CHAPTER VII. 

 CONDUCTIVITY OF CERTAIN ORGANIC ACIDS IN ETHYL ALCOHOL. 



BY H. H. LLOYD AND JOHN B. WIESEL. 



During the past six years a fairly thorough and systematic study of 

 the conductivity and dissociation of aqueous solutions of organic acids, 

 as affected by temperature and by dilution, has been in progress in 

 this laboratory. 1 Very little work had been done upon solutions of 

 organic acids in absolute ethyl alcohol (as will become evident from the 

 historical review that follows), and it was therefore decided to extend 

 our investigations into this field. 2 Accordingly, Wightman, Wiesel, 

 and Jones undertook a preliminary investigation of the problem, worked 

 out a fairly satisfactory method of procedure, and made conductivity 

 measurements of nine organic acids. 3 The present investigation is a 

 continuation and extension of their work. 



HISTORICAL SKETCH. 



The property of water, which, in the pure condition, conducts elec- 

 tricity only very slightly, to become conducting upon the addition of 

 many compounds which of themselves are non-conducting, was known 

 to De la Rive, and was the subject of interesting experiments by Fara- 

 day; and the fact that solvents other than water exhibit the same 

 phenomenon (of acquiring conductivity upon the addition of non- 

 electrolytes) has been studied by a large number of workers; 4 but to 

 Kohlrausch and Ostwald belongs the credit of having placed investi- 

 gations in this field once and for all upon a firm scientific basis. 



The contributions of Kohlrausch may be briefly described as follows : 

 (1) The development of a convenient and precise method for measuring 

 conductivity; 5 (2) the emphasis on and the determination of the 

 extent to which conductivity is influenced by temperature; (3) the 

 reduction of conductivity measurements to definite, fixed units; (4) the 

 reference of conductivity not to weight per cent, as had been previously 

 done, but to molecular volumes of solutions; that is, volumes which 

 contain equivalent amounts of the dissolved substances; 6 (5) the 

 enunciation of the law of the independent migration velocities of ions. 



Ostwald made the conductivity method of Kohlrausch more com- 

 plete and more practicable by reducing the apparatus and the manipu- 



iCarnegie Inst. Wash. Pub. No. 170, Part II (1912); No. 210, Chap. II (1915). 

 2 Amer. Chem. Journ., 44, 156 (1910); 46, 56 (1911); 48, 320, 411 (1912); 50, 1 (1913). 

 3 Journ. Amer. Chem. Soc., 36, 2243 (1914). Carnegie Inst. Wash. Pub. No. 210, Chap. Ill 

 (1915). 



4 Walden: Zeit. phys. Chem., 8, 433 ff. (1891); 46, 103 ff. (1903). 



6 Pogg. Ann., 138, 379 (1869); 159, 233 (1876); Wied. Ann., 11, 653 (1880); 26, 161 (1885). 

 8 Wied. Ann., 6, 145 (1879). 



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