152 Jamieson — Determination of Hydrogen Peroxide. 



To, 



CCH2O2 



sol. 

 taken 



CCN/IOAS2O3 



sol. 



taken 



CCKIO3 



sol, 



used 



CCAS2O3 



sol, 



used by H2O2 



H2O2 

 found 

 grams 



Kingzett 

 method 



1 



15-1 



34-9 



4-9 



31-6 



•0537 





2 



15-0 



34-9 



5-02 



31-55 



•0536 



•0536 



3 



20-0 



46-0 



6-0 



42-0 



•0*714 



•0710 



4 



20-0 



45-5 



5-45 



41-9 



•0712 





5 



22-0 



49-9 



5-90 



46-0 



■0782 



•0781 



6 



22-0 



49-9 



5-90 



46-0 



•0782 



. •0781 



These titrations were made during a period of three hours 

 after preparing the diluted hydrogen peroxide. It is important 

 to titrate the hydrogen peroxide solution which has been 

 diluted with ordinary distilled water of the laboratory soon 

 after the dilution because it was observed that the h^^drogen 

 peroxide slowly decomposed. A diluted solution of hydrogen 

 peroxide was prepared and analyzed. It was found to contain 

 •003639 g. of II2O2 per cc. After standing 24 hours it con- 

 tained •003551 g. of II2O2 per cc. and a week later it was found 

 to contain only a trace of peroxide. 



Another solution was prepared by diluting 55^*^ of the com- 

 mercial hydrogen peroxide to 500^^^ which gave the following 

 results upon analysis : 



To. 



CCH2O2 

 sol. 



CCN/IOAS2O3 

 sol. 



CCKIO3 

 used 



CCAS2O3 



sol. 



used by H2O2 



H2O2 

 found 



Kingzett 

 det's. 



] 



15-2 



40^0 



7-05 



35^3 



•0600 



•0602 



2 



15-0 



39-9 



7^35 



35-0 



•0595 



•0595 



3 



15^05 



39-9 



7-35 



35^0 



•0595 



•0597 



4 



15-20 



39-8 



6-70 



35^3 



•0600 





5 



15^10 



39^8 



7-00 



35^13 



•0597 



•0598 



The results obtained in each series of experiments show 

 that the method gives accurate results. In practice, it would 

 be recommended that a fifth normal sodium arsenite solution 

 along with an equivalent potassium iodate solution (lO^TOOg. 

 of KlOg per 1000'^) should be employed. 



Yale University, New Haven, Ct. 



