54 ON THE CONDUCTIVITY, SPECIFIC GRAVITY AND 



fully analysed. Seventy-five cc. of a solution was introduced 

 into the electrolytic cell, and successive dilutions prepared therein 

 by the withdrawal of a certain volume and the addition of an 

 equal volume of water at the temperature 18 C. This process 

 was continued till the dilution reached that of the next formerly 

 prepared solution, when the new one was introduced and the 

 same process repeated. After each solution had gone through 

 two dilutions the volume removed was analysed, the result 

 serving as a check upon the calculated strength of the solution 



in the cell. 



Preparation of Mixtures of Solutions. 



Simple solutions of each electrolyte were prepared and 

 analysed. These were kept in the bath till they had taken the 

 temperature 18 C , when 50 cc. of each solution was removed, 

 and the two mixed. The 50 cc. pipette used was thoroughly 

 washed with a portion of the solution before the removal. 



Results of Conductivity Observations on Simple Solutions. 



For the purpose of calculating the ionization coefficients of 

 the salts in the mixture, it is necessary to draw curves for 

 -simple solutions of each salt, showing the relation of the dilution 

 to the ionic concentration. The following tables give the data 

 for the drawing of these curves, obtained from observations on 

 the concentrations and conductivities of a number of solutions 

 of each salt. 



The dilutions are expressed in terms of litres per gramme 

 equivalent at 18 C. The atomic weights used were relative to 

 oxj^gen (16.00) and the same as employed by 1 Kohlrausch. The 

 specific conductivities are those at 18 C, expressed in terms of 

 10~* times Kohlrausch's new unit (Ohm-^m." 1 ) 



The concentrations of ions are the quotients obtained by 

 dividing the specific conductivities by the specific molecular 

 conductivities at infinite dilution. 2 Kohlrausch's values for the 

 specific molecular conductivities at infinite dilution were used, 

 namely, for potassium chloride 1312 X lO"*. and potassium sul- 

 phate, 1350 x 10-*. 



1 Kolil. u. Hoi., lot: cit., p. 205, tab. 14. 



2 Ibid., p. 200, tab. 8. 



