﻿Calcium Carbonate in Water. 



Conductivity o£ NaHCO s . 

 v = 10*07 (vol a metrically) ; 10*08 (gravimetrically), 



975 





With pure Water. 





V. 



. 





With Water 

 containing C0 2 . 









Uncorrected. 



Corrected. 





1007 



76-3 



763 



76-5 



20-15 



80-8 



80-8 



81-0 



40-3 



84-6 



84-6 



81-8 



80-6 



87-4 



87-4 



87-8 



161-2 



80-8 



89-7 



90-1 



322-4 



917 



91-6 



92-1 



645 



93-4 



93-1 



94-2 



1290 



94-6 



94-1 



98-3 



2580 



95-9 



949 



107-5 



5160 



98-2 



(96-1) 



137-3 



10320 



101-7 



(97-6 ) 



— 



00 



— 



97-0 



1 



It will be seen that the two series are practically identical 

 up to the limits investigated by Walker and Cormack. At the 

 higher dilutions, however, the presence of the excess of car- 

 bonic acid in the solution gives rise to a rapidly-increasing con- 

 ductivity value. This is due to the ionization of the carbonic 

 acid, which is quite appreciable in the more dilute solutions. 



The corrected values for the first series lead to a conduc- 

 tivity value at infinite dilution of 97'0. At the two highest 

 dilutions hydrolysis has evidently begun to be appreciable. 

 The velocity of the HCOg' ion is therefore found to be, taking 

 the velocity of the sodium ion as 51*0, equal to 46*0. 



Calcium bicarbonate solution was made up as previously 

 described, the requisite volume of lime-water of known con- 

 centration being run into water containing carbon dioxide to 

 give a solution of dilution 32. This was too unstable at 25° C. 

 to permit of a conductivity value being obtained before precipi- 

 tation of carbonate occurred. A series was obtained, however, 

 from dilutions 50 to 8000 ; results are given below. The 

 dilutions were with pure water, of conductivity 1*10 x 10~ 6 . 



Conductivity. iCa(HC0 3 ) 2 . 



y. 



Uncorrected. 



Corrected. 



50 



81-0 



81-0 



64 



83-5 



83-5 



128 



88-9 



S8-9 



256 



93-4 



93-3 



512 



96-8 



96-6 



1024 



100-0 



99-6 



2048 



103-0 



102-2 



4096 



106-7 



(105-1) 



8192 



1120 



(108-7) 



CO 



— 



1080 



