CARRIERS IN ELECTROLYTIC SOLUTIONS 207 



assume that, in the case of the hydrogen and the hydroxyl ions in water, 

 an interchange takes place between the ions and the solvent molecules 

 with the result that the mean path over which these ions travel is reduced 

 in proportion to the effective diameter of the solvent molecules which are 

 concerned in the interchange. A priori, there is nothing to indicate that 

 this hypothesis may not be correct. If it is correct, however, it must 

 lead to certain definite consequences which we may now examine. 



In the first place, it is to be expected that a similar phenomenon will 

 be found in solutions in non-aqueous solvents which are capable of 

 furnishing ions. In the case of liquid ammonia an equilibrium. exists of 

 the type: 



or, perhaps, 



2NH 3 = NH 2 - 



where NH 4 + is the ammonium ion and NH 2 " is the basic ion of liquid 

 ammonia. That such an equilibrium exists, is indicated by the fact that 

 certain ammonolytic equilibria exist in ammonia solutions comparable in 

 all respects with hydrolytic equilibria in aqueous solutions. 9 On the 

 basis of the above hypothesis, we should expect that the ammonium ions 

 and the NH 2 ~ ions would exhibit an exceptionally high conducting power 

 in liquid ammonia solutions. As may be seen by referring to the table 

 of ionic conductances in Chapter II, the amide ion in liquid ammonia 

 possesses a conducting power markedly lower than that of typical nega- 

 tive ions, while the conductance of the ammonium ion is distinctly lower 

 than that of the potassium ion. It follows, therefore, that in ammonia 

 solutions the ammonium and the amide ions are in no wise exceptional. 

 It has been maintained that the conductance of the alcoholate ion in the 

 alcohols is abnormally high. According to the best data available, how- 

 ever, the conductance of the alcoholates in alcohol 10 is of the same order 

 as that of typical salts in these solvents. 



As a result of conductance and transference measurements with the 

 formates in formic acid it has been shown that the formate ion in formic 

 acid possesses an exceptionally high conducting power. While the pre- 

 cise values are somewhat uncertain, roughly, the ionic conductances of 

 the sodium, potassium and formate ions in formic acid at 25 are 14.6, 

 17.5 and 51. 6. 11 The limiting value of the conductance of hydrochloric 

 acid in formic acid is approximately 75, compared with the value 69.4 12 



Franklin, J. Am. Chem. Soc. 27, 820 (1905). 



"Robertson and Acree, Intern. Congr. Appd. Chem. [8] 26, 609 (1912). 



11 Schlesinger and Bunting, J. Am. Chem. Soc. 41, 1934 (1919). 



Schlesinger and Martin, J. Am. Chem. Soc. 36, 1618 (1914). 



