12 



The Philippine Journal of Science 



1913 



The data for the saponification of this ester with sodium 

 hydroxide in nonhomogeneous and homogeneous solutions are 

 found in Tables III and IV, respectively. Again the two 

 methods of obtaining the reaction velocity constant give fairly 

 satisfactory agreement. 



Table III. — Saponification of methyl ether of methyl salicylate with NaOH 

 in nonhomogeneous solution. NaOH = 0.1030. Ester {excess) =0.371 

 constant. T — 30° ± 0.1. Indicator corallin. 



t. 



X. 



a — x. 



Ki =¥- 



log- 2 — • 

 a —x 



K- Kl • 



0.0371 











0. 1030 





4 



0.0270 



0. 0760 



0. 07590 



2.046 



9 



0.0514 



0. 0516 



0. 07671 



2.068 



14 



0.0690 



0.0340 



0. 07909 



2.131 



20 



0. 0814 



0. 0216 



0. 07800 



2.103 



30 



0.0921 



0. 0109 



0.07479 



2.016 



40 



0.0960 



0.0070 



0. 06716 



1.810 





Average 



2.029 



Table IV. — Saponification of the methyl ether of methyl salicylate with 

 NaOH in homogeneous solution. NaOH = 0.0308. Ester = 0.0308. 

 T = 30° ± 0.1. Indicator corallin. 



t. 



x. 



a — x. 



t _l x 



t a (a — x) 





 4.5 





0. 0308 

 0.0230 





0.0078 



2.447 



9.0 



0.0132 



0. 0176 



2.706 



15.0 



0. 0169 



0. 0139 



2.631 



25.0 



0. 0205 



0. 0103 



2.585 



35.0 



0.0228 



0.0080 



2.643 



45.0 



0.0240 



0.0068 



2.547 



55.0 



0.0252 



0.0056 



2.655 



75.0 



0.0263 

 Average 



0.0045 







2.530 



2.593 



IV. THE EFFECT OF CONTACT ACTION 



In order to determine the possible influence of contact action 

 on the saponification, the rate of change in the presence of large 

 excess of ester was compared with that in presence of small 

 excess, methyl salicylate being employed for this purpose. 



The theoretically equivalent amount of ester was shaken for 

 about two hours with 25 cubic centimeters of N/10 sodium 

 hydroxide solution, the shaking apparatus revolving at about 20 



