Sulfuric Acid

• Formula: H₂O₄S
• Molecular weight: 98.078
• IUPAC Standard InChI: InChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4) Copy

  
• IUPAC Standard InChIKey: QAOWNCQODCNURD-UHFFFAOYSA-N Copy
• CAS Registry Number: 7664-93-9
• 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: H2SO4; Dipping acid; Hydrogen sulfate; Oil of vitriol; Sulphuric acid; Acide sulfurique; Acido solforico; BOV; Matting acid; Nordhausen acid; Schwefelsaeureloesungen; Vitriol brown oil; Vitriol, oil of; Zwavelzuuroplossingen; O2S(OH)2; Battery acid; Electrolyte acid; Spirit of alum; Spirit of vitriol; Dihydrogen sulfate; Mattling acid; UN 1830 (Salt/Mix); UN 1832 (Salt/Mix); UN 2796 (Salt/Mix)
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Henry's Law data
  • Mass spectrum (electron ionization)
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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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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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

Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LL - Sharon G. Lias and Joel F. Liebman

Gas basicity at 298K

Protonation entropy at 298K

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

HO₄S^- +  =

By formula: HO₄S^- + H⁺ = H₂O₄S

Ion clustering 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 by: Michael M. Meot-Ner (Mautner) and Sharon G. Lias

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

(HO₄S^- • ) +  = (HO₄S^- • 2)

By formula: (HO₄S^- • H₂O₄S) + H₂O₄S = (HO₄S^- • 2H₂O₄S)

Free energy of reaction

(HO₄S^- • 2) +  = (HO₄S^- • 3)

By formula: (HO₄S^- • 2H₂O₄S) + H₂O₄S = (HO₄S^- • 3H₂O₄S)

Free energy of reaction

(HO₄S^- • 3) +  = (HO₄S^- • 4)

By formula: (HO₄S^- • 3H₂O₄S) + H₂O₄S = (HO₄S^- • 4H₂O₄S)

Free energy of reaction

(HO₄S^- • 4) +  = (HO₄S^- • 5)

By formula: (HO₄S^- • 4H₂O₄S) + H₂O₄S = (HO₄S^- • 5H₂O₄S)

Free energy of reaction

References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Ion clustering 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]

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]

Do, Klein, et al., 1998
Do, K.; Klein, T.P.; Pommering, C.A.; Bachrach, S.M.; Sunderlin, L.S., The gas-phase basicity of sulfuric acid, J. Am. Chem. Soc., 1998, 120, 6093. [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]

Wang, Nicholas, et al., 2000
Wang, X.B.; Nicholas, J.B.; Wang, L.S., Photoelectron spectroscopy and theoretical calculations of SO4- and HSO4-: Confirmation of high electron affinities of SO4 and HSO4, J. Phys. Chem. A, 2000, 104, 3, 504-508, https://doi.org/10.1021/jp992726r . [all data]

Viggiano, Henchman, et al., 1992
Viggiano, A.A.; Henchman, M.J.; Dale, F.; Deakyne, C.A.; Paulson, J.F., Gas-Phase Reactions of Weak Bronsted Bases I-, PO3-, HSO4-, FSO3-, and CF3SO3- with Strong Bronsted Acids H2SO4, FSO3H, and CF3SO3H - A Quantitative Study, J. Am. Chem. Soc., 1992, 114, 11, 4299, https://doi.org/10.1021/ja00037a039 . [all data]

House Jr. and Kemper, 1987
House Jr.; Kemper, K.A., Proton Affinities of Sulfate and Bisulfate Ions, J. Thermal Anal., 1987, 32, 6, 1855, https://doi.org/10.1007/BF01913977 . [all data]

Vigiano, Perry, et al., 1980
Vigiano, A.A.; Perry, R.A.; Albritton, D.L.; Ferguson, E.E.; Fehsenfeld, F.C., The role of H₂SO₄ in stratospheric negative ion chemistry, J. Geophys. Res., 1980, 85, 4551. [all data]

Adams, Smith, et al., 1986
Adams, N.G.; Smith, D.; Viggiano, A.A.; Paulson, J.F.; Henchman, M.J., Dissociative attachment reactions of electron with strong acid molecules, J. Chem. Phys., 1986, 84, 6728. [all data]

Arnold and Qiu, 1984
Arnold, F.; Qiu, S., Upper Stratosphere Negative Ion Composition Measurements and Infrared Trace Gas Abundances, Planet. Space Sci., 1984, 32, 2, 169, https://doi.org/10.1016/0032-0633(84)90151-X . [all data]

Arnold, Viggiano, et al., 1982
Arnold, F.; Viggiano, A.A.; Schlager, H., Implications for Trace Gases and Aerosols of Large Negative Ions Clusters in the Stratosphere, Nature, 1982, 297, 5865, 371, https://doi.org/10.1038/297371a0 . [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Ion clustering data, References

• Symbols used in this document:
  

  AE	Appearance energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  T	Temperature
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions

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