HYDROLYSIS OF UREA HYDROCHLORIDE. 129 



•630; this value will be used in the subsequent discussion. 

 Experiments were also performed with solutions containing 

 N/2 hydrochloric acid and M/2 urea at 30° C. It was found 

 that at this temperature the value for h in water was the 

 same as at 25° O., while the value in 70 per cent, alcohol 

 was decreased by about 3 per cent. Prom the figures in 

 Table III it is possible to calculate the hydrolysis constant 

 for urea hydrochloride in each of these mixtures. If we 

 represent the degree of hydrolysis by h, and the volume in 

 litres which contains 1 gram molecule of urea hydrochloride 

 by v, (which in this case equals 2) then the hydrolysis 

 constant H is given by 



(l-h)v 

 The values of H are given in Table IV. 

 Table IV. 



Alcohol % (vol.) h H 







40 

 50 



60 

 70 



The value of H in water 

 by Walker and Wood (*781) 



691 -773 



647 -593 



630 -536 



603 -458 



570 -378 



is a little lower than that given 

 This is due to the small differ- 

 ence between the values of h found by them and the present 

 author. 



The degree of hydrolysis of M/10 urea hydrochloride was 

 determined at 40° O. These results are given under Jii in 

 Table V, together with the values calculated from H under 

 h (calc). In determining li\ no correction has been applied 

 to the ratio— 2 as it has been considered unnecessary owing 

 to the small effect of the unhydrolysed salt at this com- 

 paratively high dilution. The values under h (calc) are 



I— October 1, 1919. 



