Water
- Formula: H2O
- Molecular weight: 18.0153
- IUPAC Standard InChIKey: XLYOFNOQVPJJNP-UHFFFAOYSA-N
- 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:
- Other names: Water vapor; Distilled water; Ice; H2O; Dihydrogen oxide; steam; Tritiotope
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- Information on this page:
- Other data available:
- Condensed phase thermochemistry data
- 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
- Vibrational and/or electronic energy levels
- Gas Chromatography
- Fluid Properties
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Gas phase thermochemistry data
Go To: Top, Phase change 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.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -241.826 ± 0.040 | kJ/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
ΔfH°gas | -241.83 | kJ/mol | Review | Chase, 1998 | Data last reviewed in March, 1979 |
Quantity | Value | Units | Method | Reference | Comment |
S°gas,1 bar | 188.835 ± 0.010 | J/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
S°gas,1 bar | 188.84 | J/mol*K | Review | Chase, 1998 | Data last reviewed in March, 1979 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 500. to 1700. | 1700. to 6000. |
---|---|---|
A | 30.09200 | 41.96426 |
B | 6.832514 | 8.622053 |
C | 6.793435 | -1.499780 |
D | -2.534480 | 0.098119 |
E | 0.082139 | -11.15764 |
F | -250.8810 | -272.1797 |
G | 223.3967 | 219.7809 |
H | -241.8264 | -241.8264 |
Reference | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in March, 1979 | Data last reviewed in March, 1979 |
Phase change 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 compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 373.17 ± 0.04 | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ptriple | 0.0061 | bar | N/A | Sato, Watanabe, et al., 1991 | Uncertainty assigned by TRC = 1.×10-7 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 647. ± 2. | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 220.64 | bar | N/A | Sato, Watanabe, et al., 1991 | Uncertainty assigned by TRC = 0.05 bar; TRC |
Pc | 220.60 | bar | N/A | Brunner, 1990 | Uncertainty assigned by TRC = 0.12 bar; TRC |
Pc | 220.46 | bar | N/A | Morita, Sato, et al., 1989 | Uncertainty assigned by TRC = 0.25 bar; based on analysis of their obs. PVT and vapor pressure data some other data from literature; TRC |
Pc | 220.64 | bar | N/A | Aleksandrov, 1986 | Uncertainty assigned by TRC = 0.30 bar; TRC |
Pc | 220.64 | bar | N/A | Sifner, 1985 | Uncertainty assigned by TRC = 0.0001 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 17.9 | mol/l | N/A | Sato, Watanabe, et al., 1991 | Uncertainty assigned by TRC = 0.2 mol/l; TRC |
ρc | 17.91 | mol/l | N/A | Morita, Sato, et al., 1989 | Uncertainty assigned by TRC = 0.083 mol/l; based on analysis of obs. PVT and vapor pressure data; TRC |
ρc | 17.9 | mol/l | N/A | Aleksandrov, 1986 | Uncertainty assigned by TRC = 0.2 mol/l; TRC |
ρc | 17.9 | mol/l | N/A | Sifner, 1985 | Uncertainty assigned by TRC = 0.2 mol/l; TRC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
379. to 573. | 3.55959 | 643.748 | -198.043 | Liu and Lindsay, 1970 | Coefficents calculated by NIST from author's data. |
273. to 303. | 5.40221 | 1838.675 | -31.737 | Bridgeman and Aldrich, 1964 | Coefficents calculated by NIST from author's data. |
304. to 333. | 5.20389 | 1733.926 | -39.485 | Bridgeman and Aldrich, 1964 | Coefficents calculated by NIST from author's data. |
334. to 363. | 5.0768 | 1659.793 | -45.854 | Bridgeman and Aldrich, 1964 | Coefficents calculated by NIST from author's data. |
344. to 373. | 5.08354 | 1663.125 | -45.622 | Bridgeman and Aldrich, 1964 | Coefficents calculated by NIST from author's data. |
293. to 343. | 6.20963 | 2354.731 | 7.559 | Gubkov, Fermor, et al., 1964 | Coefficents calculated by NIST from author's data. |
255.9 to 373. | 4.6543 | 1435.264 | -64.848 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Mass spectrum (electron ionization)
Go To: Top, Gas 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: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
NIST MS number | 7 |
References
Go To: Top, Gas phase thermochemistry data, Phase change 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.
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]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), 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) Tboil Boiling point Tc Critical temperature ΔfH°gas Enthalpy of formation of gas at standard conditions ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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