160 Van Name and Maryott — Chlorination of Benzene. 



effect more than counteracts any tendency which the benzene 

 may possess to lower the anode potential by virtue of its 

 depolarizing power. 



A much better test can, however, be obtained by comparing 

 the effect of benzene with that of carbon tetrachloride, a 

 liquid of similar properties, having nearly the same dielectric 

 constant and a viscosity only about 50 per cent greater, but 

 one which, for chemical reasons, would be incapable of acting 

 as a depolarizer for chlorine. The ideal basis for comparison 

 would require that such amounts of the two liquids should be 

 used as would give the same concentration of chlorine ions. 

 In the absence of the data necessary for this adjustment of the 

 proportions, we have employed two different approximations, 

 and have compared the effect on the anode potential of (a), 

 equal volumes of the two liquids, and also (b), that of volumes 

 which cause like changes in the conductivity. At the dilution 

 employed the effect of 5 CC of carbon tetrachloride upon the 

 conductivity was found to be equivalent to that of nearly 6 CC 

 of benzene. 



Table II. 



Anode Potentials on Platinum. 



Conductivity Anode Potential 



at 25° ' volts 



t A ^ 



ohm- 1 '025 amp. "050 amp. 

 Solution A. 



(1-06 n LiCl in CH 3 COOH)_ .___ -00259 + 1-87 



50- cc sol. A, 5 CC C 6 H 6 -00194 1-91 



50 cc sol. A, 5 CC CC1 4 ... -00180 1-91 



50 cc sol. A, 6 ec C 6 H 6 _ -001Y9 1-93 



Solution B. 



(119 n LiCl inCH 3 COOH) -00284 +1-66 +1*73 



50 cc sol. B, 5 CC C 6 H 6 -00218 1-74 1*80 



50 cc sol. B, 5 CC CC1 4 -00194 1*75 1*79 



50 cc sol. B, 6 CC C 6 H 6 ._ _. -00204 1*89 1'95 



Solution C. 



(approx. n LiCl in CH 3 COOH)__ -00242 1*66 1*76 



50 cc sol. C, 5 ec C 6 H fi -00178 1*71 1*83 



50 cc sol. C, 5 CC CC1 4 _.. -00170 1-71 1*82 



50 cc sol. C, 6 CC C 6 H 6 ._ -00170 I'll 1*84 



Table II shows the results of these measurements. The 

 anode potentials were fairly constant and generally reproducible 

 within five millivolts. The values given have been referred 

 to the calomel electrode as -f # 56 volt, neglecting the poten- 



