viii, a, i Gibbs, Williams, Galajikian: Methyl Salicylate IV 



11 



In order to test the correctness of the value for K as found in 

 Table I, the rate of saponification was determined in homo- 

 geneous aqueous solution by using a concentration not exceeding 

 the maximum solubility of the ester. The values for K in this 

 case were calculated according to the equation for a reaction of 



1 x 



the second order K = 

 Table II. 



f a (a— x) 



The results are found in 



Table II. — Saponification of methyl benzoate with NaOH. 

 NaOH = 0.014.7. Ester = 0.0147. T = 30° ±0.1°. Indicator corallin. 



t. 



X. 



a — x. 



t a (a— x) 



o 







0. 0147 





5 



0.0044 



0.0103 



5.784 



10 



0.0066 



0. 0081 



5.516 



16 



0. 0082 



0.0065 



5.345 



26 



0.0098 



0. 0049 



5.232 



36 



0. 0107 



0.0040 



5.055 



46 



0.0116 



0.0031 



5.534 







5.411 









The values for K obtained by the two methods agree fairly 

 well in magnitude, considering that the small concentrations 

 used, when working in homogeneous solution, greatly magnified 

 the experimental error. 



THE SAPONIFICATION OP THE METHYL ETHER OF METHYL SALICYLATE 



The methyl ether of methyl salicylate was also investigated 

 in the same manner to test the validity of calculating the reaction 

 velocity constant in nonhomogeneous solution according to a 

 reaction of the first order. The solubility of the methyl ether 

 of methyl salicylate in water at 30° was first determined by the 

 same method as was used for methyl benzoate. The results are : 



Experiment No. 



N/10 NaOH 



required for 25 



cc. saturated 



solution of 



ester. 



Molar 

 solubility. 



1 



9.20 

 9.32 

 9.30 



0.0368 

 0. 0373 

 0.0372 



2 



3. 









0. 0371 





