66 CONDUCTIVITIES OF ORGANIC ACIDS 



days. On washing with alcohol and drying, it was found that the 

 alcohol which was in contact with the platinum electrodes was oxid- 

 ized by the air, even when this was thoroughly purified and dried, to 

 acetic acid, which, of course, increased the conductivity of the alcohol. 

 Therefore, instead of drying after washing with water and draining, 

 alcohol was introduced so as first to wash the glass walls, and then the 

 alcohol was allowed to cover the electrodes. Some of this alcohol was 

 then drawn off by means of a pipette and fresh alcohol was introduced, 

 keeping the electrodes continuously covered, until all the water had 

 been eliminated and the conductivity values after each removal and 

 addition of fresh alcohol remained unchanged. Says Wildermann, " this 

 cost a half day of work and 300 to 500 c.c. of good absolute alcohol." 

 The same procedure was adopted for dilute solutions of the acids, the 

 strength of any solution being determined by titration. He does not 

 give any tables of his results with the weaker acids acetic, mono- 

 chloracetic, and succinic. He simply makes the qualitative statement 

 that these substances between volumes 10 and 160 give a molecular 

 conductivity which increases approximately proportional to the square 



root of the volumes; that is ^!L is about equal to ,. / , v being the 



greater of the two volumes. 



Wildermann draws the following conclusions: 



"(1) Under about 10 liters for dichloracetic acid, the values of are 

 less than those of */ J above about 10 liters the value of - is 



_ \ Mr 



greater than */ > in dilutions from 800 to 2,000 liters the values of 



become almost equal to The increase of is therefore con- 

 Mo V MB 



tinuous, not only in the concentrated solutions, but also in the more 

 dilute solutions to which the equation ^ ~v=k may be applied." 



Me 



"(2) The same conclusions are even more nearly true in the case of 

 /3-resorcylic acid." 



(3) In the case of trichloracetic acid there is, just as above, an increase 



in from 20 to 300 liters, above which the value becomes almost 



equal to p. and then increases throughout the more dilute solutions. 



\v 



That this is true, even at a different temperature from 18, is shown 

 in some later work by the author, using an entirely independent method. 

 An explanation, however, had already been offered for the phenomenon 



