OF CERTAIN ORGANIC ACIDS IN AQUEOUS SOLUTIONS. 59 



in the work of Springer 1 the maximum dissociation was reached in 

 every case studied by him, except for the amino acids, such as sulpha- 

 nilic, metanilic, naphthionic, and dinitroaminophenol. Smith did not 

 studjr acids of this class; but certain groups of those which he has 

 investigated show an increase in dissociation over a wide range in 

 temperature. The acids that show this property to the greatest extent 

 are those containing the hydroxyl (OH) group. These acids have per- 

 centage dissociation values which increase, attain a maximum, and 

 then decrease. 



TABLE 18. Dissociation constants. 



*Value found by some other investigator; see Publication of the Carnegie Institution 



of Washington, No. 170. 



The temperature coefficients of conductivity expressed in conduc- 

 tivity units, for all of the above acids show an increase with the dilution 

 of the solution and a decrease with rise in temperature. As would be 

 expected, the rate of increase or decrease varies greatly. There seems 

 to be a relation between the strength of the acid and rate of increase 

 or decrease of the temperature coefficients of conductivity with rise in 

 temperature. The stronger the acid the less rapid is the change. 

 It should be noted that strong acids are so largely dissociated at all 



. Chem. Journ., 48, 411, (1912). 



