126 Wheeler and Penfield — Alkaline lodates. 



is insoluble in alcohol. The crystals were filtered on a pump 

 and washed with a little cold water and then pressed on paper. 

 An analysis of these dried at 100° gave the following results, 

 the oxygen being determined by difference. 



HI0 3 . 







Calculated for RbIO ; 



Rubidium, 



20-13 



19-58 



Iodine, 



58-12 



5S-19 



Oxygen, 



21-46 



21-99 



Hydrogen, 



•29 



•23 



The reaction which takes place in the preparation of this 

 compound is probably according to the following equation : 



RbCl + 2HI0 3 =RbIO s . HI0 3 + HC1, 



The hydrochloric acid thus liberated reacts on a part of the 

 iodic acid, chlorine is evolyed and the solution becomes } 7 ellow. 

 When heated it does not decrepitate, but melts to a yellow 

 mass, gives off water, then iodine and finally froths with the 

 evolution of oxygen. The residue consists of rubidium iodide. 

 Diacid rubidium iodate, RblO^ . 2HIO s . — For the prepara- 

 tion of this compound 5 grams of RbI0 3 were dissolved in 

 50 cc. of water with the aid of heat, then 13 grams of iodine 

 pentoxide in 50 cc. of water were added, the mixture boiled 

 down to half its volume and allowed to cool. The body sepa- 

 rates as a heavy crystalline powder. It is difficultly soluble in 

 cold water. When dissolved in hot water and. the solution 

 left to crystalline RbI0 3 separates. The product obtained as 

 stated above was separated from the mother liquor by filtering 

 on the pump, washed with a little cold water and dried at 

 100°. 



2HI0 3 . 





Found. 



Calculated for EbIO ; 



Rubidium, 



13-93 14-13 



13-96 



Iodine, 



61-91 62-48 



62-20 



Oxygen, 



23-74 



23-51 



Hydrogen, 



•42 



•33 



This compound does not lose water at 100°. When heated 

 it does not decrepitate, but melts, gives off water, then iodine 

 and oxygen, leaving a residue of rubidium iodide. The com- 

 pound was also obtained by adding 10 cc. of hydrochloric acid 

 sp. gr. l'l to 5 grams of Rbl0 3 in 20 cc. of water. The mix- 

 ture was warmed until all the RbI0 3 dissolved. It gave a 

 faint yellow solution which slowly deepened in color. On 

 standing, a well crystallized product of the compound under 

 consideration was obtained containing 14-13 per cent of rubid- 

 ium and 62*19 per cent of iodine. 



