Messrs Jones and Richardson, Irreversible linear reactions. 215 



Irreversible simultaneous linear reactions. By EL O. Jones, M. A., 

 Clare College, and 0. W. Richardson, B.A., Trinity College. 



[Read 18 May 1903.] 



The authors have investigated the peculiar decomposition of 

 the phenylhydrazone of oxalacetic acid when heated in aqueous 

 and acid solutions, which was first observed by Fenton and Jones 

 (Trans. Chem. Soc. 1901, lxxix. 91). A complete account of 

 the experiments has been published in the Journal of the Chemical 

 Society (Trans. 1902, lxxxi. 1140). It was shown that the 

 results obtained from a study of the rate of evolution of carbon- 

 dioxide from solutions of the hydrazone in sulphuric acid of 

 varying concentration at a temperature of about 80° C, and also 

 of the amount of carbon-dioxide evolved from the same solutions 

 at 100° C, could be explained by supposing that the hydrazone 

 itself, when heated, lost carbon-dioxide and gave pyuric acid 

 phenylhydrazone, the reaction being monornolecular, but that in 

 presence of hydrogen ions the products of decomposition were 

 pyrazolon carboxylic acid and water. In the latter case the 

 reaction was bimolecular, the velocity of formation of the 

 pyrazolon carboxylic acid being jointly proportional to the con- 

 centration of the oxalacetic acid phenylhydrazone and the con- 

 centration of the hydrogen ions in solution. 



This reaction is an example of what may be called a simul- 

 taneous linear reaction, such a reaction involves the simultaneous 

 production from one substance, of at least two others, whilst the 

 rate of formation of each of these is directly proportional to the 

 amount of the original substance present. In the case under 

 consideration the reactions are irreversible and under these con- 

 ditions the theory is considerably simplified. 



The theory for the case when only two irreversible reactions 

 occur simultaneously has been worked out at some length in the 

 paper quoted above (loc. cit); the theory for cases where any 

 number of irreversible reactions take place simultaneously, 

 however, presents no further difficulty. The authors anticipate 

 that several other substances will be found to undergo this type 

 of reaction, under certain conditions, and have therefore developed 

 the theory for the general case, which is here presented. 



