327 



of tlie reaction product, chiefly condensation products were again 

 obtained. 



We then examined tiie absorption of propylene by more diluted 

 sulphuric acid at higher temperature. The experiments were arranged 

 in the same way as was already described for ethylene. The mixture 

 of piopylene and steam was brought in contact in counter-current 

 with sulphuric acid of definite concentration and definite teniperature 

 in the vertical washing-apparatus; 7.5 litres of propylene mixed 

 with steam were passed in 4 hours through sulphuric acid of55 7„ 

 H,SO^ at 140°. The distillate contained 0.25 gr. isopropyl alcohol. 

 After dilution with water a distillate was obtained from the acid 

 in which 0.27 gr. of isopropylalcohol ') was present. There was, 

 therefore, evidently still isopropylsulpiiuric acid present in the acid. 

 In all 2.6 7» of the total quantity of propylene was, accordingly, 

 obtained as isopropyl alcohol. 



A much greater part of the propylene was, however, decomposed. 

 Separation of carbon took |)lace and formation of sulphur-dioxide. 

 After the experiment 5,3 litres of the 7,5 lities of propylene was 

 found back. Hence 9 '/» of the consumed quantity of propylene was 

 changed into isopropyl alcohol. 



An experiment with sulphuric acid of 45 °/„ H^SO^ and at 

 125 — 130° proceeded in the same way; 6 litres of propylene 

 were passed through, 5 litres of them were obtained after the 

 experiment. Tlie yield of isopropyl alcohol amounted to 0,2 gramme 

 in the dislillale and 0.1 gramme in the acid liquid, together 0,30. 

 gr. i.e. 10 Vo of 'l^ö consumed propylene. Here too a large part of 

 the consumed propylene was carbonised. 



It therefore, appears from these experiments that the hydration of 

 propylene by hot diluted sulphuric acid is possible. The reaction 

 velocity, however, is small, which renders the yield small. Besides 

 the sulphuric acid has a decomposing action on the propylene. If 

 on the other hand the experiment is made with concentrated sul- 

 phuric acid at low temperature, the propylene is quickly attacked, 

 but chiefly transformed into condensation products. 



We have tried therefore the action of other acids. We first 

 investigated the action of benzene sulphonic acid. 6 litres of pro- 

 pylene with steam were passed throngii a concentrated solution 

 of benzene sulphonic acid; in the aqueous distillate of this expe- 

 riment we found 0,25 gr. isopropyl alcohol or about 1'/, 7» of the 

 propylene. Hence in this case too the reaction proceeds slowly. 



') The analysis took place by oxidahon to acetone, and colorimetric deter- 

 mination of this substance. 



