Drushel and Linhart — Metallic Alkyl Sulphates. 51 



Art. VIII. — On the Hydrolysis of Metallic AlJcyl Sulphates ; 

 by W. A. Drushel and Gr. A. Linhart. 



[Contributions from Kent Chemical Laboratory of Yale University. — ccxxi.] 



I. Ethyl Barium Sulphate* 



In a recent article in Monatshefte fur Chemief results were 

 published which lead to the unexpected conclusion that the 

 velocity of the decomposition of ethyl barium sulphate in water 

 solution is retarded by the presence of dilute hydrochloric acid. 

 In preliminary experiments we were unable to obtain results in 

 accord with this conclusion, but, on the contrary, found that 

 ethyl barium sulphate is converted into barium sulphate more 

 rapidly in any concentration of hydrochloric acid than in water 

 alone, the velocity corresponding approximately to the concen- 

 tration of acid used. These preliminary results suggested the 

 desirability of making a further study of the velocity of the 

 reaction in water alone and in varying concentrations of hydro- 

 chloric acid. 



From our hydrolysis experiments with water in the absence 

 of hydrochloric acid it was found that the rate of precipitation 

 of barium sulphate, under conditions similar to those mentioned 

 in the article cited, is only a little more than one milligram per 

 21 hours during a period of more than 30 days,:}: so that, at tliis 

 rate, it would require about 650 days for the precipitation of 

 721 mgrm., instead of 1,300 minutes (about 3 days) as found by 

 Kremann. On the assumption that ethyl barium sulphate is 

 decomposed more rapidly in water alone than in half normal 

 hydrochloric acid but less rapidly than in normal acid, Kre- 

 mann§ obtained for the velocity of the reaction an expression 

 too complex to solve for the velocity constant. It is the pur- 

 pose of this paper to show that the reaction does not yield 

 unexpected results, and that it may be expressed in a velocity 

 equation from which satisfactory constants may be calculated. 



Preparation and analysis of the salt. — Fuming sulphuric 

 acid was introduced drop by drop into absolute ethyl alcohol 

 cooled in an ice bath. When the requisite amount of sulphuric 

 acid had been added the ice bath was replaced by a water bath 

 which was kept at the boiling temperature for two hours. The 

 acid mixture was now diluted with water to about five times 

 its volume, neutralized with pure barium carbouate, transferred 

 to a tall cylinder, and allowed to stand until the barium sul- 



* Work has been begun on the methyl and propyl barium sulphates, 

 t E. Kremann, Monatsh. fur Chem. (Ill), xxxi, 165. 

 \ See Table I, p. 57. 

 § Kremann, loc. cit. 



