Water

• Formula: H₂O
• Molecular weight: 18.0153
• IUPAC Standard InChI: InChI=1S/H2O/h1H2 Copy

  
• IUPAC Standard InChIKey: XLYOFNOQVPJJNP-UHFFFAOYSA-N Copy
• CAS Registry Number: 7732-18-5
• 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.
• Isotopologues:
  • Deuterium oxide
  • Water-t
  • Water-¹⁸O
  • Water-d
  • Water-t₂
  • Deuterium oxide
• Other names: Water vapor; Distilled water; Ice; H2O; Dihydrogen oxide; steam; Tritiotope
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 100, reactions 101 to 150, reactions 151 to 200, reactions 201 to 250, reactions 251 to 300, reactions 301 to 350, reactions 351 to 400, reactions 401 to 450, reactions 451 to 500, reactions 501 to 550, reactions 551 to 600, reactions 601 to 650, reactions 651 to 700, reactions 701 to 750, reactions 751 to 800, reactions 801 to 850, reactions 851 to 900, reactions 901 to 950, reactions 951 to 1000, reactions 1001 to 1050, reactions 1051 to 1100, reactions 1101 to 1150, reactions 1151 to 1200, reactions 1201 to 1250, reactions 1251 to 1300, reactions 1301 to 1350, reactions 1351 to 1360
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Gas Chromatography
  • Fluid Properties
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
  • Reference simulation: SPC/E Water
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Data at NIST subscription sites:

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

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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Vibrational and/or electronic energy levels, 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 (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Condensed 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.

Liquid 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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Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Vibrational and/or electronic energy levels, References, Notes

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

Antoine Equation Parameters

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

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Vibrational and/or electronic energy levels

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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: Takehiko Shimanouchi

Symmetry:   C_2ν     Symmetry Number σ = 2

Source: Shimanouchi, 1972

Notes

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Vibrational and/or electronic energy levels, Notes

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

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

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

Sato, Watanabe, et al., 1991
Sato, H.; Watanabe, K.; Levelt Sengers, J.M.H.; Gallagher, J.S.; Hill, P.G.; Straub, J.; Wagner, W., Sixteen Thousand Evaluated Experimental Thermodynamic Property Data for Water and Steam, J. Phys. Chem. Ref. Data, 1991, 20, 1023. [all data]

Brunner, 1990
Brunner, E., Fluid Mixtures at High Pressures. 9. Phase Separation and Critical Phenomena in 23 (n-Alkane + Water) Mixtures., J. Chem. Thermodyn., 1990, 22, 335. [all data]

Morita, Sato, et al., 1989
Morita, T.; Sato, H.; Uematsu, M.; Watanabe, K., PVT Properties and Vapor-Pressures of Ordinary Water Substance in the Critical Region, Physica A: (Amsterdam), 1989, 156, 436. [all data]

Aleksandrov, 1986
Aleksandrov, A.A., Critical Parameters of Ordinary and Heavy Water, Teploenergetika, 1986, No. 1, 74. [all data]

Sifner, 1985
Sifner, O., Recommended Values of Critical Parameters of Ordinary and Heavy Water, Chem. Listy, 1985, 79, 199. [all data]

Liu and Lindsay, 1970
Liu, C.-T.; Lindsay, W.T., Jr., Vapor Pressure of D₂O from 106 to 300 ºC, J. Chem. Eng. Data, 1970, 15, 4, 510-513, https://doi.org/10.1021/je60047a015 . [all data]

Bridgeman and Aldrich, 1964
Bridgeman, O.C.; Aldrich, E.W., Vapor Pressure Tables for Water, J. Heat Transfer, 1964, 86, 2, 279-286, https://doi.org/10.1115/1.3687121 . [all data]

Gubkov, Fermor, et al., 1964
Gubkov, A.N.; Fermor, N.A.; Smirnov, N.I., Vapor Pressure of Mono-Poly Systems, Zh. Prikl. Khim. (Leningrad), 1964, 37, 2204-2210. [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Vibrational and/or electronic energy levels, References

• Symbols used in this document:
  

  Pc	Critical pressure
  Ptriple	Triple point pressure
  S°gas,1 bar	Entropy of gas at standard conditions (1 bar)
  S°liquid	Entropy of liquid at standard conditions
  S°liquid,1 bar	Entropy of liquid at standard conditions (1 bar)
  Tboil	Boiling point
  Tc	Critical temperature
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ρc	Critical density

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