Linhart — Hydrolysis of Alkyl Metallic Sulphates. 283 



Art. XXIY. — On the Hydrolysis of Alkyl Metallic Sul- 

 phates ; by G. A. Linhart. 



[Contributions from the Kent Chemical Laboratory of Yale Univ. — ccxli.] 



IV. Sodium, Strontium, and Barium Esters in Alkaline 

 Solutions. 



Attention lias been called to a paper* in which it is claimed 

 that ethyl barium sulphate decomposes at a greater rate in 

 water solution than in half normal aqueous hydrochloric acid, 

 but not quite as rapidly as in normal acid. From these experi- 

 mental results a differential equation too complex for integra- 

 tion is developed, and consequently no velocity constants^ are 

 calculated from the published experimental data. In the 

 paper cited, similar discrepancies appear in Kremann's work 

 with barium ethyl sulphate in alkaline solution. 



From a long series of carefully executed reaction velocity 

 measurements in acid, water and alkaline solutions;); it is evident 

 that not only are Kremann's experimental data unreliable, but 

 likewise his theory must be incorrect. Assuming that the O H 

 ions of the sodium hydroxide used have no appreciable effect 

 on the ethyl barium sulphate in the course of hydrolysis, Kre- 

 mann considers the reaction to be of the first order and repre- 

 sents it by the following equations : 



"Ba(C 9 H 6 S0 4 ), + 2H,0 = BaS0 4 + 2C 2 H 5 OH + H 2 S0 4 

 Ba(C 2 H 5 S0 4 ) 2 + H 2 S0 4 + 2N"aOH=BaS0 4 + 2NaC 2 H 5 S0 4 + 2H 2 0." 



The formation of barium sulphate, Kremann states, is due 

 chiefly to these two reactious, since, according to his observa- 

 tion, the ethyl sodium sulphate resulting from the interaction 

 of the sodium hydroxide and the ethyl sulphuric acid liberated 

 in the course of the hydrolysis of the barium ethyl sulphate 

 does not undergo any appreciable transformation into sodium 

 sulphate during a period of eight days at temperatures of 55° 

 and 66° at which his hydrolases were made. From a pre- 

 liminary experiment§ at 60° I found that ethyl sodium sul- 

 phate is transformed into sodium sulphate during a period of 

 eight days to the extent of about 16 per cent. In his conclu- 



* R. Kremann, Monatsh. fur Chem. (3), xxxi, 165. 



\ It is often possible in such cases to calculate constants directly from the 

 differential equation with a sufficient degree of accuracy by substituting 

 mean values for short time intervals. 



X This Journal, xxxii, 53; xxxiv, 289 and 539. 



§ See p. 288. 



