RELATIVEDETERMINATIOX OF SORETCOEFFICIEKTS OF ELECTROLYTES
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Relative Determination of Soret Coefficients of Electrolytes
by Toshio Ikeda and Hiroyuki Kimura Department of Chemistry, Shizuoka Cninersdy, Shizuoka, J a p a n
(Received March 90,1964)
From the thermoelectric power of an electrolytic thermocouple of a convenient type, the Soret coefficient was determined for six uni-univalent electrolytes at 25' and 0.01 M upon taking potassiuni chloride as a reference material. Our results were in fair agreement with the best values reported so far.
During the past ten years, the Soret coefficients of electrolytes have become measurable by a direct method1-8 with considerable accuracy. Recently, Turner and his co-workersJ have succeeded in the direct determination of the Soret coefficients for a nuiiiber of electrolytes by the conductometric method with reasonable accuracy, and they also succeeded in compiling the conventional ionic heats of transfer for a nuiiiber of ion species in good harmony with the Soret coefficients which they had determined. On the other hand, one of the present writersgaand Haase and his co-workersgb have indicated rwently some indirect ways of deterniining the Soret coefficients from the initial thermoelectric powers of thermocells. S o w , an alternative niethod niay be possible along similar lines when an electrolytic thermocouple of a convenient type is used. An experiment by this method will be reported in the present paper. The principlelo of this niethod was suggested by the Eastman school" and was used by Tyrrell and his oo-worliers.12 However, they used nierely the data on separate thermocells, without reference to the combined thermocells or such an "electrolytic thermocouple" as will be reported below. Our method of using the electrolytic theriiiocouple might be more advantageous in realizing the principle under identical experiinental conditions than one using separate therniocells
General Let us consider an electrolytic thermocouple of the syst eni
Hg-HgC1, I
