DISSOCIATION IN NON-AQUEOUS SOLUTIONS 151 



But also the hydrolysis of this salt is much greater in oil than it is 

 in water. The greater part of the acid and of the base persist along- 

 side of each other. This can be seen from the following: 



When we add more base to a mixture of much acid and little base, 

 then we should expect that the conductivity would rise in proportion 

 to the added base, if the latter was completely utilized for salt 

 formation. But it is observed that the conductivity increases less 

 than expected. Consequently, it must be assumed that the base 

 was not completely used up for the formation of salt, i.e., that the 

 salt remains extensively hydrolyzed, even in the presence of an 

 excess of acid. 



As experimental proof for this view the following observations 

 made by Beutner may be quoted: 



1 M solution of salicylic acid in nitrobenzene 

 showed at a high temperature (not so 

 soluble in the cold) a conductivity of 

 3.5 reciprocal megohms; calculated for 

 room temperature 2 recipr, megohms 



1 M solution of dimethyltoluidine in nitro- 

 benzene 0.1 recipr. megohms 



1 M solution of salicylic acid + 1 M dimethyl- 

 toluidine in nitrobenzene 430 recipr. megohms 



1/25 M solution of salicylic acid + 1/100 M 



dimethyltoluidine in nitrobenzene 18.5 recipr. megohms 



1/25 M salicylic acid + 1/50 M dimethyl- 

 toluidine in nitrobenzene 23.8 recipr. megohms 



(instead of 37, as it should have been, if all the base added 

 were used for salt-formation) 



1/25 M salicylic acid + 1/25 M dimethyltolui- 

 dine in nitrobenzene 27. 5 recipr. megohms 



(instead of 74) 



A quantitative utilization of these figures in the calculation of 

 dissociation constants can not unfortunately be carried out, for 

 Ostwald's dilution law, i.e., the mass law, is not vahd for electrolyte 

 solutions in oils on grounds which are as yet to be worked out. This 

 is probably due to molecular associations or aggregates, which 

 electroneutral molecules tend so strongly to form. 



A second difference is in the fact that in oily solutions there are 

 no acids or bases which are as strongly dissociated as the salts: 

 there are no "strong" acids and bases. Here we have only weak 

 electrolytes — namely all salts, and extremely weak electrolytes — 

 namely, all acids and bases. 



