363 



these ions being further split up according to reaction II. 



A corrected value for «, is obtained, from which k, may be 

 calculated. 



In this way k, is found to be for the sulphonacetic acid : 



V = J 6 32 64 128 256 512 1024 



k,= 11.3 10.1 9.2 8.6 8.0 7.6 7.3 X 10-» 



and for the sulphonpropionic acid: 



V = 16 32 64 128 256 512 1024 



k, z= 7.8 7.0 6.3 5.8 5.3 5.2 4.8 X lO"» 



The mean value of the second dissociation constant thus becomes 

 for the sulphonacetic acid 8.9 X 10—-^ and for the sulphonpropionic 

 acid 6.0 >; 10-5. 



In this statement of views no account is taken of the combi- 

 nation of the ions H ' and HA', as shown by reaction III. 



A correction for this last, however, that would somewhat increase 

 the second dissociation constant is of no value for these strongly 

 dissociated acids, as the uncertaintj' in the values of the conductivity 

 of the ditFerent ions has a greater influence. 



Dr. 0. Ringer and Drs. D. W. Dijkstra have given their assistance 

 with some of the measurements. 



A more detailed account will appear in the Recueil d. trav. chim. 



Organic Chemical Laboratory of the university. 

 Groningen, 8^'' Sept. 1922. 



