230 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



bases or Weaker acids. 5 A considerable number of equilibria of this type 

 have been investigated and, in general, the results confirm the assump- 

 tion that the strong base or acid is distributed between the weaker acids 

 or bases in conformity with the law of mass-action. 



Equilibria similar to hydrolytic equilibria in aqueous solutions have 

 been found to exist in solutions in non-aqueous solvents. Such equi- 

 libria are to be expected in the case of all distinctly acid solvents which 

 are capable of yielding a hydrogen ion. This, therefore, includes solu- 

 tions in all acids, such as hydrocyanic acid, formic acid, acetic acid, etc. 

 It likewise includes solutions in hydrogen derivatives whose acid prop- 

 erties are extremely weak, such as ammonia, for example. 



Franklin 6 has shown that equilibria of the hydrolytic type exist in 

 solutions in liquid ammonia. In the case of salts of very weak bases, 

 such as mercury for example, ammono-basic salts are precipitated when 

 the neutral salt is dissolved. These precipitates are redissolved on the 

 addition of an acid, while precipitation is facilitated by the addition of 

 an ammono-base, such as potassium amide. While equilibria of the 

 hydrolytic type thus exist in ammonia solutions, the evidence indicates 

 that it is only in the case of extremely weak bases that hydrolysis takes 

 place to an appreciable extent. The concentration of hydrogen ions in 

 ammonia is without doubt of an exceedingly low order. This is indicated 

 by the fact that salts whose ammono-bases are practically insoluble in 

 liquid ammonia, such as calcium and barium nitrates, for example, yield 

 clear solutions when dissolved in ammonia, even at high concentrations. 

 Furthermore, as is well known, solutions of the alkali metals, as well as 

 of metals of the alkaline earths, in liquid ammonia, are comparatively 

 stable. It is to be expected that such would not be the case if the con- 

 centration of tjhe hydrogen ions were appreciable. 



Schlesinger 7 has shown that solutions of salts in formic acid are 

 appreciably hydrolyzed. He found that on passing a current of air 

 through solutions of chlorides in formic acid free hydrochloric acid is 

 carried over. That hydrolysis may occur in solutions in other solvents, 

 such as hydrocyanic acid, for example, is indicated by the high value of 

 the residual specific conductance of the pure solvents. It is, of course, 

 possible that in these cases the conductance is in a measurable degree 

 due to the presence of impurities, but the high value obtained in many 

 instances is probably due to the presence of hydrogen ions. It is prob- 

 able, moreover, that the higher the dielectric constant of the medium, the 

 greater the concentration of hydrogen ions due to the solvent. No 



Thiel and Roemer, Ztschr. f. phys. Ohem. 61, 114 (1908). 

 Franklin, J. Am. Chem. 8oc. 7, 820 (1905). 

 Schlesinger, J. Am. Chem. Soc. 33, 1932 (1911). 



