5G Drushel and Linhart — Metallic Alkyl Sulphates. 



of the other two constituents of the reaction mixture, we have 

 from equation 18, 



^ = K[d 1 (A-x) + d s ^x] [clB + d^x]. (20) 



Considering d„ d„ and d A constant for short time intervals, 

 equation 20, on integration, hecomes 



'2X2-3 



K = 



(d i d. 3 A + 2d i d i B-d i d,B)t 



d„B[d l (A-x) + d^x] 



i0g " dM<tJ* + dA*T' , ' 



Obviously the accurate determination of the values of d,, d t 

 and r/ 3 under the necessary conditions is a matter of consider- 

 able difficulty, but, since ethyl sulphuric acid and hydrochloric 

 acid differ very little in their degrees of dissociation, and since 

 the ionization of strong acids is affected but little by the pres- 

 ence of salts of strong acids, (B+%x)d i may be taken as the 

 approximate concentration of hydrogen ions, where d^ is the 

 degree of dissociation of hydrochloric acid. For the approx- 

 imate concentration of ester ions in dilute aqueous hydrochlo- 

 ric acid (A— x+%x)d, may be used, where d l is the degree of 

 dissociation of ethyl barium sulphate in total ester concentra- 

 tion, (A — x+^x), since the decrease in concentration of ester 

 ions due to the formation of barium sulphate and to the depres- 

 sion of ionization resulting from the increasing concentration 

 of ethyl sulphuric acid is in a large measure offset by the 

 increase in ester ions resulting from the continually increasing 

 concentration of the more highly dissociated ethyl sulphuric 

 acid. We may therefore write as an approximately correct 

 expression for the velocity of the reaction on the ionic theory 

 the simpler equation, 



( ^ = K[(A-x + ix)d 1 ] [(JB+fcsK] (22) 



which on integration gives 



K - * X^3 i oe A ( B +^) (23} 



K -^(A + B) [ ° S B(A-$xy (23) 



When the hydrolysis occurs in a strong hydrochloric acid 

 solution, as l/SN and 4N, the reaction probably consists chiefly 

 of the hydrolysis of ethyl sulphuric acid to sulphuric acid, which 

 at once combines with the barium chloride formed by the 

 action of hydrochloric acid upon the ethyl barium sulphate, 

 so that in this case no great error is made by setting the degree 

 of dissociation of the ester equal to that of the hydrochloric 

 acid, i.e., d^=d^. Then equation 22 becomes 



