KINETICS OF CERTAIN SILVER SALTS 281 



TABLE I 



57-81 65-80 



It will be seen that the strength of two middle portions has 

 remained constant, within the errors of determination; we 

 also find a close agreement in the second test, which demands 

 that the mean concentration shall remain unchanged; the 

 value 65.80/57.81 = 1.138, scarcely different from the original 

 strength 1.139. 



The measurement of the electrical current as described 

 above informed us that a quantity of electricity equivalent 

 to the precipitation of 32.10 mg. of silver had passed through 

 the apparatus; while a silver- voltameter, placed in the circuit 

 for our better assurance, contained 32.2 mg.; the former value 

 was accepted as the more trustworthy. 



Following Hittorf, 1 we based these calculations upon our 

 data: The solution at the anode (1) received from the latter 

 32.1 mg. Ag, and the uppermost layer (4) gave up the same 

 amount to the cathode. Owing to the changes in concentra- 

 tion, the values in the above table are not absolutely correct, 

 since 1 gram of solution does not always contain the same 

 weight of water, as had been provisionally assumed. But the 

 necessary correction is small and readily made. Let v be 

 the ratio of the molecular weights of silver and the salt in 

 question; in this special case v = ^ = 1.57. Let a represent 

 the amount of silver contained in 1 gram of [113] unaltered 

 solution, being consequently dissolved in (Iav) grams of 

 water. If, after electrolysis, q grams of the solution about 

 one electrode are found to contain b grams of silver, the 



1 Hittorf, Pogg. Annalen, 98, 19. 



