Gooch and Ensign — Determination of Bromine. 149 



Table X. 



1 1 



KI. 



V © 



= 2 



1 ® 

 KBr=HBr |3 1 1 



s 

 a 



AgBr=HBr 



Error in 



o 



O a 



tr CD 



fc.5 



taken. 



a o 

 i-i t> 



a 



as 



a 



found. 



HBr. 



cm 3 . 

 10 



grm. 

 0-5 



grm. 

 2 



grm. 

 0-5371 



grm. 

 0-3652 



cm- 3 . 

 600 



cm 3 . 

 500 



20 



grm. 



0-8358 



grm. 

 03601 



grm. 

 0-0051 — 



10 



0-5 



2 



0-5367 



0-3647 600 500 



30 



0-8337 



03592 



0-0055- 



10 



0-5 



2 



!e 2 (S0 4 ) 3 + HN0 3 

 grm. cm 3 

 2 5 



95365 



0-3647 



600 500 



20 



0-8309 



0-3580 



0-0067 — 



10 



05 



0-5373 



0-3653 



700! 550 



75 



08170 



0-3520 



0-0133- 



10 



0-5 



2 5 



0-5375 



0-3655 ! 700 550 



60 



0-8171 



0-3520 



0-0135- 



In the comparison of the results of these experiments with 

 those of Table IX, it is plain that, though the time of exposure 

 to the boiling temperature is much shorter, the evolution of 

 the iodine is attended by a not inconsiderable disappearance of 

 bromine. This loss is greater in those tests in which the oxi- 

 dation is produced by the combined action of nitric acid and 

 the ferric salt. It is plain that in this form the method is use- 

 less. We tried next the effect of reducing the quantities of 

 the reagents used by one-half, keeping the volume of the liquid 

 the same, and, finding that the process, conducted otherwise 

 exactly as described above, yielded under these new conditions 

 1825 grm. of hydrobromic acid instead of 01827 grm. taken, 

 we began a series of experiments designed to test the effect of 

 varying the amounts of sulphuric acid present. The other con- 

 ditions were kept unchanged. Table XI contains the record of 

 experiments of this sort in which the oxidizing effect was se- 

 cured by the action of nitric acid and a ferric salt. In Table 

 XII are given the results of experiments in which the fumes 

 generated by the action of sulphuric acid upon sodium nitrite 

 were passed into the liquid to set the iodine free. 



Table XL 



1 1 















d >>■ 



C 



r ~ 













a 



•g a> 



PQ 



*— ' 











r-* <u 





S cs 



K 



6 



CO 



KI. 



Fe 2 (S8 4 ): 



+ HN0 3 . 



KBr=HBr 



taken. 



.5 S 

 a 



d vol 

 n cm 



n| AgBr=HBr. 

 'Z '§ found. 



a 













l-H p. 



a- 



s fe, 





■— 















Pq 



H g< 





&3 



cm 3 . 



grm. 



grm. 



cm 3 . 



grm. 



grm. 



cm 3 . 







grm. 



grm. 



grm. 







0-5 



2 



3 



0-5514 



0-3748 



650 



500 



90 



0-8285 



0-3570 0-0178 — 



4 



0-5 



2 



3 



0-5510 



0-3745 



650 



500 



90 10-8378 



3610 0-0135 — 



o 



0-5 



2 



3 



0-5514 



0-3748 



650 



500 



90 i 0-8463 



0-36470-0101 — 



2 



0-5 



2 







0-5504 



0-3741 



650 



500 



90 | 0-8521 



0-3672,00069- 



1 



05 



2 



3 



0-5508 



0-3744 



650 



500 



90 0-8554 



9-368610-0058 — 



