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
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Henry's Law data
  • Ion clustering data
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
  • Switch to SI units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes

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 (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), References, Notes

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

Mass spectrum (electron ionization)

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

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

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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]

Notes

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  AE	Appearance energy
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  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

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.