26 



CONDUCTIVITY AND VISCOSITY IN MIXED SOLVENTS. 



SOLUTIONS. 



The method of making up the original mother-solutions will be given when 

 the various electrolytes are considered. From this mother-solution the 

 remaining solutions were made by successive dilutions by means of burettes 

 and measuring flasks. In the cases where this would necessitate the use of 

 small quantities of the solution, a second mother-solution was made, and 

 from this successive dilutions were prepared. 



In preparing the solutions in the mixed solvents, a sufficient quantity of 

 the solvent was made by mixing the constituents in the required proportions. 

 This was then used in the same manner as a simple solvent. In preparing 

 these mixed solvents the following method was employed : x c.c. of an alcohol 

 were diluted to 100 c.c. In the following discussion such a solution would be 

 designated as alcohol x per cent. In making mixtures of methyl alcohol 

 and ethyl alcohol, the methyl alcohol was measured and diluted with the 

 ethyl alcohol, and the concentration expressed in terms of the methyl alcohol. 



CONDUCTIVITY MEASUREMENTS. 



In all determinations of conductivity from three to five different resistances 

 were used, and the values given in the tables are the mean of these values. 



POTASSIUM IODIDE. 



The salt used in this work was recrystallized a number of times. It was 

 then carefully dried and kept in a desiccator. All the mother-solutions were 

 made by direct weighing. 



TABLE 7. Molecular conductivity of potassium iodide. 



1 The values of the conductivity at marked "D" were obtained by Jones and Douglas (Amer. Chem. 

 Journ., 26, 428), while those at 25 are taken from the work of Ostwald. 

 3 Carrara. Zelinsky and Krapiwin. 



