66 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



It is evident that the conductance of an ion is a function of the con- 

 stitution of the solvent as well as of that of the ion itself. In this con- 

 nection it should be observed that a given electrolyte dissolved in two 

 different solvents does not necessarily yield the same ions. In other 

 words, complexes may be formed between the ions and the solvent proper- 

 ties of which will depend upon the nature of the solvent. It -is well 

 known that certain ions tend to form complexes with certain solvents. For 

 example, the silver ion forms a complex with ammonia even in aqueous 

 solutions. It may be assumed, therefore, that the silver ion has a great 

 tendency to form complexes with ammonia. The cause for the relatively 

 low value of the conductance of the silver ion in ammonia may be 

 ascribed to the formation of a relatively large complex silver-ammonia 

 ion in ammonia solution. Similarly, those ions whose salts show a 

 marked tendency to form complexes with water, which, for example, 

 give stable crystalline hydrates, show a relatively higher speed in am- 

 monia than in water. Thus, the speed of the lithium ion in ammonia is 

 relatively much greater with respect to its speed in water than is that 

 of the potassium ion. We may therefore conclude that the lithium ion 

 is relatively less complex in ammonia than it is in water. 



