NEW RESULTS IN ELECTROLYSIS. 



By lily G. KOLLOCK and EDGAR F. SMITH. 



(Read October 4, 1907.) 



(Contribution from the John Harrison Laboratory of Chemistry.) 



Since it was observed that anions could readily be estimated by 

 means of the mercury cathode and rotating anode {Jr. Amer. 

 Chem. Soc, 29, 447), the thought occurred that anions might also 

 be separated by the same means. With this end in view, the follow- 

 ing study was undertaken. Potassium ferrocyanide and potassium 

 ferricyanide were the salts used in the work. It was decided to 

 conduct experiments in order to find any difference which might 

 exist in the decomposition pressures. If such conditions did exist, 

 then separations might be effected by this procedure. 



The experiments were carried out in the same apparatus and 

 following the directions given in the paper mentioned above. A 

 solution of potassium ferrocyanide, containing in 50 c.c, 0.13 16 

 gram of the salt, under a pressure of 4.5 volts and a current of 0.15 

 ampere at the beginning, falling to 0.02 ampere at the end, in one 

 hour gave the total Fe(CN)6 present. This was equal to 0.0661 

 gram. The ferricyanide solution, containing 0.1070 gram of the 

 salt, equivalent to 0.0636 gram of Fe(CN)g, was subjected to the 

 same current, giving the required amount of anion in about the 

 same period of time. 



When trying the efiPect of lower currents, for example 1.5 volt 

 and 0.07-0.02 ampere, upon potassium ferricyanide, it was observed 

 that there was no decomposition of the amalgam in the outer cell. 

 But when phenolphthalein was added to the contents of the inner 

 cell, a strong alkaline reaction was indicated. The silver anode had 

 increased 0.0467 gram after an hour's action of the current, while 

 the amount of potassium present was only 0.0156 gram instead of 

 0.0253 gram, the equivalent quantity. It was decided to repeat 



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