388 On Hydrolysis in Aqueous Salt-Solutions. 



The next small table contains the collected results of these 

 experiments. 



Cone. Ester. 



K. 



A. 



KCN hydrolysed. 



0-4870 

 0-2005 

 0-1013 



0-00131 

 000151 

 0-00148 



0-00114 

 0-00124 

 0-00124 



1-13 per cent. 

 1-20 „ 

 1-18 „ 



The numbers show that the concentration of the ester has 

 no measurable influence on the amount of hydrolysis, since 

 the figures in the last column do not arrange themselves in a 

 series which is either gradually ascending or descending. 



The differences between them are probably chiefly due to 

 experimental error. The mean value is 1*17, and the greatest 

 deviation from it is less than 5 per cent. 



Resume. — The general results of this investigation may 

 briefly be stated as follows : — 



1st. It is shown how the velocity with which salt- solutions 

 saponify ethyl acetate may be utilized to determine the extent 

 to which hydrolysis has taken place in aqueous solutions of 

 salts of strong bases with weak acids. 



2nd. The amount of hydrolysis has been measured in solu- 

 tions of the following salts ; and in -^ molecular normal 

 solutions between 24°-25° 0. the amount of salt which is 

 decomposed by the water is 



Potassium cyanide 

 Sodium carbonate 

 Potassium phenate 

 Borax (about) 

 Sodium acetate 



1*12 per cent. 

 3-17 „ 

 3-05 „ 

 0-5 „ 

 0-008 „ 



3rd. When the salts are not hydrolysed to a great extent 

 the amount of free alkali in the solutions is nearly propor- 

 tional to the square root of the concentration. 



4th. Trisodium phosphate can scarcely be said to exist in 

 a ^q molecular normal solution, as it is almost completely 

 hydrolysed in the sense of the equation 



Na 8 P0 4 + HOH = Xa 2 HP0 4 4- NaOH. 



5th. The presence of small quantities of ethyl acetate in the 

 solution does not materially disturb the equilibrium, 



KCN+HOH 



University College, London. 



KOH + HCN 



