180 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



In Table LXV are given values for the conductance of magnesium 

 nitrate hexahydrate in anhydrous propyl alcohol and in propyl alcohol 

 containing 0.7 per cent of water. 



The original salt having been hydrated, it is probable that the complex 

 hydrate was to some extent present in the solution. Nevertheless, the 

 value of the molecular conductance is of the same order of magnitude 

 as that of anhydrous calcium nitrate in propyl alcohol and the conduct- 

 ance curve is of the same general form. On the addition of water, the 

 conductance of the magnesium nitrate is markedly increased, particularly 

 in the more dilute solutions. The curve for the conductance in the 

 presence of water twice intersects the curve for the conductance in the 

 anhydrous solvent. This effect may in part be due to a change in the 

 speed of the ions, owing to the presence of water, and in part to a more 

 or less complex equilibrium which must exist between the dissolved 

 electrolyte and the water. 



Those salts which have only a slight tendency to form stable com- 

 plexes with water are, as a rule, ionized more highly in such solvents as 

 acetone and the alcohols than are salts which exhibit a pronounced ten- 

 dency to form stable complexes with water. Correspondingly, the addi- 

 tion of water to a solution of a salt, which has little tendency to form 

 complexes with water, has very little influence upon its ionization. The 

 effect is scarcely observable in solutions of such salts as potassium and 

 sodium iodides. In the case of lithium chloride dissolved in ethyl alcohol 

 there is a slight increase in the ionization upon the addition of water. 

 In Table LXVI are given values for the conductance of solutions of 

 lithium chloride in ethyl alcohol in the presence of water. 2 It is evident 

 from an inspection of this table that the conductance of lithium chloride 

 in ethyl alcohol is increased slightly upon the addition of water. The 

 effect is somewhat more marked at higher concentration. 



TABLE LXVI. 



CONDUCTANCE OF LiCl IN C 2 H 5 OH IN THE PRESENCE OF WATER AT 25. 







A 5 17 ' 7 



A J31.8 



Goldschmidt, Ztschr. /. phya. Chem. 89, 138 (1914). 



