C. A. Peters — Electrolysis of Sodium Chloride. 365 



Art. XL. — The Electrolysis of Sodium Chloride with the 

 Mercury Cathode ; by Chakles A. Peters. 



[Contributions from the Kent Chemical Laboratory of Yale Univ. — coxxvi.] 



Contents : 



Page. 



Apparatus - 366 



Cell ; plated anode ; silver anode ; electric apparatus ; air bath ; 

 beating crucible ; electric furnace ; mercury still ; thermometers. 



Chemicals . 368 



Sodium chloride ; hydrochloric acid ; mercury. 



Procedure - 368 



Plating anode ; electrolysis ; determination of silver in mercury. 



Depth of mercury in cell 370 



Experience with anode 370 



Drying and heating ; Table I ; increase in weight upon heating ; 

 decrease of weight upon heating ; Table II ; weighing silver chlo- 

 ride ; change of color and fusion of silver chloride ; cleaning with 

 potassium cyanide ; cleaning with ammonia ; reduction with 

 hydrogen. 



Liquid of the inner cell . . 377 



Alkalinity; Table IV ; silver oxide ; turbidity; reactions. 



Transfer of silver to cathode 380 



With silver plated anode ; Table V ; using a silver anode. 



Conditions of analysis 383 



Procedure ; results ; Table VI. 

 Summary 385 



Wolcott Gibbs* was the first to suggest the use of mercury 

 as a cathode in analysis. The extension and development of 

 this idea has been carried on by Vortmann,f Speketer,^ and 

 others,§ notably by E. F. Smith | and his co-workers. 



The present paper is concerned with the study of the elec- 

 trolysis of sodium chloride using a silver or silver plated anode 

 to hold the chlorine and a mercury cathode to fix the sodium. 

 In general, to sum up the work briefly, it may be said, that, 

 within the writer's experience, silver is invariably carried 

 from the anode to cathode, though under certain conditions 

 the amount is analytically negligible ; that the fixation of con- 

 ditions necessary for accurate analysis is dependent upon 

 many factors, such as amount of salt electrolyzed, time of 

 electrolysis, etc.; and further, that the ammeter does not 

 show by any sudden drop the correct end-point of the process. 



* Paper read before National Academy of Sciences, 1883. 



+ Monatshefte f. Chemie, xv, 280, 1894 ; xvi, 674, 1895. 



X Zeitschr. f. Electrochem., iv, 539. 



i?See references in Gooch and Eead, this Journal, xxviii, 544, 1909. 



I Electro- Analysis, 1907. 



