144 Conductivities and Viscosities in Pure and in Mixed Solvents. 



be seen from the results obtained a year ago by Wightman, Wiesel, and 

 Jones. 1 For example, the conductivities of o-chlorbenzoic acid and of 

 o-nitrobenzoic acid are approximately the same as that of benzoic, but 

 the conductivities of the corresponding para-acids are considerably less. 



It is well established that in aqueous solution the conductivity of 

 benzoic acid is somewhat increased by the introduction of methyl, 

 chlorine, or the nitro group, in the para position, and enormously 

 increased by the introduction of one of these groups in the ortho posi- 

 tion. In contradistinction to this, the effect of these groups upon the 

 conductivity in alcoholic solution appears to be negative. Just the 

 opposite is true if the chlorine or nitro group occupies the meta position, 

 as can be seen from the data. In these cases the conductivity of ben- 

 zoic acid is somewhat increased. 



The introduction of a second nitro group into w-nitrobenzoic acid 

 still further increases the conductivity. While benzoic acid, C 6 H 5 COOH, 



/COOH 



has a conductivity of only 0.015, phthalic acid, C 6 H 4 \ a 



X COOH( ) 



dicarboxy derivative, has a conductivity of 0.108, which is seven times 

 as great. This same relation holds in aqueous solutions. 2 



Of all the acids studied in this investigation with one exception, 

 picric acid, C 6 H 2 (N0 2 )30H, is the strongest. The only stronger acid in 

 alcoholic solutions is sulphosalicylic, which has a conductivity ap- 

 proaching that of hydrochloric acid in this solvent. This is in general 

 analogous to what was found when these compounds were dissolved in 

 water, 3 sulphosalicylic acid in water having almost exactly the same 

 conductivity as hydrochloric acid in that solvent. 



In order to compare the conductivities of the above-named organic 

 acids in alcohol with the conductivities of these same compounds in 

 water, reference must be had to publication of the Carnegie Institution 

 of Washington No. 170. 



Mourn. Amer. Chem. Soc., 36, 2251-2252 (1914). 3 Ibid., 120, 121. 



2 Carnegie Inst. Wash. Pub. No. 170, 116, 133 (1912). 



