Abstract
The stability constantK 1of the equilibrium NH 3 +H+⇌NH +4 was determined by potentiometric titration in synthetic seawaters of 5 to 40‰ (per mille) salinity and sodium chloride solutions between 0.2 and 0.7M ionic strength at temperatures of 5, 15 and 25°C. Moreover,K 1was determined in sulfate-free seawater of 35‰ salinity and 25°C. The dependence of logK 1on salinity (or ionic strength) and temperature can be reasonably well described by linear relations. TheK 1obtained for sulfate-free seawater agrees very well with earlier experimental results and theoretical predictions. From the measuredK 1and literature data on the equilibrium NH 3 (atm)⇌NH 3 (aq., NaCl), the atmospheric concentration of ammonia at equilibrium with seawater was estimated.
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Johansson, O., Wedborg, M. The ammonia-ammonium equilibrium in seawater at temperatures between 5 and 25°C. J Solution Chem 9, 37–44 (1980). https://doi.org/10.1007/BF00650135
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DOI: https://doi.org/10.1007/BF00650135