126 G. J. BURROWS. 



water-alcohol mixtures. 1 The investigation has since been 

 extended, the degree of hydrolysis of urea hydrochloride of 

 different concentrations having been determined in mixtures 

 of water and ethyl alcohol and water and acetone. 



I. Ethyl alcohol-water Mixtures. 



The method employed for determining the degree of 

 hydrolysis of the hydrochloride was similar to that described 

 by Walker (loc. cit.) for aqueous solutions, and is as follows. 

 The rate of inversion of sucrose solution by hydrochloric 

 acid was determined, and then the rate of inversion by 

 hydrochloric acid containing the required amount of urea. 

 By assuming that the rate of inversion of the sucrose is 

 proportional to the concentration of free acid (for any par- 

 ticular solvent), the degree of hydrolysis of the salt is 

 expressed as the ratio of the inversion velocity in the solu- 

 tion containing urea to that in the solution containing no 

 urea. The method adopted in preparing the solutions and in 

 following the course of the reaction was the same as that 

 described in a previous paper on sucrose inversion. 2 All 

 alcohol or acetone percentages given in this paper are by 

 volume. 



The rate of inversion was calculated from the usual 

 equation 



Where Ro is the initial rotation 



i^is the rotation after complete inversion 



Rt is the rotation after an interval of t minutes. 



The agreement between the values of k obtained in any 

 experiment was quite satisfactory. The following table 

 contains the result of an experiment with 70 per cent, 

 alcohol as the solvent and is quoted as an example. 



1 Burrows and Fawsitt, J.C.S., 1914, 105, 612. 

 2 J.C.S., 1914, 105, 1260. 



