Linhart — Hydrolysis of Alky I Metallic Sulphates. 285 



If the reactions are considered strictly ionic they can be repre- 

 sented by a single equation : 



C 2 H 5 SO/ + OH' >C 2 H 5 OH + SO/'. 



In either case, whether the reactions are considered to be 

 molecular or ionic, no concordant constants would be expected, 

 for the equilibrium is continuously shifting from lower to more 

 highly dissociated substances as the barium ions are removed 

 from solution. It might be supposed that this would tend to 

 accelerate the reaction slightly, and thus mislead one to con- 

 sider the reaction to be of the first order. However, Kremann's 

 constants cannot be used to confirm the above supposition, as 

 he did not use the proper formula in his calculations, for it is 

 evident from the above ionic equation that for every gram 

 equivalent of ester decomposed there are formed two gram 

 equivalents of sulphate. Therefore, the concentration of ester 

 at any time t should be represented by A — \ x instead of by 

 A — x. This leads to the expression 



|L =K(A _ ia;) 

 which on integration gives 



K= 2X2 - 3 log A A , 



-A- ^ m 2" X 



where A denotes the initial concentration of ester and x the 

 amount of barium sulphate formed in time t, both expressed 

 in gram equivalents per liter. 



In the first four columns of Tables I and II are given Kre- 

 mann's results as published in the article cited. The constants 

 published in that paper he calculated from a formula* derived 

 on the assumption that the hydrogen ions of the water react 

 directly with the barium ester, and that the OH ions of the 

 sodium hydroxide merely neutralize the ethyl sulphuric acid, 

 forming ethyl sodium sulphate which, according to his obser- 

 vations, is not transformed to sodium sulphate during the 

 entire periods indicated in his tables below under t. In the 

 fifth column are given the constants calculated from the cor- 

 rect formulaf if the reaction were of the first order, and in the 

 sixth column, if the reaction is considered to be of the second 

 order.* It is evident from the figures in Table I, column 6, 

 that if the reaction is of the second order, fairer velocity con- 

 stants are obtained if Kremann's experimental results are 

 substituted in the correct formula.^ No concordant constants, 

 however, can be obtained from his results in Table II ; there 

 is a gradual decrease of about eighteen per cent even if the 

 reaction is considered to be of the third order. § 



* See page 286, note *. f See page 286, note f. 



X See page 286, note \. § See page 284. 



Am. Jour. Sci.— Fourth Series, Vol. XXXV, No. 207.— March, 1913. 

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