hy the Direct Action of Arsenioiis Acid, 



291 



should be produced if the whole amount of iodide added were 

 allowed to act upon the arseniate alone. There appears to be 

 no reason whj'a bromate treated by this process should not 

 leave a similar record of its oxidizing power. A mixture of 

 bromate and chlorate should, therefore, in this process, leave a 

 record of the full amount of oxidation of which both together 

 are capable. The following table contains the account of 

 experiments made in this manner upon the sample of bromate 

 the action of which in the iodide method and in the arsenious 

 acid method is recorded in Tables II and III. 







Table IY. 







(H2SO4) (l:l)20=-3; 



initial volume 105 to 170^ 



^3 ; final volume So*^"'^. 







Iodine corre- 











I value sponcling to 



Iodine corre- 



Error in 



KBrOs 



H2KASO4 



of KI AS2O3 



sponding to 



terms of 



taken. 



taken. 



taken. produced. 



KBrOs. 



KBrOa. 



grm. 



grm. 



grm. grm. 



grm. 



grm. 



(1) 0-0700 



9 



0-4146 0-0948 



0-3198 



0-0002 + 



(2) 0-0700 



2 



0-4146 0-0954 



0-3192 



0-0000 



(3) 0-0700 



2 



0-4146 0-0969 



0-3177 



0-0003— 



(4) 0-0700 



2 



0-4146 0-0975 



0-3171 



0-0004— 



(5) 0-1400 



2 



0-7832 0-1458 



0-6374 



0-0001— 



(6) 0-1400 



2 



0-7832 0-1463 



0-6369 



0-0002— 



(7) 0-1400 



9 



0-7832 0-1462 



0-6370 



0-0002- 



The mean error of these determinations, in 



which all 



oxidizing 



material 



is calculated as bromate, is not far from 



0-0001- grm. 



In the case of still another preparation of potassium bromate, 

 made by acting with commercial bromine on potassium 

 hydroxide, crystallizing and recrystallizing several times, 

 determinations by means of arsenious acid and"by the arseniate- 

 iodide process resulted as shown in the following statement : 



Table V. 







Arsenious Acid Method. 











(Volume not exceeding 100^^3 



.) 









AS0O3 



AS2O3 



Error in 



KBrOs 



AsoOs 



H2SO4 Time un- 



oxi- 



terms of 



taken. 



taken. 



(1:1) in changed. 



dized. 



KBr03 



grm. 



grm. 



grm, minutes. grm. 



At the boiling temperature. 



grm. 



grm. 



0-0704 



0-2475 



5 10 0-1241 



0-1234 



0-0010 — 



0-0704 



0-2475 



5 15 0-1239 



0-1236 



0-0009 — 



0-0704 



0-2475 



5 15 0-1236 



0-1239 



0-0007- 



