L )( ,H> Lin hart — Hydrolysis of Metallic Alkyl Sulphates. 



tion, due to the inclusion of either alkyl barium sulphate, alkyl 

 sulphuric acid, or possibly both. In the case of the methyl 

 salt very little charring was observed, whereas in the propyl 

 the whole mass turned black, so that the crucible had to be 

 inclined and the lid placed in such a way as to allow a current 

 of air to pass through during the ignition, until the barium 

 sulphate became white. 



Theory. — From theoretical considerations, which have been 

 confirmed by experimental results, it has been shown that for 

 every two gram equivalents of alkyl barium sulphate decom- 

 posed or of barium sulphate formed, one gram equivalent of 

 alkyl sulphuric acid is formed, so that the concentration of the 

 total ester [Ba(E,S0 4 ) 2 -f-HE,S0 4 ] undergoing hydrolysis is, at 

 any time t, not (A— a?) but (A — x + 1/2 x), while the concen- 

 tration of the acid accelerating the reaction is (B-f 1/2 x), as is 

 shown in the following equation :* 



Ba(RS0 4 ) 2 + HOH = BaS0 4 + HRS0 4 + ROH 



from which was derived the mathematical expression for the 

 velocity constant, 



dx 



= K(A— 1/2 a;) (B + l/2x) or K 



2X2-3 A(B + l/2a;) 



v lo g 



where A stands for the initial concentration of the alkyl 

 barium sulphate and B that of the hydrochloric acid used, both 

 expressed in gram equivalents per liter. 



Experimental Results. 



Methyl Barium Sulphate 



Table I. 

 BaS0 4 



T = 60° 



in hours 



in grams 



in grm. equiv. 



K 





B 



= 0-25 N HC1 







98-1 



0-1352 



0-0579 





0-00782 



191-2 



0-2597 



0-1113 





0-00772 



268-8 



0-3637 



0-1558 





0-00772 



335-7 



0-4447 



0-1907 





0-00763 



404-7 



0-5285 



0-2264 





0-00761 



481-0 



0-6236 



0-2672 





0-00768 



527-5 



0-6752 



0-2893 





0-00768 



oc 



0-7002 

 B 



0-3000 = 



= 0-5 N HC1 



A 





47-5 



0-1270 



0-0547 





0-00791 



95-5 



0-2510 



0-1075 





0-00791 



168-5 



0-4228 



0-1812 





0-00791 



265-0 



0-6262 



0-2683 





0-00793 



a 



0-6932 



0-2970 = 



A 







* This Journal, xxxii, 53. 







