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



27 



The results are recorded in Table XII. t is the time in min- 

 utes; x is the amount of methyl salicylate, expressed as molar 

 concentration, hydrolyzed in time t; K H is the reaction velocity 



constant calculated from the formula K H =— . The value for 

 e is taken as 0.0117. 



Table XII.— -The hydrolysis of methyl salicylate at 100'. 



1 



2 



3 



4 



t . 



60' 



Salicylic 

 acid in 100 

 cubic centi- 

 meters. 



X. 



K H=| 



1 



0. 00255 



0. 000185 



2. 7 ■ 10-4 



2 



0. 00637 



0. 000462 



3. 3 • 10-4 



5 



0. 02146 



0. 001555 



4. 4 • 10-4 



7 



0. 02416 



0. 001751 



3. 5 • 10-4 



24 



0. 11716 



0. 008492 



5. • 10-4 



30 



0.12264 



0. 008884 



4.2-10-4 



48 



0. 19320 



0.01400 



4.2-10-4 



72 



0. 21470 



0. 01556 



3. 9 ■ 10-4 



96 



0.25760 



0. 01867 



2.8-10-4 



120 



0. 32200 



0. 02333 



2. 8 • 10-4 



168 



0. 38640 



0.02800 



2. 7 • 10-4 



3. 6 • 10-4 







It is to be noted that about one thousand times the quantity 

 of methyl salicylate is hydrolyzed in a given time at 100° as 

 at 30°, an extremely high temperature coefficient. 



The hydrolysis in N/10 solutions of sulphuric acid measured 

 in the same manner in one experiment showed that the rate 

 was considerably more rapid. Since the measurements have 

 not been repeated, we are not justified in making any further 

 statements. 



Attempts were made to follow the rate of hydrolysis at 100° 

 in sealed tubes fitted with electrodes by means of conductivity 

 measurements, but the glass employed was so readily attacked 

 that the measurements were of no significance. While the 

 results are not satisfactory for the purposes in view, they may 

 be of some interest and are briefly described as follows: 



Sealed tubes containing equal quantities of methyl salicylate 

 and conductivity water were agitated in a steam bath at 100° 

 from October 7, 1908, to December 2, 1908— a period of fifty- 

 six days — and the contents roughly estimated. Determinations 

 are calculated to 100 cubic centimeters of solution. 



