60 Mr Chittock, The Migration Constants of 



Hence, from the equation on p. 56, we obtain 

 _qV8n 



lOOOj? 



qV dn BR ,, . 



From the numbers given by Kohlrausch, a curve was plotted, 

 with n as abscissa and k as ordinate. This curve is a straight 

 line over the range covered by these experiments, and we may take 



the value of -^ to be constant. The value of k corresponding to 



the known concentration of the solution was read off from the 

 curve, and the migration constant p calculated from the above 

 equation. 



The volume V of the separated liquid was determined as 

 follows. The cell was placed in position in the tank, and filled 

 with water up to the mark on the tube at P. It was then 

 weighed. The separation was now carried out in the usual 

 manner, the electrode on one side removed and dried, and the 

 separated water extracted, the last drops being removed with 

 filter-paper. The cell was again weighed, and the difference of 

 weight gave the weight of water separated. The whole process 

 was then repeated for the other side of the apparatus. 



The results of the experiments are given in the following 

 table. The concentration n of the solution is given in gram- 



