Drusliel and Linhart — Metallic Alkyl Sulphates. 55 



centration of acid accelerating the reaction, we have for the 

 velocity equation : 



^ = K(A-*+*eHB+*r), (11) 



provided that ethyl barium sulphate and ethyl sulphuric acid are 

 esters of similar stability, and that hydrochloric acid and ethyl 

 sulphuric acid have about the same catalytic effect. Both of 

 these conditions were satisfied experimentally, by the slow and 

 similar rates of hydrolysis of ethyl barium sulphate and ethyl 

 sulphuric acid observed in dilute hydrochloric acid, and by the 

 very similar catalytic action of hydrochloric acid and ethyl sul- 

 phuric acid in the hydrolysis of ethyl acetate.* This equation 

 may also be derived from the principle of " the coexistence of 

 reactions," as follows: 



j j 



dx l /dt=K l (A-x)B,iorthe catalysis of Ba(C s H 6 S0 4 ) a by HC1, (12) 

 dxJdt=K^x)B, " " " " HC.H.SO, by HC1, (18) 



dx,/dl=K,(A-x)ix, « « Ba(C s H i S0 4 ) 1 byHC 1 H 6 S0 4 , (14) 

 dxJdt=K^{\x)\x, " " " HC,H s S0 4 by itself, (15) 



dx dx 1 + dx^ + dx 3 + dx t , 



then 



dt " dt 



and ~ = K l [(A-x)B + ($x)B]+K t [(A-x)$x + ($x)ix]. (17) 



Since ethyl barium sulphate and ethyl sulphuric acid are 

 esters of nearly like stability, and hydrochloric acid and ethyl 

 sulphuric acid are of about the same strength, we may set 

 Kj=K,= K, then equation 17 becomes 



^=K(A-x+ix) {B+ix), (18) 



Civ 



which, on integration, gives the simple expression, 

 2X2-3 A(B + ia;) 



K = «lATB) log S(iW*)- ^ 



It is interesting to consider the reaction, on the theory that 

 the velocity is proportional to the total concentration of ester 

 ions and of hydrogen ions. If d x is the degree of dissociation 

 of the ethyl barium sulphate in the presence of the ethyl sul- 

 phuric acid and the hydrochloric acid in the reaction mixture, d. 2 

 the dissociation of the hydrochloric acid in the presence of the 

 ethyl barium sulphate and the ethyl sulphuric acid, and d 3 the 

 degree of dissociation of the ethyl sulphuric acid in the presence 



* This ester was hydrolyzed at 60° C. by N/10 HC1 and by N/10 HC 2 HS0 4 , 

 obtaining the velocity constants 0'00946 and 0'00955 respectively. 



