Chapter V. 



The Conductance of Solutions as a Function of 

 Their Viscosities. 



1. Relation Between the Limiting Conductance A and the Viscosity 

 of the Solvent. One of the factors upon which the conductance of a 

 solution depends is the viscosity of the solution itself. If conductance 

 is due to the motion of charged particles through a medium, then the 

 speed of the particles will obviously depend upon the resistance which 

 the particles experience in their motion; that is, upon the viscosity of 

 the medium. Unless the solutions are concentrated, their viscosities will 

 not differ materially from that of the pure solvent. We should therefore 

 expect that the viscosity of the pure solvent would determine the motion 

 of particles under otherwise given conditions. We shall accordingly 

 examine the relation between the conductance and the viscosity of solu- 

 tions in different solvents. In very dilute solutions we may expect that 

 the motion of a given particle will be practically independent of that of 

 other particles of the electrolyte which may be present in the solution. In 

 the limit, therefore, the A values will be determined by the nature of the 

 moving particles and by that of the solvent medium in which they move. 

 In Table XXXIX 1 are given fluidity and A values for solutions in a 

 number of solvents, together with the values of the ratio A /F. 



TABLE XXXIX. 

 FLUIDITY AND A VALUES FOR ELECTROLYTES IN DIFFERENT SOLVENTS. 



Solvent 



Water 



Ammonia 



Sulphur dioxide 

 Benzonitrile . 



Temp. 



18 



33 



10 



25 



Epichlorohydrin 25 



Propylalcohol 18 



Acetone 18 



Methylethylketone 25 



Pyridine 18 



Isobutylalcohol 25 



Acetoaceticester 18 



Isoamylalcohol 25 



Ethylenechloride 25 



1 These values are taken from Kraus and Bray (Zoo. cit., p. 1383), excepting those for 

 water and the viscosity data for sulphur dioxide for which see Fitzgerald, J. Phya. Chem. 

 16, 621 (1912). 



109 



