471 Gooch evil/ Blumenthal — Iodic Acid Process. 



capable of contaminating the silver chloride precipitated by 

 silver nitrate after reduction. 



The effect of chloric acid substituted for iodic acid will 

 depend upon the conditions of concentration. So far as it may 

 act as an oxidizer in the treatment of potassium iodide, it will 

 tend to produce a positive error in the determination of 

 bromine. So far as it escapes reduction in the treatment of 

 sulphur dioxide and nitrogen trioxide, it will tend to produce 

 ap error of deficiency in the determination of chlorine. 



The extent to which these various possibilities may influence 

 results will depend upon the conditions of action and possible 

 balancing of errors. The experimental results given above 

 show plainly that under the conditions defined the separation 

 of bromine from chlorine in halogen salts by the action of 

 iodic acid, though based upon a reaction ideal in respect to 

 the relation of the oxidation potentials, is vitiated by secondary 

 effects. These effects may be reasonably attributed to the 

 action of small amounts of iodine monochloride and iodine 

 monobromide formed in the interaction of iodic acid and free 

 iodine with hydrochloric acid and hydrobromic acid, or to the 

 action of chloric acid and bromic acid derived from iodine 

 monochloride or bromine monochloride by hydrolysis. 



