130 Scientific Proceedings (112). 



Table of Dissociation Constants. (Calculated Mid-point p h .) 







Percentage In- 



Scale' 









Indicator, 



Solvent 



die 21 tor in Finsl 

 Solution. 



Reading. 



p 



K. 



Mean 



Brom phenol blue. . . . 



Alcohol 



0.0004 



27.I 



3-52 



3-95 











41.4 



3-72 



3-85 











52.8 



3-94 



3-89 











67.2 



4.16 



3-85 











78.7 



4.40 



3-83 



3.87 



Methyl red 



Water 



0.0004 



300 



4-6S 



5.02 











38.5 



4.82 



5-02 











50.0 



S-03 



503 











58.6 



5-19 



5-04 











61.4 



5-22 



5.02 











64-3 



5-26 



5.00 











72.9 



5-41 



4.98 











75-6 



5-50 



499 











81.5 



5-65 



500 



5-01 



Brom cresol purple. . . 



Alcohol 



0.0012 



27.1 



5.83 



6.26 











38.5 



6.02 



6.22 











47.2 



6.22 



6.27 











55-7 



6.44 



6.30 











64-3 



6-59 



6-33 



6.28 



Brom thymol blue . . . 



Water 



0.0004 



24.2 



6.59 



7.09 











35-7 



6.83 



7.09 











47.2 



7.03 



7.08 











55-7 



7.19 



7.09 











67.1 



7-37 



7.06 











75-6 



7-56 



7.06 











81.5 



7-75 



7.09 



7.08 



Phenol red 



Water 



O.OOO4 



18.5 



7.12 



7-77 











30.0 



7-37 



7-74 











38.5 



7.56 



7.76 











49.0 



7-74 



7-77 











58.6 



7-93 



7.78 











70.0 



8.16 



7-79 











81.5 



8-43 



7.78 



7-77 



Cresol red 



Water 



0.0004 



30.0 



7-74 



8. n 











35-7 



7.91 



8.17 











47.2 



8.15 



8.10 











58.6 



8.28 



8.13 











64-3 



8-39 



8.13 











71-5 



8.52 



8.12 



8.13 



Thymol blue 



Water 



0.0004 



15-7 



8.10 



8.83 











18.5 



8.17 



8.83 











30.0 



8.44 



8.87 











35-7 



8-54 



8.80 











44-3 



8.78 



8.89 











58.6 



9.01 



8.86 











75-6 



9-43 



8-93 



8.86 



1 The actual readings in this column were made on a centimeter scale, and are 

 here converted to per cent. 



