150 Gooch and Ensign — Determination of Bromine. 



Table XII. 



• KI. 

 c 



GO 



cur. 

 f5 



^5 



5 



I 5 



U 



r± 

 u 



u 



f3 

 |3 



|3 

 13 



\l 



f2 

 ^2 

 12 



(i 



&5 ° 



KBr=HBr .2 § 



taken. "3 -5 



■2 AgBr=HBr 

 found. 



grm. grm. 

 0.5 I 2 



grm. 

 0-5374 



grm . cm-. 

 03654 600 



0-5375 0- 



0-5365 0- 



05361 6- 



0-5106 0- 



0-5506 



5371 



0-5377 



0-5508 0- 



05371 



0-5365 0- 



0-5368 0- 



0-5364 0- 



0-5505 



0-0576 



0-0552 0- 



0-5366 0- 



0-5369 0- 



0-5515 0- 



0-5367 0- 



0-5366 0- 



0-5368 0- 



05515 0- 



•3655 

 •3647 

 •3644 

 •3471 

 •3743 

 •3652 

 •3655 

 •3744 

 •3652 

 •3647 

 •3649 

 •3646 

 •3742 

 •0391 

 •0375 

 •3647i 

 •3650 

 ■37471 

 •3648 

 •3647 

 •3649 

 •3749 



600 

 600 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 

 650 



S s 

 "ra En "g 



I 1 



cm. grm. grm. 

 never less Ab't 0-8460 0-3645 



than 500 30 



... 















































... 















i 



' 



















Error in 

 HBr. 



grm. 

 0-0009- 



1-8447 

 )-8473 

 )-8461 

 1-8070 

 1-8645 

 1-8466 

 1-8473 

 1-8676 

 1-8459 

 1-8465 

 1-8486 

 1-8471 

 1-S690 

 1-0915 

 1-0883 

 1-8478 

 1-8472 

 1-8687 

 1-8494 

 1-8490 

 1-8492 

 1-8763 



0-3639 

 0-3651 

 03645 

 0-3478 

 3725 

 0-3647 

 0-3651 

 0-3737 

 0-3644 

 0-3647 

 (1-3656 

 0-3650 

 0-3744 

 0-0394 

 0-0380 

 0-3654 

 0-3651 

 0-3742 

 0.3660 

 0-3658 

 0-3659 

 0-3776 



•0016 — 

 0004 + 

 •0001 + 

 •0007 + 

 •0018- 

 •0005 — 

 0004- 

 0007- 

 •0008- 

 •0000 

 •0007 + 

 •0004 + 

 0002 + 

 •0003 + 

 •0005 + 

 •0007 + 

 •0001 + 

 ■0005 — 

 •0012 + 

 •0011 + 

 •0010 + 

 ■0027 + 



It is plain that in both processes the loss of bromine dimin- 

 ishes as the amount of sulphuric acid decreases. In the pres- 

 ence of nitric acid and ferric sulphate the point is never 

 reached, within the limits of our experimentation, at which 

 the error is brought within allowable bounds. This mode of 

 attempting the separation of bromine and iodine we therefore 

 abandoned. 



On the other hand the nitrous acid process, fairly successful 

 when the sulphuric acid present is restricted to 5 cm 3 of the 

 half and half acid (or to 2'5 cm 3 of the strong acid), is estab- 

 lished as trustworthy when the sulphuric acid present is held 

 within the limits of 2 cm 3 to 4 cm 3 of the [1 : 1] mixture. The 

 mean error of thirteen determinations in which the proportions 

 last mentioned were preserved is 0, lying between extremes of 

 0-0008 grm. —and 0-0007 grm. +. When the quantity of sul- 

 phuric acid is still further diminished there appears to be a 

 slight tendency to show an apparent excess of the bromide, 

 due in all probability to the retention of a little combined 

 iodine in the solution. The best proportion for practical use 

 is probably 3 cm 3 of the half and half acid to an initial volume 



