Water (data page)

Chemical data page for water

This page provides supplementary data to the article properties of water.

Further comprehensive authoritative data can be found at the NIST Chemistry WebBook page on thermophysical properties of fluids.^[1]

Structure and properties

Thermodynamic properties

Liquid physical properties

Temperature dependence of the surface tension of pure water

Temperature dependence of the density of ice and water

Water/steam equilibrium properties

Vapor pressure formula for steam in equilibrium with liquid water:^[14]

${\displaystyle \log _{10}P=A-{\frac {B}{T-C}},}$

where P is equilibrium vapor pressure in kPa, and T is temperature in kelvins.

For T = 273 K to 333 K: A = 7.2326; B = 1750.286; C = 38.1.

For T = 333 K to 423 K: A = 7.0917; B = 1668.21; C = 45.1.

Data in the table above is given for water–steam equilibria at various temperatures over the entire temperature range at which liquid water can exist. Pressure of the equilibrium is given in the second column in kPa. The third column is the heat content of each gram of the liquid phase relative to water at 0 °C. The fourth column is the heat of vaporization of each gram of liquid that changes to vapor. The fifth column is the work PΔV done by each gram of liquid that changes to vapor. The sixth column is the density of the vapor.

Melting point of ice at various pressures

Data obtained from CRC Handbook of Chemistry and Physics 44th ed., p. 2390.

Table of various forms of ice

^‡Ice XI triple point is theoretical and has never been obtained

Phase diagram

Log-lin pressure–temperature phase diagram of water. The Roman numerals indicate various ice phases.

Water with dissolved NaCl

Water–NaCl phase diagram

Note: ρ is density, n is refractive index at 589 nm,^{[clarification needed]} and η is viscosity, all at 20 °C; T_eq is the equilibrium temperature between two phases: ice/liquid solution for T_eq < 0–0.1 °C and NaCl/liquid solution for T_eq above 0.1 °C.

Self-ionization

${\displaystyle pK_{w}=-\log([\mathrm {H} ^{+}][\mathrm {OH} ^{-}])}$

Spectral data

Self-diffusion coefficients

Additional data translated from German "Wasser (Stoffdaten)" page

The data that follows was copied and translated from the German language Wikipedia version of this page (which has moved to here). It provides supplementary physical, thermodynamic, and vapor pressure data, some of which is redundant with data in the tables above, and some of which is additional.

Physical and thermodynamic tables

In the following tables, values are temperature-dependent and to a lesser degree pressure-dependent, and are arranged by state of aggregation (s = solid, lq = liquid, g = gas), which are clearly a function of temperature and pressure. All of the data were computed from data given in "Formulation of the Thermodynamic Properties of Ordinary Water Substance for Scientific and General Use" (IAPWS , 1984) (obsolete as of 1995).^[22] This applies to:

• T – temperature in degrees Celsius
• V – specific volume in cubic decimeters per kilogram (1 dm³ is equivalent to 1 liter)
• H – specific enthalpy in kilojoules per kilogram
• U – specific internal energy in kilojoules per kilogram
• S – specific entropy in kilojoules per kilogram-kelvin
• c_p – specific heat capacity at constant pressure in kilojoules per kilogram-kelvin
• γ – Thermal expansion coefficient as 10⁻³ per kelvin
• λ – Heat conductivity in milliwatts per meter-kelvin
• η – Viscosity in micropascal-seconds (1 cP = 1000 μPa·s)
• σ – surface tension in millinewtons per meter (equivalent to dyn/cm)

Standard conditions

In the following table, material data are given for standard pressure of 0.1 MPa (equivalent to 1 bar). Up to 99.63 °C (the boiling point of water at 0.1 MPa), at this pressure water exists as a liquid. Above that, it exists as water vapor. Note that the boiling point of 100.0 °C is at a pressure of 0.101325 MPa (1 atm), which is the average atmospheric pressure.

 

Triple point

In the following table, material data are given with a pressure of 611.7 Pa (equivalent to 0.006117 bar). Up to a temperature of 0.01 °C, the triple point of water, water normally exists as ice, except for supercooled water, for which one data point is tabulated here. At the triple point, ice can exist together with both liquid water and vapor. At higher temperatures, the data are for water vapor only.

 

Saturated vapor pressure

The following table is based on different, complementary sources and approximation formulas, whose values are of various quality and accuracy. The values in the temperature range of −100 °C to 100 °C were inferred from D. Sunday (1982) and are quite uniform and exact. The values in the temperature range of the boiling point of water up to the critical point (100 °C to 374 °C) are drawn from different sources and are substantially less accurate; hence they should be used only as approximate values.^{[23][24][25][26]}

To use the values correctly, consider the following points:

• The values apply only to smooth interfaces and in the absence other gases or gas mixtures such as air. Hence they apply only to pure phases and need a correction factor for systems in which air is present.
• The values were not computed according formulas widely used in the US, but using somewhat more exact formulas (see below), which can also be used to compute further values in the appropriate temperature ranges.
• The saturated vapor pressure over water in the temperature range of −100 °C to −50 °C is only extrapolated [Translator's note: Supercooled liquid water is not known to exist below −42 °C].
• The values have various units (Pa, hPa or bar), which must be considered when reading them.

Formulas

The table values for −100 °C to 100 °C were computed by the following formulas, where T is in kelvins and vapor pressures, P_w and P_i, are in pascals.

Over liquid water

log_e(P_w) = −6094.4642 T⁻¹ + 21.1249952 − 2.724552×10⁻² T + 1.6853396×10⁻⁵ T² + 2.4575506 log_e(T)

For temperature range: 173.15 K to 373.15 K or equivalently −100 °C to 100 °C

Over ice

log_e(P_i) = −5504.4088 T⁻¹ − 3.5704628 − 1.7337458×10⁻² T + 6.5204209×10⁻⁶ T² + 6.1295027 log_e(T)

For temperature range: 173.15 K to 273.15 K or equivalently −100 °C to 0 °C

At triple point

An important basic value, which is not registered in the table, is the saturated vapor pressure at the triple point of water. The internationally accepted value according to measurements of Guildner, Johnson and Jones (1976) amounts to:

P_w(t_tp = 0.01 °C) = 611.657 Pa ± 0.010 Pa at (1 − α) = 99%

 

Magnetic susceptibility

Accepted standardized value of the magnetic susceptibility of water at 20 °C (room temperature) is −12.97 cm³/mol.^[27]

Accepted standardized value of the magnetic susceptibility of water at 20 °C (room temperature) is −0.702 cm³/g.^[27]

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• Except where noted otherwise, data relate to Standard temperature and pressure.
• Reliability of data general note.

See also

• Water portal

• Properties of water

References

1. "Thermophysical Properties of Fluid Systems". NIST Chemistry WebBook. National Institute of Standards and Technology. doi:10.18434/T4D303. NIST Standard Reference Database Number 69.
2. Lide 2004, p. 6-15.
3. Maksyutenko, Pavlo; Rizzo, Thomas R.; Boyarkin, Oleg V. (2006). "A direct measurement of the dissociation energy of water". The Journal of Chemical Physics. 125 (18): 181101. Bibcode:2006JChPh.125r1101M. doi:10.1063/1.2387163. PMID 17115729.
4. Cook, R; Delucia, F; Helminger, P (1974). "Molecular force field and structure of water: Recent microwave results". Journal of Molecular Spectroscopy. 53 (1): 62–76. Bibcode:1974JMoSp..53...62C. doi:10.1016/0022-2852(74)90261-6.
5. Hoy, AR; Bunker, PR (1979). "A precise solution of the rotation bending Schrödinger equation for a triatomic molecule with application to the water molecule". Journal of Molecular Spectroscopy. 74 (1): 1–8. Bibcode:1979JMoSp..74....1H. doi:10.1016/0022-2852(79)90019-5.
6. "List of experimental bond angles of type aHOH". Computational Chemistry Comparison and Benchmark DataBase.
7. Griffiths, David Jeffery (1999). Introduction to Electrodynamics (3rd ed.). Prentice Hall. p. 275. ISBN 978-0-13-919960-8.
8. "Water and the Speed of Sound". www.engineeringtoolbox.com. Retrieved 2008-04-29.
9. Dean & Lange 1999, p. 1199: Due to the old definition of liter used at the time, the data from the Handbook was converted from old g/ml to g/cm³, by multiplying by 0.999973
10. Franks 2012, p. 376.
11. Lide 2004, p. 6-201.
12. Dean & Lange 1999, p. 1663.
13. Revised Release on Viscosity and Thermal Conductivity of Heavy Water Substance, The International Association for the Properties of Water and Steam Lucerne, Switzerland, August 2007.
14. Dean & Lange 1999, p. 1436.
15. Dean & Lange 1999, p. 1476.
16. Martin Chaplin. "Water Phase Diagram". London South Bank University. Retrieved 2022-05-27.
17. Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. pp. 8–71, 8–116. ISBN 0-8493-0486-5.
18. Martin Chaplin. "Water ionization". London South Bank University. Retrieved 2022-05-27.
19. Martin Chaplin. "Water Absorption Spectrum". London South Bank University. Retrieved 2022-05-27.
20. Fulmer, Gregory R.; Miller, Alexander J. M.; Sherden, Nathaniel H.; Gottlieb, Hugo E.; Nudelman, Abraham; Stoltz, Brian M.; Bercaw, John E.; Goldberg, Karen I. (2010). "NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in Deuterated Solvents Relevant to the Organometallic Chemist" (PDF). Organometallics. 29 (9): 2176–2179. doi:10.1021/om100106e. ISSN 0276-7333.
21. Holz, Manfred; Heil, Stefan R.; Sacco, Antonio (2000). "Temperature-dependent self-diffusion coefficients of water and six selected molecular liquids for calibration in accurate 1H NMR PFG measurements". Physical Chemistry Chemical Physics. 2 (20): 4740–4742. Bibcode:2000PCCP....2.4740H. doi:10.1039/b005319h. ISSN 1463-9084.
22. "IAPWS". Main IAPWS Thermodynamic Property Formulations. Retrieved 4 May 2023. In 1995, IAPWS approved a new formulation of the thermodynamic properties of water and steam for general and scientific use. This replaced the 1984 formulation of Haar, Gallagher and Kell, and now serves as the international standard for water's thermodynamic properties.
23. Guildner, L. A.; Johnson, D. P.; Jones, F. E. (1976). "Vapor Pressure of Water at Its Triple Point: Highly Accurate Value". Science. 191 (4233): 1261. Bibcode:1976Sci...191.1261G. doi:10.1126/science.191.4233.1261. PMID 17737716. S2CID 37399612.
24. Klaus Scheffler (1981): Wasserdampftafeln: thermodynam. Eigenschaften von Wasser u. Wasserdampf bis 800°C u. 800 bar (Water Vapor Tables: Thermodynamic Characteristics of Water and Water Vapor to 800°C and 800 bar), Berlin [u.a.] ISBN 3-540-10930-7
25. D. Sonntag und D. Heinze (1982): Sättigungsdampfdruck- und Sättigungsdampfdichtetafeln für Wasser und Eis. (Saturated Vapor Pressure and Saturated Vapor Density Tables for Water and Ice)(1. Aufl.), VEB Deutscher Verlag für Grundstoffindustrie
26. Ulrich Grigull, Johannes Staub, Peter Schiebener (1990): Steam Tables in SI-Units – Wasserdampftafeln. Springer-Verlagdima gmbh
27. Weast, Robert (1983–1984). CRC, Handbook of Chemistry and Physics 64th edition. Boca Raton, Florida: CRC publishing. pp. E-119. ISBN 0-8493-0464-4.

Bibliography

• Dean, John Aurie; Lange, Norbert Adolph (1999). Lange's Handbook of Chemistry (15th ed.). McGraw-Hill. ISBN 978-0-07-016384-3.
• Franks, Felix (2012). The Physics and Physical Chemistry of Water. Springer. ISBN 978-1-4684-8334-5.
• Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD)
• Lide, David R. (2004). CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. ISBN 978-0-8493-0485-9.

External links

• Microwave Spectrum (by NIST)
• Water properties by Martin Chaplin, London South Bank University.