Conductivity of Organic Acids in Ethyl Alcohol. 139 



DISCUSSION OF THE RESULTS. 



The most striking feature of the conductivities of the organic acids 

 in alcohol, as shown by an examination of table 75, is their extremely 

 small value. Wakeman, 1 in the course of his work on alcohol-water 

 mixtures, plotted curves of conductivity of the organic acids against 

 percentage alcohol, and, on extending the curves in the direction of 

 100 per cent alcohol, found that they apparently approached zero con- 

 ductivity as a limit. As can be seen from our results, the conduc- 

 tivities do not actually approach zero, but they never exceed 2, and 

 in the great majority of cases fall below unity. On account of the 

 extremely high resistances offered by alcoholic solutions of the organic 

 acids, Wildermann abandoned the Kohlrausch method as a means of 

 studying the conductivity of these solutions. The difficulty which he 

 experienced was obviated by the authors, by the use of cells with much 

 smaller constants than those he employed. Even with this improve- 

 ment, it was found necessary to discard all of the very weak organic 

 acids, such as the members of the acetic-acid series. 



The conductivities of the organic acids in alcohol are several hundred 

 times smaller than the conductivities of the same acids in water. When 

 we consider the fact that alcohol has from one-fourth to one-fifth the 

 dissociating power of water, as shown by the dissociation of strong 

 electrolytes in these solvents, the above fact does not at present seem 

 to admit of any very satisfactory explanation. 



The percentage temperature coefficients of conductivity vary from 

 2.5 to 4 per cent, and decrease with rise in temperature. They are uni- 

 formly higher than the corresponding values in aqueous solutions, 

 which range from 1 to 2.5 per cent. In the light of the work that has 

 been done in this laboratory, these results suggest the following 

 possibilities : 



(1) It might be that there is greater alcoholation in alcoholic solution 

 than hydration in aqueous solution, and that the amount of alcohola- 

 tion decreases with rise in temperature. This view, however, is not 

 substantiated by previous experiences. The alcoholates may be more 

 unstable with rise in temperature than the hydrates, but alcohol seems 

 in general to have far less power to combine with dissolved substances 

 than water. 



(2) If the temperature coefficient of fluidity of alcohol were greater 

 than that of water, the ions in alcoholic solutions would have greater 

 freedom of movement than in aqueous solutions. This would account 

 for the larger temperature coefficients of conductivity in alcoholic 

 solutions. Unfortunately, such is not the case. The temperature 

 coefficient of fluidity of water is greater than that of alcohol, as can 



l Zeit. phys. Chem.,11, 49 (1893) ; Ibid., 14, 247 (1894). 



