixon, R.N., Photoelectron spectrum of sulphur trioxide, J. Chem. Soc. Faraday Trans. 2, 1976, 72, 372. [all data]

Mines and Thomas, 1974
Mines, G.W.; Thomas, R.K., The photoelectron spectrum of sulphur trioxide: Jahn-Teller distortion in SO₃⁺, Proc. R. Soc. London A:, 1974, 336, 355. [all data]

DeKock and Lloyd, 1973
DeKock, R.L.; Lloyd, D.R., The He^Iphotoelectron spectrum of sulphur trioxide, J. Chem. Soc. Dalton Trans., 1973, 526. [all data]

Ficalora, Uy, et al., 1968
Ficalora, P.J.; Uy, O.M.; Muenow, D.W.; Margrave, J.L., Mass spectrometric studies at high temperatures: XXIX. Thermal decomposition and sublimation of alkali metal sulfates, J. Am. Ceram. Soc., 1968, 51, 574. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  Tfus	Fusion (melting) point
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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