72 



HYDROGEN ION CONCENTRATION 



TABLE 14 

 Table of dissociation constants of amphoteric electrolytes at 25° 

 The isoele ctric point values in this table were calculated from the equation 



I = ,— ; , on the assumption that k„ = 10 ~". 



Arginine, 2nd 



stage 



Arginine, 1st 



stage 



Lysine, 2nd 



stage 



I/ysine, 1st 



stage 



Leucine 



GlycocoU 



Alanine 



Histidine, 2nd 



stage 



Histidine, 1st 



stage 



Phenylalanine 



Tyrosine 



Leucylgh^cine 

 Alanylgh^cine 

 Glj^cylglycine 

 Aspartic acid. 



Arsenious 



acid 



o-Aminoben- 



zoic acid . . . 

 p-Aminoben- 



zoic acid . . . 



m-Aminoben- 

 zoic acid . . . 



kb 



Observer 



<1.1 X 10-14 



1.0 X 10-1- 



1.8 X 10-10 



1.8 X 10-1" 



1.9 X 10-i» 



2.2 X 10-9 



2.5 X 10-9 



4.0 X 10-9 



1.5 X 10-8 



1.8 X 10-8 



1.8 X 10-8 



1.5 X lO-" 



6 X 10-i« 

 1.06 X 10-5 

 1.21 X 10-5 



1.6 X 10-5 



2.2 X 10-12 



1.0 X 10-^ 



1.1 X 10-12 



<1.1 X 10-^ 



2.3 X 10-12 

 2.7 X 10-12 



5.1 X 10-12 



5.0 X 10-13 



5.7 X 10-9 



1.3 X 10-12 



2.6 X 10-12 



3.0 X 10-1' 



2.0 X 10-11 



2.0 X 10-11 



1.2 X 10-12 



1 X 10-1" 

 1.37 X 10-12 

 2.33 X 10-11 



1.20 X 10-12 



Kanitz 



Kanitz 



Kanitz 



Kanitz 

 Winkelblech 

 Winkelblech 

 Winkelblech 



Kanitz 



Kanitz 

 Kanitz 

 Kanitz 

 Euler 

 Euler 

 Euler 



Winkelblech, 

 Lunden 



Wood 



Lunden 



Winkelbech, 

 Walker 



Winkelbech, 

 Walker 



Isoelectric point 



ca. 3 X 10-11 



ca. 3 X lO-i" 

 8.8 X 10-7 

 8.2 X 10-7 

 6.1 X 10-7 



6.2 X 10-8 

 4.4 X 10-6 

 3.9 X 10-s 

 2.2 X 10-« 



3.0 X 10-« 



1.1 X 10-3 



2.4 X 10-5 

 2.8 X 10-1 

 7.2 X 10-3 



l.l X 10-" 



