CHAPTER III. 



A PRELIMINARY STUDY OF THE CONDUCTIVITY OF CERTAIN 

 ORGANIC ACIDS IN ETHYL ALCOHOL AT 15, 25, AND 35. 



BY E. P. WlGHTMAN AND J. B. WlESEL. 



Considerable work has been done, in the Chemical Laboratory of 

 the Johns Hopkins University, especially within the last five years, 

 on the conductivity and dissociation of organic acids in water as a 

 solvent, over a fairly wide range of temperature and dilution; and a 

 number of interesting relationships have been pointed out. 1 Since, up to 

 the present, almost nothing has been done with these acids in absolute 

 alcohol, we decided to extend our investigations on the organic acids 

 into this field. 



HISTORICAL. 



A few rather crude measurements of the conductivity of hydrochloric 

 acid and some inorganic salts had been made in alcohol-water mixtures 

 as early as 1882. The first work which need be mentioned is that of 

 Kablukoff 2 in 1889. He determined the conductivity of hydrochloric 

 acid in alcohol and some other solvents, and in mixtures of alcohol and 

 water, and showed that molecular conductivity increased markedly with 

 decrease in amount of alcohol and increased slowly with the dilution. 



Wakeman, 3 in 1893, measured the conductivities of some organic 

 acids, as well as of hydrochloric acid, potassium chloride, and sodium 

 chloride, in mixtures of alcohol and water ranging from pure water to 

 50 per cent alcohol. Using Lentz's 4 values for the relative migration 

 velocities of hydrogen, sodium, and potassium in water and mixtures 

 of water and alcohol, and employing the method of Ostwald 5 for 

 determining the // values for the organic acids from their sodium 

 salts, he calculated the dissociations of these acids. He also calculated 

 dissociation constants by means of Ostwald's dilution law. His dis- 

 sociation values decrease slowly with increase in alcohol. The con- 

 stants decrease much more rapidly for the same increase in alcohol. 

 Wakeman plotted curves (fig. 21) with molecular conductivities as 

 ordinates and percentage alcohol as abscissae, and showed that when 

 they were extended beyond 50 per cent alcohol in the direction of 100 

 per cent alcohol, the conductivity probably approached zero as a limit. 

 He concluded that dissociation in the mixtures is much less than would 



Publication 170, Part II, Carnegie Inst. Wash.; see also Amer. Chera. Journ., 44, 156 (1910) ; 



46, 56 (1911); 48, 320, 411 (1912); 50, 1 (1913). 

 2 Zeit. phys. Chem., 4, 429 (1889). 

 3 Ibid., 11, 49 (1893). 



4 Mem. de 1'Acad. de St. Petersb., VII series, vol. 30, 9 (1882). 

 6 Zeit. phys. Chem., 2, 270 (1888); ibid., 3, 170 (1889); see also, Amer. Chem. Journ., 46, 60 (1911). 



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