92 



CONDUCTIVITY AND VISCOSITY OF SOLUTIONS 



The values for pure-water solutions were taken from the work of 

 West and Jones, 1 except those for 15. For this temperature they 

 were calculated by means of the equations 



for sodium iodide, and 



At, = 68.45 + 1 .883 + .00829* 2 



for potassium iodide. These equations apply only to the N/8 solutions, 

 every other dilution requiring a different equation. The accuracy with 

 which West and Jones's values fit the curve is worth noting. 



4.96% 



10.00 



20.00. 



50.26 

 60.34 

 70.42 

 80.51 



90.67 

 95.77 

 99.98 



10 



15 



25 

 Temperature 



FIG. 39. N/8 Nal. 



15 



25 



Temperature 

 FIG. 40. N/8 Nal. 



35" 



The decrease in conductivity just mentioned is very rapid in the 

 water end of the curve up to the 30 per cent alcohol, and from there on 

 it is much more gradual. We may conclude from this, either that 

 the first addition of alcohol to w r ater has a much more marked effect 

 on the association of the water than the addition of a little water to the 

 alcohol has on the association of the alcohol, or that comparatively 

 small quantities of alcohol increase the viscosity of water much more 

 markedly than is the case when small quantities of water are added to 

 alcohol ; or, again, that there is a sudden change in the hydration of the 

 dissolved substance caused by the addition of the alcohol, whereas 

 water has a far smaller effect on the alcoholation; or, finally, that 

 perhaps all or some of these factors combine to produce the effect. 

 Let us analyze them. 



l Amer. Chem. Journ., 34, 377 and 384 (1905). 



