516 



Conductivity of Mixtures of Electrolytes. 



Constituent Solutions 



(gramme-molecules per 



litre). 



Conductivity of Mixture 



xio 8 . 



Difference 

 per cent. 



HC1. 



NaCl. 



Calculated. 



Measured. 



2 



2-5 

 3-0 

 3-5 



4-0 

 4-5 



2-02 

 >> 



55 

 55 



3020 



3489-5 



3885 



4233-5 



4622-3 



4944 



3008 

 3456 



3888 

 4260 

 4580 

 4880 



+ 0-4 

 + 1-0 

 -008 

 -0-6 

 + 1-0 

 +1-3 



1 



1-5 



20 



2-5 

 30 

 3-5 

 4-0 

 4-5 



1-04 



)> 



55 

 55 

 5» 

 55 

 55 

 55 



1751 

 2373 



2928-3 



3428-5 



3906 



4340-7 



4715 



5055 



1752 

 2332 

 2900 

 3398 

 3872 

 4316 

 4700 

 5036 



-0-005 



+1-7 



+0-9 



+0-9 



4-0-9 



+0-6 



+0-3 



4-0-4 



•4 



•5 



•6 



•7 



•8 



•9 



1-0 



1-1 



1-2 



•607 



55 



55 

 55 



55 

 55 



829-8 

 983-4 

 1125-5 

 1255 

 1384-7 

 1524-6 

 1658-9 

 1787-6 

 19171 



838 

 976 

 1116 

 1250 

 1388 

 1525 

 1656 

 1784 

 1913 



-1-0 



4-0-8 



4-0-8 



+0-4 



-02 



-0-025 



4-016 



4-0-2 



4-0-2 



It will be seen that in the series of weakest solutions, the 

 differences between calculated and observed values are of 

 such small magnitude and show such alternation of sign as 

 to warrant the conclusion that they are due chiefly to acci- 

 dental errors. In the two series of stronger solutions the 

 differences are more irregular in magnitude and the alterna- 

 tion of sign is much less marked, the most of the differences 

 being positive. The above results, therefore, seem to show 

 that even in the case of two electrolytes, with a common ion 

 which differ so markedly in ionic velocity from one another 

 as sodium chloride and hydrochloric acid, the dissociation 

 theory enables us to calculate the conductivity of solutions 

 containing both, within the limits of experimental error, up 

 to a mean concentration of about one gramme-molecule per 

 litre, and that in the case of solutions of greater mean con- 

 centration the calculated value is greater than the observed. 



