J. H. Reedy — Anodic Potentials of Silver, 



411 



Table III. Separation of the Halogens. 



(Volume of Solution = 210 cc .) 



Iodine from Chlorine. 



Number 



Chlorine 



Maximum 



Iodine 



Iodine 





of 



cono. 



anode pot. 



taken 



found 



Error 



Exp. 



moles 



volts 



grams 



grams 



grama 



17 



•0046 



•190 



•0620 



•0617 



— •0003 



18 



•0046 



•190 



•0620 



•0619 



— •0001 



19 



•0046 



•190 



•0620 



•0619 



— •0001 



20 



■0046 



•190 



•0620 



•06)8 



— •0002 



21 



•0046 



•190 



•0620 



•0621 



+ •0001 







Iodine from Bromine. 







Number 



Bromine 



Maximum 



Iodine 



Iodine 





of 



cone. 



anode pot. 



taken 



found 



Error 



Exp. 



moles 



volts 



grams 



grms 



grams 



22 



•0046 



•190 



•0620 



•0623 



+ •0003 



23 



•0046 



■213 



•0620 



•0628 



+ •0008 



24 



•0046 



•190 



•0620 



•0621 



+ •0001 



25 



•0046 



•190 



•0620 



•0620 



0000 



26 



•0046 



•190 

 Bromine fr 



•0620 

 om Chlorine. 



•0619 



— •0001 



Number 



Chlorine 



Maximum 



Bromine 



Bromine 





of 



cone. 



anode pot. 



taken 



found 



Error 



Exp. 



moles 



volts 



grams 



grams 



grams 



27 



•0010 



•400 



•0396 



•0401 



+ •0005 



28 



•0010 



■400 



•0396 



•0389 



— •0007 



29 



•0010 



•400 



•0396 



•0394 



— •0002 



30 



•0010 



•400 



•0396 



•0395 



— •0001 



31 



•0010 



•400 



•0396 



•0393 



— •0003 



32 



•0024 



•400 



•0396 



•0469 



+ •0073 



separation. Consequently, some chlorine was deposited along 

 with bromine in the later stages of the electrolysis. It is inter- 

 esting to note that the positive error of '0073 grams agrees 

 closely with the error that might be expected from theoretical 

 considerations. The excess of the chlorine concentration 

 over - 0014: molar, the limit found above, was "001 molar. This, 

 for 210 cc , the volume of the solution in this experiment, is 

 equivalent to '0075 grams, which is practically identical with 

 the experimental error. 



These results confirm in a forceful way the conclusions 

 drawn above as to the effects of concentration in the electrolytic 

 separation of the halogens. 



Analytical Applications. — The processes just described are 

 not offered as analytical methods. If has been the purpose of 

 the writer throughout this investigation merely to determine 



