Title: Iodine Pentoxide
CAS Registry Number: 12029-98-0
Additional Names: Iodic anhydride
Molecular Formula: I2O5
Molecular Weight: 333.81
Percent Composition: I 76.03%, O 23.96%
Literature References: Prepd by thermal dehydration of iodic acid at 195°: Lamb et al., J. Am. Chem. Soc. 42, 1644 (1920). Crystal structure: Selte, Kjekshus, Acta Chem. Scand. 24, 1912 (1970).
Properties: Needle shaped, hygroscopic crystals (an impure product may have a pink cast). d25 5.08. Decompn into I2 and O2 begins at 275° and proceeds rapidly at 350°. Very sol in water (187.4 g/100 ml at 13°) forming HIO3. Insol in abs alc, ether, chloroform, carbon disulfide. Dissolves in nitric acid from which it crystallizes as I2O5 if the HNO3 concn is >50%. Strong oxidizing agent, may detonate when triturated with oxidizable matter. Keep well closed and protected from light.
Density: d25 5.08
Use: Oxidizes carbon monoxide to carbon dioxide with the formn of iodine (Ditte's reaction, which proceeds rapidly at 65° or above, but slowly at room temp). This reaction is used in gas analysis and for removing carbon monoxide from the air (in respirators preferably in presence of some H2SO4). |