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). 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 •
cp –
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 c
P = 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 M
Pa (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. 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,
Pw and
Pi, are in
pascals.
Over liquid water :loge(
Pw) = −6094.4642
T−1 + 21.1249952 − 2.724552×10−2
T + 1.6853396×10−5
T2 + 2.4575506 loge(
T) For temperature range: 173.15 K to 373.15 K or equivalently −100 °C to 100 °C
Over ice :loge(
Pi) = −5504.4088
T−1 − 3.5704628 − 1.7337458×10−2
T + 6.5204209×10−6
T2 + 6.1295027 loge(
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: :
Pw(
ttp = 0.01 °C) = 611.657
Pa ± 0.010
Pa at (1 −
α) = 99% : == Magnetic susceptibility ==