130 G. J. BURROWS. 



calculated from the corresponding values of H (at 25° 0.) 

 by substituting in the equation 



TT Oa X C B 



Cab 



where A = the concentration of free hydrochloric acid 

 B = the concentration of free urea 

 AB = the concentration of unhydrolysed salt 



Table V. 



l%(vol.) 

 



•00265 



k 2 

 ■00241 



•906 



h (calc.) 

 •897 



25 



•00255 



•00219 



•859 



•882 



50 



•00230 



•00196 



•852 



•860 



75 



•00274 



•00219 



•800 



•805 



%(vol.) 

 



h 



•00219 



25 



•00204 



75 



•00208 



809 



h (calc.) 

 •826 



793 



•811 



729 



•737 



Experiments with 10 per cent, sucrose and N/2 hydro- 

 chloric acid and M/4 urea at 25° O. gave the following 

 results. 



Table VI. 



k 2 factor 



-00172 1-03 

 •00154 1-05 

 •00143 1-06 



The agreement between the calculated and experimental 

 results justifies the conclusion that in water-alcohol mix- 

 tures the effect of dilution may be expressed by the ordinary 

 dilution law. That is, the amount of salt hydrolysed 

 depends on the concentration of the salt expressed in terms 

 of the total volume — it is not simply proportional to the 

 amount of water in the solution. 



II. Acetone-water Mixtures. 



Similar experiments were carried out with acetone- water 



mixtures as solvents. In this case the concentration of 



free acid was determined by its effect in hydrolysing methyl 



acetate. In determining the degree of hydrolysis of the 



