Measurement of the Apparent Dissociation Constants of Carbonic Acid in Seawater at Atmospheric Pressure1

The apparent dissociation constants of carbonic acid in seawater were determined as functions of temperature (2–35°C) and salinity (19–43 ‰ ) at atmospheric pressure by measurement of K’x and the product K'� K'2. At 35%° salinity and 25°C the measured values were p K ′ 1 = 6.000 and p K ′ 2 = 9.115; at 35 ‰ and 2°C the measured values were p K ′ 1 = 6.177 and p K ′ 2 = 9.431.