The Carbonic Acid-carbonate Equilibrium and Other Weak Acids in Sea Water

Sea water is a salt solution of about 3.5 per cent concentration whose various constituents are maintained in almost constant proportions. A notable exception to these constant relations occurs in the case of carbon dioxide, which is found to vary greatly in concentration. These facts of variation arc undoubtedly related to the conditions of organic activity, and the concentration of carbonic acid is one determining factor for photosynthesis and an indicat,ion of energy releasing metabolic processes (Henderson, 1913; McClcndon, 1918). A pure carbonate solution is determined in its characteristics by three factors of base and hydrogen ion concentration and carbon dioxide tension. According to the work of Johnston (1916), start.ing with the condition