288 Gooch and Blake — Estimation of Bromic Acid 



[ 









Table II. 















A 



Time 

















of 



Approxi 





Error in 



KBrOa = 



: Iodine 



KI 



H2SO, 



stand- 



mate 



Iodine 



terms of 



taken. 



taken. 



taken. 



(1:1) 



ing. 



volume. 



found. 



KBrOs 



grm. 



grm. 



grm. 



cm^. 



hrs. 



cm^. 



grm. 



grm. 



■( 1) 0-1410 



0-6423 



1 



5 



none 



150 



0-6223 



0-0044 — 



( 2) 0-1410 



0-6423 



1 



5 



none 



200 



0-5929 



0-0108— 



( 3) 0-1400 



0-6378 



3 



5 



i 



100 



0-6343 



0-0008- 



( 4) 0-1400 



0-6378 



3 



5 



\ 



100 



0-6329 



0-0011- 



( 5) 0-1400 



06378 



3 



5 



i 



100 



6329 



0-0011- 



( 6) 0-1408 



0-6416 



3 



5 



22 



100 



0-6396 



0-0004- 



( 7) 0-1408 



0-6416 



3 



5 



22 



100 



0-6364 



0-0011 — 



( 8) 0-1408 



0-6416 



3 



5 



22 



100 



0-6381 



0-0008- 



( 9) 0-1400 



0-6378 



3 



2-5 



i 



100 



0-6340 



0-0008— 



(10) 0-1400 



0-6378 



3 



2-5 



i 



100 



0-6336 



0-0009— 



(11) 0-1400 



0-6378 



3 



2-5 



i 



JOO 



0-6336 



0-0009— 



(12) 0-1400 



0-6378 



3 



1 



i 



100 



0-6343 



0-0008— 



(13) 0-1400 



0-6378 



3 

 Sp 



0-5 



B 



HCl 



gr.1-18 

 cm^. 



\ 



100 



0-6331 



0-0010— 



(14) 0-1400 



0-6378 



3 



8 



\ 



100 



0-6336 



0-0009— 



(15) 0-1400 



0-6378 



3 



8 



\ 



100 



0-6329 



0.0011— 



(16) 0-1400 



(17) 0-1400 



0-6378 



3 



8 



\ 



100 



0-6336 



0-0009— 



0-6378 



3 



4 



\ 



100 



0-6336 



0.0009— 



(18) 0-1400 



0-6378 



3 



4 



i 



100 



0-6333 



0-0010- 



(19) 0-1400 



0-6378 



3 



4 



i 



100 



0-6340 



0-0008— 



(20) 0-1400 



0-6378 



3 



4 



1 



100 



0-6336 



0-0009— 



(21) 0-1400 



0-6378 



3 



4 



1 



100 



0-6333 



0-0010— 



(22) 0-1400 



0-6378 



3 



4 



1 



100 



0-6336 



0-0009— 



] 



In experiments (1) and (2) the excess of potassium iodide 

 was only about 20 per cent over the amount demanded by 

 theory, the time of standing was only the few minutes required 

 for the manipulation of the process, and the dilution was 

 considerable. It is obvious that under these conditions the 

 reaction is very incomplete. On the other hand, a glance at 

 the table makes it evident that the oxidation in all other 

 experiments, whether in A or B, proceeds to practically the 

 same point, showing similar errors. So it appears that the 

 variation in the amount of acid above the minimum, the kind 

 of acid (whether sulphuric or hydrochloric), and the time 

 above the minimum half-hour, within the limits defined, are 

 without apparent effect upon the reaction in the presence of 

 the amount of potassium iodide used, approximately four times 



