290 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



catalytic power of the neutral molecule. The values of the constants 

 K- and K may be determined from a series of measurements. In the 



case of the examples given above the following values of K^C^ were 



obtained for trichlorobutyric acid as catalyzer at concentrations of 0.1 

 and 0.05 N. 



TABLE CXVII. 



VELOCITY COEFFICIENTS FOR THE HYDROGEN ION OF TRICHLOROBUTYRIC 

 ACID IN THE ESTERIFICATION OF DIFFERENT AdDS. 



Con- 

 centration Phenyl- 

 of Acid acetic Acetic n-Butyric i-Butyric i-Valeric 



0.1 0.0157 0.0358 0.0167 0.0122 0.00448 



0.05 0.0109 0.0247 0.0114 0.00826 0.00304 



Ratio .... 1.44 1.45 1.47 1.48 1.47 



It is seen that the ratio of the velocity coefficients calculated for the 

 ions between 0.1 and 0.05 N is 1.46. According to conductance measure- 

 ments the ratio of the ionization of this acid at these two concentrations 

 is 1.42. Taking into account the numerous possible sources of error, the 

 agreement appears fairly satisfactory. 



K n 



In the following table are given values of K and - for hydrochloric 



K * 



acid, acetic acid, and the chloro- substitution products of this acid. 12 



TABLE CXVIII. 



T7- 



VARIATION OF THE RATIO -=^ FOR DIFFERENT ACIDS. 



K i 



Acid | * x? ** 1 



Hydrochloric acid 780 1.77 



Dichloroacetic acid 220 0.50 5.1 X 10' 2 



a-p-Dibromopropionic acid 67 0.152 1.67 X 10~ 2 



Monochloroacetic acid 24.5 0.055 0.155 X 10' 2 



Acetic acid 1.5 0.0034 0.0018 X 10' 2 



Similar results have been obtained by Taylor and by Ramstedt. 13 It is 

 clear that the value of K n increases with the strength of the acid. As 



"Dawson and Fowls, J. Ghent. Soc. 10& 2135 (1913). 



"Taylor, Meddel K. Vet.-Akad's. Nvbelinstitut, Vol. 3, No. 1 (1913) ; Ramste<Jt, ibid., 

 Vol. Jj No. 7 (1015). 



