The Effects of Dilution and the Presence of Sodium 



Salts and Carbonic Acid upon the Titration 



of Hydroxyamine by Iodine. 



By 



Tamemasa Haga, F. C. S., 



Assistant Professor of Chemistry, College of Science, 

 Imperial University. 



Although hydroxyamine is readily oxidisable in solution by 

 many reagents, its estimation volumetrically is more or less inter- 

 fered with by the fact that the products of its oxidation may vary. 

 Meyeringh and others have shown that cupric hydroxide, perman- 

 ganic acid, and other oxidising agents give irregular results. Titra- 

 tion with free iodine in non-acid solutions is the only method which 

 has yet been proved to be fairly reliable. With this method I liave 

 become very familiar in connection with researches carried oat, not 

 only by myself, but by my former colleagues, Mr. Kawakita and Mr. 

 Shimidzu, in conjunction with Dr. Divers, under Avhom Ave had 

 studied, and I have long become aware that it is accurate only wlien 

 some degree of uniformity is maintained in its practice. In order to 

 learn what deviations in the process, as ordinarily carried out, might 

 cause such irregularities as I have at times observed in the results, 

 I made, last winter, a series of estimations of a known quantity of 

 hydroxyammoninm chloride, under definitely varied conditions, the 

 results of which furnish the matter for this communication. 



The volumetric estimation of hydroxyamine is performed by 



