1908-9.] Hydrolysis of Salts of Amphoteric Electrolytes. 649 
Ortho-amidobenzoic acid was chosen as the most convenient example 
of an amphoteric base whose hydrolysis in acid solution was neither too 
great nor too small at the temperature and dilutions examined, and 
therefore most typical of the class. 
Electrical Conductivity. 
The conductivity experiments were all carried out in a thermostat 
at 25° C. The water used was distilled in the open air, using a block tin 
condenser, and its conductivity at 25° varied from *8 to 1*3 X 10 -6 . 
The degree of hydrolysis, x, was obtained from the formula x = — — / 
Mhci Mv 
where M v is the observed molecular conductivity and ju v the molecular 
conductivity of the unhydrolysed salt. 
The values for ju v were taken from Winkelblech. His numbers in 
Siemens mercury units were recalculated into reciprocal ohms. 
V. 
fX V ' 
16 
102-6 
32 
106-8 
64 
109-9 
128 
113-2 
256 
115-4 
. . N 
The values for ju HC1 were found by experiment. The original solution 
for each set of observations was made up by weighing out the required 
amount of o-amidobenzoic acid, adding the corresponding quantity of 
N . . N . 
— HC1, of which a large stock was kept, and making up to -- with con- 
8 16 
ductivity water. The subsequent dilutions were sometimes carried out by 
means of Arrhenius’ pipettes, sometimes by mixing equal quantities of 
water and solution in resistance-glass bottles. 
V. 
MHCI]. 
ftv. 
M, 
X. 
k b ( 1 - x)v 
K" a* 
Winkelblech. 
16 
392 
102-6 
173-6 
•245 
201 
32 
400 
106-8 
207-2 
•34 
180 
177 
64 
407 
109-9 
246-7 
•46 
163 
164 
128 
413 
1132 
288-0 
•58 
158 
155 
256 
417 
115-4 
327T 
•70 
155 
150 
* Bredig, Zeit. Physikal. Chem., vol. xiii. p. 321. 
