II. ON THE DETERMINATION OF THE FRKEZING-POINT DEPRES- 

 SIONS OF DILUTE SOLUTIONS OF ELECTROLYTES BY 

 THOS. C. HEBB, M. A., Dalkousie College, Halifax, N. S. 



(Read March 10th, 1001.) 



Dr. MacGregorhas shown,* that, if for any electrolyte curves 

 be plotted using ionization coefficients as ordinates and the 

 equivalent depressions of different observers as abscissae, the 

 curves so drawn diverge, as dilution increases, some to the right 

 and some to the left of what their general course is at moderate 

 dilution. He has also shown, that this tendency to diverge is 

 less for the results of Archibald and Barnes, both of whom 

 worked in the Dalhousie Physical Laboratory. This indicates 

 that the method they adopted was free from some source or 

 sources of error which affected the methods of other observers. 

 As they had not carried their observations to solutions of great 

 dilution, he suggested that 1 should go over the ground with 

 one or two electrolytes and see if, for higher dilutions, their 

 results were borne out. This I have done for potassium 

 chloride with the results given below. 



I chose this electrolyte for the following reasons: (1) It is 

 one of the salts for which Whethamf has made determinations of 

 the ionization coefficients for dilute solutions at 0C. ; (2) The 

 rightward or leftward tendency, above mentioned, is most 

 marked for this electrolyte ; and (3) solutions of known con- 

 centrations are quite easily made up. 



Salt. 



The salt was obtained as chemically pure from Merck. On 

 testing it, however, I detected free acid. This disappeared on 

 once re-crystallizing and heating to constant weight. Solutions 



* Proc. and Trans. N. S Inst. Sci.. Vol. X., p. 211, 1899-00. 

 t Phil. Trans., A, Vol. 194. 1900, pp. 321-360. 



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