128 G. J. BURROWS. 



degree of dissociation of the free hydrochloric acid and it 

 also has a direct effect on the rate of inversion of the 

 sucrose. To correct for this, Walker and Wood determined 

 the effect on the rate of inversion caused by the addition 

 of an amount of sodium chloride equal to that of the 

 unhydrolysed urea hydrochloride, and assumed that this 

 gave approximately the effect of the unhydrolysed salt on 

 the reaction. In a similar manner the present author has 

 determined the rate of inversion by N/2 (HOI + NaOl) in 

 alcoholic solutions. Thus, a solution in 50 per cent, alcohol 

 which was seminormal with regard to the total chlorine, 

 but contained 57*9 per cent, of this as hydrochloric acid 

 and 42*1 per cent, as sodium chloride, was found to give a 

 mean rate of inversion of sucrose k = '00092. As the 

 corresponding value for the inversion by N/2 hydrochloric 



acid and M/2 urea was '00103 the correct degree of hydro- 



103 

 lysis is considered to be '579 x — — . The correcting 



factor was determined in a similar way for each of the 

 other solutions. 



In Table III are given the values for the degree of hydro- 

 lysis (h) corrected in this way. 



Table III. 

 M/2 urea hydrochloride. Temperature 25 0° C. 



Alcohol % (^ 



'Ol.) 



n 2 

 fa 



factor 



h 









•653 



1-059 



•691 



40 





•583 



1-100 



•647 



50 





•579 



1-120 



•648 [-630] 



GO 





•543 



1-110 



•603 



70 





•515 



1-107 



•570 



The degree of hydrolysis is seen to decrease with decreas- 

 ing concentration of water. The value for 50 per cent, 

 alcohol is obviously too high. The value for this solution, 

 obtained by plotting a curve for the other mixtures, is h = 



