462 Walker and Gillespie- 



-Ajjjplication of Iodine, etc. 



Table VII. 



N 

 Analyses of — Sulphuric Acid Solution. 



N 10 



(By adding to excess of — Ba(01I).j, boiling with excess of iodine to decoloration, 









and acidifying 



the residue.) 









H 2 S0 4 

 taken. 



Bn(0H) 2 

 taken. 



Ba(OII), 

 neutralized 

 by H a S0 4 . 



II, SO, 

 found. 



Mean. 



Variation. 





cral 



grm. 



* grin. 



grm. 



grm. 



grm. 



(1) 



10 



0'21 



00884 



0*0506 



0-0498 



0-0008 + 



(2) 



10 



0-21 



0-0880 



0-0503 



0-0498 



0-0005 + 



(3) 



15 



0-30 



0-1328 



0-0754 



0-0748 



0-0006 + 



W 



15 



0-30 



0-1313 



0-0751 



0-0748 



0-0003 + 



(5) 



25 



0*43 



02168 



0-1239 



0-1246 



0-0007 — 



(6) 



30 



0*43 



0-2600 



0-1481 



0-1495 



0-0014 — 



This investigation shows that the reaction between iodine 

 and hydroxides of the alkalies and alkaline earths in hot solu- 

 tion is regular and complete under analytical conditions, not 

 being appreciably affected by the mass action of considerable 

 excesses of iodine. The reaction is best applied in analysis by 

 titrating the alkali with an excess of iodine, removing this 

 excess by boiling, and estimating the iodine in the residue. 

 While certain mechanical difficulties may affect the extreme 

 accuracy of the process as a direct means for analyzing alka- 

 lies, the action is at all times regular and may be indirectly 

 applied with fair accuracy to the analysis of various acids and 

 possibly to other compounds. The reaction between iodine 

 and alkali carbonates on the contrary is irregular and cannot 

 be made the basis of any analytical process. 



