Iodic acid, HIO3. It is a white water-soluble solid. Its robustness contrasts with the instability of chloric acid and bromic acid. Iodic acid features iodine in the oxidation state +5 and is one of the most stable oxo-acids of the halogens. When heated, samples dehydrate to give iodine pentoxide. On further heating, the iodine pentoxide further decomposes, giving a mix of iodine, oxygen and lower oxides of iodine.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||175.91 g/mol|
|Density||4.62 g/cm3, solid|
|Melting point||110 °C (230 °F; 383 K)|
|269 g/100 mL (20 °C)|
|Main hazards||acid, corrosive, oxidant|
|NFPA 704 (fire diamond)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Iodic acid is a relatively strong acid with a pKa of 0.75. It is strongly oxidizing in acidic solution, less so in basic solution. When iodic acid acts as oxidizer, then the product of the reaction is either iodine, or iodide ion. Under some special conditions (very low pH and high concentration of chloride ions, such as in concentrated hydrochloric acid), iodic acid is reduced to iodine trichloride, a golden yellow compound in solution and no further reduction occurs. In the absence of chloride ions, when there is an excess amount of reductant, then all iodate is converted to iodide ion. When there is an excess amount of iodate, then part of the iodate is converted to iodine. It may be used in preparation of ionization to form alkyl halides.
Use in salt industryEdit
|Iodine oxidation state||−1||+1||+3||+5||+7|
|Name||Hydrogen iodide||Hypoiodous acid||Iodous acid||Iodic acid||Periodic acid|
|Formula||HI||HIO||HIO2||HIO3||HIO4 or H5IO6|
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