Van Name and Maryott — Chlo? % ination of Benzene. 161 



tials at the liquid surfaces in the calculations. Although there 

 are discrepancies between the values for the three different 

 lithium chloride solutions, due perhaps to differences in the 

 temperature at which the lithium salt was dehydrated, the 

 general result is the same in each series : — Equal volumes of 

 carbon tetrachloride and of benzene raise the anode potential 

 by almost exactly the same amount, while in proportions giving 

 like conductivities the benzene produces the greater elevation. 

 These facts give no evidence of a depolarizing action on the 

 part of the benzene. 



Table III. 



Anode Potentials on Graphite. 



Solution, approximately normal LiCl in CH 3 COOH. 



Anode Potential Difference 



volts 



Solution alone _ +1'84 



50 cc of solution + 5 CC C 6 H 6 1*86 4-0*02 



Solution alone ._ 1*85 



50 cc of solution + 5 CC CC1 4 1*87 +0*02 



Solution alone _.. 1*92 



50 cc of solution + 6 CC C fi H 6 1'95 +0'03 



A like set of measurements with Acheson graphite elec- 

 trodes, recorded in Table III, gave a similar result, though the 

 effects produced were smaller. The absorptive power of graph- 

 ite for liquids made it necessary to employ new electrodes for 

 each comparison, but the same lithium chloride solution was 

 used throughout. The variations in the anode potential in the 

 pure solution were largely due to accidental differences in the 

 surface area of different electrodes. 



Other Carbon Compounds as Depolarizers. 



For comparison with the above results similar experiments 

 were made with a few other substances, including phenol, 

 acetone, ether, and several whose behavior might have a direct 

 bearing upon the problem in hand. These experiments are 

 recorded in Table IY. The platinum electrodes used were 

 those described on page 159. 



Phenol produced a marked depression of the anode potential 

 indicating a strong depolarizing action. During the measure- 

 ment the potential rose rapidly owing to the formation of a 

 thin coating of the reaction products on the anode. When the 

 film was removed and the anode replaced, the initial reading 

 was again obtained but rose rapidly as before. After the 

 electrolysis dilution of the liquid with water gave a precipitate, 



