CARBON DIOXIDE-WATER EQUILIBRIUM 



177 



Table 8.IV 



Equilibrium Concentrations in Carbonic Acid Solutions at 0° C. 



(from Faurholt 1924) 



Table 8. V shows the concentration of the species CO2 in the carbonate- 

 bicarbonate buffer mixtures, which were first used in the study of photo- 

 synthesis by Warburg (1919), and found many appHcations, particularly 



100 

 % 



80 



60 



40 



20 



7 



13 



Fig. 17. — Distribution of carbonic acid between 

 CO2, HCOs" and CO3 as a function of pH (0° C, ionic 

 strength 0) (after Faurholt 1924^). 



in kinetic investigations. The presence of a large quantity of bicarbonate 

 ions has the effect of stabilizing the concentration of the carbon dioxide 

 molecules and thus preventing a local exhaustion of carbon dioxide dur- 

 ing intense photosj^nthesis. 



