354 



The sulphiiric acid bound to an estergronp, expels the laurinic 

 acid from it under formation of f^lycerine snl[)hnric acid, so that, 

 finally glycerine trisulphuric acid is formed. This may be expressed 

 as follows: 



CH,OOC . R (H,S0J -^ CH,OSO,OH (R . COOH) 



CH OOC . R (H,SO,) -* CH OSO,OH (R . COOH) 



I I 



CH,OOC . R (H.SOJ ^ CH,OSO,OH (R . COOH) 



What takes place now on the other hand in case of esterification 

 in sulphuric acid surroundings? When glycerine, laurinic acid, and 

 sulphuric acid are mixed the glycerine will immediately be bound 

 with the sulphuric acid, but certainly not ö72/y glycerine trisulphuric 

 acid will be formed then. When a molecule of sulphuric acid combines 

 with one of the alcohol groups of the glycerine, the chance is great 

 that the free acid group of the sulphuric acid still combines with a 

 second alcohol group of the same glycerine molecule, and that we 

 therefore get the compounds: 



/O— CH, /O— CH, 



S^ ' ^ I 



' \o— CH and 0,8^ HC— . SO, . OH 



! \ i 



H,C- . SO, . OH \0— CH, 



i.e. sulphates of glycerine mono sulphuric acid. 



We may imagine the esterification of these sulphates as follows: 



CH,— 0. CH, OOC . R (H,SO J 



1 >S0, (R . COOH) + R . COOH (H,S0J | 

 CH — 0^ ^CH 00C.R(H,S0J 



I (1) j ' ' ^' 



CH,— . SO, . OH (R . COOH) ^ CH, OOC . R (H,SO,), 



(2) 



i.e. the two OH groups that are bound to one molecule of H,SO< 

 are esterized at the same time. 



Let us now examine what relation there will be between the 

 relative concentrations of free glycerine and free laurinic acid. Let 

 us put the "constant of velocity" == pk^ for reaction (1), and = I-, 

 for reaction (2), we obtain the following scheme for the esterification : 



A 



p.k] 



(s) (y) (x) (r) 



