Water
- Formula: H2O
- Molecular weight: 18.0153
- IUPAC Standard InChI: InChI=1S/H2O/h1H2
- 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:
- Phase change 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
- Mass spectrum (electron ionization)
- Gas Chromatography
- Fluid Properties
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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.
| 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 |
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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°liquid | -285.830 ± 0.040 | kJ/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
| ΔfH°liquid | -285.83 | kJ/mol | Review | Chase, 1998 | Data last reviewed in March, 1979 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid | 69.95 ± 0.03 | J/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid,1 bar | 69.95 | J/mol*K | Review | Chase, 1998 | Data last reviewed in March, 1979 |
Liquid 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) | 298. to 500. |
|---|---|
| A | -203.6060 |
| B | 1523.290 |
| C | -3196.413 |
| D | 2474.455 |
| E | 3.855326 |
| F | -256.5478 |
| G | -488.7163 |
| H | -285.8304 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in March, 1979 |
IR Spectrum
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Vibrational and/or electronic energy levels, References, Notes
Data compiled by: Coblentz Society, Inc.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Vibrational and/or electronic energy levels
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, IR Spectrum, 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: C2ν Symmetry Number σ = 2
| Sym. | No | Approximate | Selected Freq. | Infrared | Raman | Comments | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Species | type of mode | Value | Rating | Value | Phase | Value | Phase | |||
| a1 | 1 | Sym str | 3657 | A | 3656.65 | gas | 3654 | gas | ||
| a1 | 2 | Bend | 1595 | A | 1594.59 | gas | ||||
| b1 | 3 | Anti str | 3756 | A | 3755.79 | gas | ||||
Source: Shimanouchi, 1972
Notes
| A | 0~1 cm-1 uncertainty |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, IR Spectrum, 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]
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, IR Spectrum, Vibrational and/or electronic energy levels, References
- Symbols used in this document:
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) ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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