Drushel and Linhart — Metallic Allajl Sulphates. 53 



of ethyl barium sulphate, ethyl sulphuric acid, or hydrochloric 

 acid. A combustion of the dried material showed about 017 

 per cent of carbon to be present. When the ignited precipitate 

 was boiled with water for some time the filtrate showed traces 

 of barium and chlorine in soluble form, possibly as barium 

 chloride. Frequently some of the precipitated barium sulphate 

 in the hydrolysis tubes was observed to be slightly crystalline, a 

 form favorable under the conditions of hydrolysis for the 

 inclusion of small amounts of impurities. However, the 

 amounts of impurities found in the precipitate after ignition 

 were not deemed sufficient to make it necessary to apply a cor- 

 rection to the weights of the ignited barium sulphate, and these 

 uncorrected weights were accordingly used in the calculation 

 of the velocity constants. 



Theory. — We have found experimentally that both ethyl 

 barium sulphate and ethyl sulphuric acid are fairly stable sub- 

 stances in water solution at room temperature; even at 60° C. 

 the rate of hydrolysis is very slow. Both the salt and the acid 

 were kept in water solution at room temperature for weeks 

 with scarcely any hydrolysis. The hydrolysis of these esters 

 in water may be expressed by the following reactions : From 

 the action of water alone upon the ethyl barium sulphate and 

 ethyl sulphuric acid, 



Ba(C 3 H 6 S0 4 ) 2 + 2H 2 ^=> Ba(OH) 2 + 2HC 2 H 6 S0 4 , (1) 



where the amounts of f>a(OH) 2 and HC 2 H 5 S0 4 are very small, 



and HC 2 H B S0 4 + H 2 +± H 2 S0 4 + C 2 H 6 OH, (2) 



where the equilibrium is approached extremely slowly.* When 

 the two reactions proceed simultaneously barium sulphate is 

 instantly formed, 



Ba(OH) 2 + H,S0 4 > BaS0 4 + 2H 2 0. (3) 



If the second reaction proceeds more rapidly than the first, then 

 a fourth reaction occurs, and we found experimentally that 

 this also is instantaneous. 



Ba(C 2 H 6 S0 4 ) 2 + H 2 S0 4 > BaS0 4 + 2HC 2 H 6 S0 4 . (4) 



The concentration of sulphuric acid in the reaction mixture 

 at any moment must therefore be extremely small, and the 

 increase in the acidity of the mixture must "be wholly due to 

 the accumulation of ethyl sulphuric acid. The whole process 

 of converting ethyl barium sulphate into barium sulphate, ethyl 

 sulphuric acid and ethyl alcohol in water solution may be ex- 

 pressed by the simple reaction : 



* As shown in Table I, series 8. 



