138 CONDUCTIVITY OF AQUEOUS SOLUTIONS. BARNES. 



in all the calculated values of the conductivity. There is also (2) 

 the possibility referred to abore, of the sulphuric acid breaking 

 up not only into ions of 2 H and SO 4 , but also into H and 

 HSO 4 . 



It is also possible by plotting the above series to obtain series 

 of mixtures having a constant concentration for the constituent 

 hydrochloric acid solutions and variable concentrations for the 

 sulphuric acid constituent solutions ; and it will be found in 

 series of this kind that the same regular progression is exhibited 

 as in the above. It may be well to note that in the last three 

 series of the above Table where the sign of the difference 

 changes, this change happens for all when the average concen- 

 tration of the mixture is about 0.6 gramme-equivalents. 



Finally, since my experiments are estimated as affected by 

 an error which may amount to about 0.3 per cent., it is seen 

 in the table that as the differences for the three last series are all 

 within or in a few cases but little beyond this error, it may be 

 concluded that the conductivity of mixtures of dilute solutions 

 of hydrochloric and sulphuric acid can be calculated within the 

 limit of my experimental error, by the expression of the dissocia- 

 tion theory and on the assumption that the sulphuric acid dis- 

 sociates into 2 H and SO 4 as ions, up to an average concentration 

 of about 0.5 in cases in which the concentration with respect to 

 sulphuric acid is relatively large, and up to an average concen- 

 tration of about 0.9 in cases in which the concentration with 

 respect to this acid is relatively small. 



