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Joined 2026-09-21 Message
Revised Release on Surface Tension of Ordinary Water Substance by International Association for the Properties of Water and Steam Created 2026-10-20 Updated 2026-11-05
Recommended experimental surface tension values and a temperature-dependent interpolating formula for liquid water in equilibrium with its vapour. Printed page 3 gives the formula and validity range; Table 1 starts on printed page 4.
Official release: iapws.org/technical-guidance/release/Surf-H2O
IAPWS R11-24, adopted June 2024. The International Association for the Properties of Water and Steam publishes the formulation.
Nomenclature and section 3 declare a dimensionless ionization constant, molal ionic standard states and a mole-fraction water standard state. Section 6, Table 3 gives temperature- and pressure-dependent values; the near-ambient 25-degree value is approximately ten to the minus fourteen.