WORK OF J. SAM GUY. 



175 



It is also true that salts of approximately the same hydrating power show, in 

 glycerol, temperature coefficients of the same order of magnitude. 



The molecular conductivities at low dilutions in nearly every case are smaller for 

 ternary than for binary electrolytes, while at higher dilutions the reverse is true 

 without exception. This may be due to the fact that glycerol is only a fair dissociat- 

 ing agent, resembling methyl and ethyl alcohols, and has, at moderate concentra- 

 tions, the power of producing only two ions from a ternary electrolyte, or at least 

 dissociating a ternary electrolyte only to a moderate extent. 



We should expect to find the ternary electrolytes yielding more ions at higher dilu- 

 tions, and, hence, showing a greater molecular conductivity than binary electrolytes 

 under the same conditions. That this is true may be best shown by comparing the 

 molecular conductivities of several of the binary and ternary electrolytes used. 



In table 125 the molecular conductivities of several typical salts at 25 are 

 compared at volumes 10 and 1,600, respectively. These data confirm the above 

 statement that while at low dilutions a ternary electrolyte usually has the smaller 

 molecular conductivity, at higher dilutions the reverse is usually true. 



Table 125. Molecular Conductivities of Several Salts. 



Table 116 gives the molecular conductivities and temperature coefficients of con- 

 ductivity of all the salts studied at 55, 65, and 75. The same general relations 

 hold at these temperatures as at the lower temperatures, viz, a regular increase in 

 conductivity with increased dilution and rise in temperature; and a more marked 

 increase, or a larger temperature coefficient, with those salts which in aqueous solu- 

 tions possess the greatest power of hydration. The same reasoning employed above 

 for the lower temperatures is applicable here. 



Table 117 contains the data for the molecular conductivity and temperature 

 coefficients of conductivity, at 25, 35, and 45, in per cent and in conductivity 

 units, for potassium chloride, sodium nitrate, ammonium bromide, and strontium 

 chloride in the various mixtures of glycerol with water, methyl alcohol, and ethyl 

 alcohol. The results are plotted in figs. 70 to 79, inclusive. 



These curves show that the conductivities in such mixtures do not follow the law 

 of averages, but are always less. In every case there is a marked sagging of the 

 curves, but in no instance was a minimum obtained. This deviation from the law ' 

 of averages has been explained by the work of Jones with Lindsay and Murray. 

 When glycerol is mixed with water, or with either of the alcohols, it is clear that the 

 properties of the mixture are not additive, the one solvent tending to lessen the asso- 

 ciation of the other; and, hence, their combined power of dissociating electrolytes is 

 less than would be expected if there were no such lowering of each other's association. 



