s 



The Philippine Journal of Science 



1913 



For our experiments, a sample of ligroine free from benzene 

 hydrocarbons was used. For determining the partition coeffi- 

 cient, 500 cubic centimeters of pure water were shaken at 30° 

 with 25 cubic centimeters of ligroine in which a weighed amount 

 of ester was dissolved. After two hours' shaking, the water 

 was siphoned off and colorimetric determinations were made of 

 the methyl salicylate in 10 cubic centimeters of each layer. 



Experiment No. 



Ester 

 per cc. of 

 ligToine. 



Ester 



per cc. of 



water. 



Partition 

 coefficient. 



1 . 



0. 08962 

 0.06300 

 0. 07977 



0.00064 

 0.00048 

 0.00060 



140.0 

 131.2 

 132.8 



2 . _ 



3 





134.7 





Therefore, the concentration of methyl salicylate in the ligroine 

 will be about 135 times that in the water under the conditions 

 stated. 



In order to determine the hydrolytic constant of sodium methyl 

 salicylate, experiments were carried out under the same con- 

 dition as above, except that pure dilute aqueous sodium hydroxide 

 of known titre was substituted for the water, a, i, and x were 

 determined by the methods given above; e was taken as 1/135 

 times the concentration of methyl salicylate in the superincum- 

 bent ligroine layer. The data obtained follow, r was calculated 

 from equation (6). 



No. 2. 

 0.0638 

 0.0155 

 0.0600 

 0.0059 

 0.00124 



Experiments by the method of maximum solubility were 

 carried out as follows. About 5 grams (a large excess) of 

 methyl salicylate were shaken for about two hours at 30° with 

 about 25 cubic centimeters of standard sodium hydroxide with 

 the following results: 



No. 2. 



0.0993 



0.0481 



0.0971 



0.005 



0.00070 





No. 1. 



a = 



0.0159 



x = 



0.0072 



i = 



0.0114 



e = 



0.0005 



r = 



0.00066 





No. 1. 



a = 



0.0993 



x = 



0.0483 



i = 



0.0970 



e = 



0.005 



r = 



0.00072 



