318 Conductivity of Aqueous Solutions. Part XL 



hydrochloric acid used (No. 2) had a conductance of 21372 and the por- 

 tions withdrawn at the end of the experiment had conductances as 

 follows : K* 21336 ; M K , 21355 ; M, 21349 ; Ma, 21349 ; A, 21356. There 

 was on an average a decrease of 0.1 per cent. Although this would 

 cause a not inconsiderable divergence of the cathode and anode trans- 

 ference numbers, yet it would not affect their mean appreciably ; therefore 

 no correction was made for it (except that the use of 21360 as the initial 

 value eliminated it in great measure in the experiments with this solution.) 



114. THE EXPERIMENTAL DATA. 



The data of the experiments and the calculated transference values for 

 the 0.06 0.007 normal nitric acid solutions are given in tables 132 - 134. 

 The first column contains the number of the experiment; the second, the 

 number of the acid solution used ; the third, letters representing the dif- 

 ferent portions submitted to analysis, K signifying the cathode solution, 

 Mk the adjoining middle portion, M the next portion, Ma the portion 

 adjoining the anode, and A the anode portion itself; the fourth, the 

 weight in grams of the separate portions ; the fifth contains the number 

 of grams of barium hydroxide solution used in neutralizing the portions 

 after the electrolysis ; the sixth, the initial content, expressed in equiva- 

 lents and multiplied by 10 6 , as calculated from the weight of the portion 

 and the standardization value ;f the seventh, the final content calculated 

 from the barium hydroxide used ; the eighth, the change in content of 

 the separate portions; the ninth, the total change in content, which 

 includes the changes in the portions adjoining the cathode and anode ;% 

 the tenth, the milligrams of silver precipitated in the coulometers; and 

 the eleventh, the calculated transference numbers for the anion multiplied 

 by 1000. 



*For the meaning of these letters see the next paragraph. 



fSee section 113, BaC^H;. Solution No. 1 was used in experiments 1 to 6; Solu- 

 tion No. 2 in experiments 7 to 26 ; and Solution No. 3 in experiments 27 to 32. 



JExcept where the change in the adjoining portion was opposite in sign to that 

 in the electrode portion. 



The way in which these were calculated may be illustrated with the help of the 

 data obtained in the first experiment. The cathode portion submitted to analysis 

 weighed 214.08 grams and was found to require 107.72 gm. of the Ba0 2 H 2 solution 

 containing 0.11064 milli-equivalents per gram, so that the final content of the portion 

 was the product of these last two quantities or 11.918 milli-equivalents. To deter- 

 mine the original content the weight of the portion is multiplied by the original con- 

 centration of the solution (0.05922 milli-equiv. per gm.), which gives 12.678 milli- 

 equivalents. The decrease in content in the cathode portion is, therefore, 0.760 

 milli-equivalents. Adding to this the decrease in the adjoining middle portion 

 (0.005) and dividing by the number of milli-equivalents of silver (523.0/107.93) 

 precipitated in the coulorneter, the transference number is found to be 0.1579. The 

 small correction for the change in weight of the electrode portions by the electrol- 

 ysis and transference is applied later. 



