250 REPORT— 1901. 



investigators as Ostwald and Bredig, we find that Ostwald gives 

 A'1024— A'32=10'lj whereas Bredig gives /ni(,24— ^'32=1^'9- 



When the hydrolysis is greater, however, an approximate idea of it 

 can be gained in this way from the conductivity. 



V. — Hydrolysis of the hydrochlorides of organic bases as determined from 



their electric conductivity. 



Temperaiure=:25°. 



Hydrolysis of Hydrocbloricle 

 x\ame of base. -^^ N ^^^^^.^^^^ 



Aniline 1'5 



o-Toluidine 1-8 



wi-Toluidine 1"3 



7;-Toluidine 9 



Beta'in 32'5 



VI. — Hydrolysis of inorganic salts (conductivity method). 

 Tem2)erature =25°. 



Hydrolysis 

 ^^^^' in Yo solution. 



AICI3 0-5 



BeSO^ 0-5 



PbClo 0-4 



UO.,(NO,) 0-G 



Hg(C10|), 6-3 



Much more might be added on the subject of electric conductivity as 

 applied to the determination of hydrolysis. Salts in which both the acid 

 and base are weak present quite a different aspect, but a discussion as to 

 their behaviour would lead us too far. 



To return to the other methods of estimation, a recent method should 

 be mentioned which differs from those depending on catalysis. We 

 have seen that when a salt such as aniline hydrochloride undergoes 

 hydrolysis two products result, the hydrochloric acid, strongly ionised and 

 .active, and the aniline, practically unionised and inactive. All the methods 

 that have been mentioned so far have depended on the measurement of 

 the strongly ionised component, either by its conductivity or by some 

 catalytic action which it brings about. 



Under some conditions these determinations become difficult to 

 carry out owing to the decomposition or precipitation of one of the 

 reaction products or from other causes. In these cases it is better to 

 measure the indifferent component. The method that suggests itself most 

 readily is that of extraction with some solvent which is insoluble in 

 water. The laws of distribution of a substance between two solvents are 

 well known, and by making use of these the hydrolysis can be easily 

 calculated from the amount of substance which is extracted. The 

 method was tested recently by Farmer ' in the following way. The salt is 

 dissolved in a known quantity of water and a known quantity of benzene 

 added. The whole is brought to constant temperature and shaken. The 

 amount of substance extracted by the benzene is then estimated, preferably 



' J.C.S.,19, 86 3(1901). 



