II. ON A TEST, BY THE FREEZING-POINT METHOD, OF THE 

 IONIZATION COEFFICIENTS DETERMINED BY THE CONDUC- 

 TIVITY METHOD, FOR SOLUTIONS CONTAINING POTASSIUM 

 AND SODIUM SULPHATES. BY E. H. ARCHIBALD, M. Sc., 

 1851 Exhibition Science Scholar, Dalhousie College, 

 Halifax, N. S. 



(Communicated by Prof. J. G. MacGregor; Received September 15th, 1898.) 



The experiments described below were undertaken, at e 

 suggestion of Prof. J. G. MacGregor, for the purpose of testing 

 the values of the ionization coefficients obtained by means of his 

 graphical method,* in the case of a mixture of solutions of two 

 electrolytes with a common ion, by employing them in the calcu- 

 lation of the depression of the freezing-point, and comparing the 

 calculated values with values obtained by experiment. 



The time at my disposal was very limited, and in consequence 

 I was able to make the test only in the case of equimolecular 

 solutions of two electrolytes. Potassium and sodium sulphates 

 were selected as the electrolytes, not because of their being the 

 most suitable for the purpose, but because I had been observing 

 their conductivity and had already obtained some of the requisite 

 data. 



As, in determining the depression of the freezing-point, the 

 solutions must be at a temperature of about C., it was neces- 

 sary that the ionization coefficients should be determined for 

 approximate!}' the same temperature. Both the specific con- 

 ductivities of simple solutions of the two electrolytes throughout 

 the range of concentration of the simple solutions used in 

 preparing the mixtures, and their equivalent conductivities at 

 infinite dilution, had therefore to be determined for C.,as well 

 as the depression or the freezing-point for the mixtures. In 



*Trans. N. S. Inst. Sci., 9, 101, (1895-6). 



PROC. & TRANS. N. S. INST. Sci., VOL. X. TRANS. C. 



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