5012. Iodic Acid

Nomenclature

CAS number: 7782-68-5
Iodic acid (HIO3); hydrogen iodate.
HIO3; mol wt 175.91.
H 0.57%, I 72.14%, O 27.29%.

Description and references

Prepd by the oxidation of iodine with nitric acid, perchloric acid, or hydrogen peroxide: Baxter, Tilley, Z. Anorg. Allg. Chem. 61, 295 (1909); Lamb et al., J. Am. Chem. Soc. 42, 1643 (1920); Bray, Caulkins, ibid. 53, 44 (1931). Electrolytic method: Willard, Ralston, Trans. Am. Electrochem. Soc. 62, 239 (1932).

Properties

Orthorhombic crystals. Darkens upon exposure to light. d40 4.629. mp 110° (dec). Decompn to HIO3.I2O5 starts at 70° and decompn to I2O5 is complete at 220°. Not hygroscopic, yet very freely sol in water: 269 g/100 ml H2O at 20°; 295 g/100 ml H2O at 40°. Density of aq solns (w/w) at 18°: 1% = 1.0071; 10% = 1.0900; 20% = 1.1969; 40% = 1.4640; 75% = 2.4710. Strong electrolyte, especially when dil. Sol in nitric acid, dil alcohol. Insol in abs alc, ether, chloroform. Keep well closed and protected from light.

Use

Titration standard in analytical chemistry.

Therapeutic Category

Astringent, disinfectant.

Keywords

Antiseptic/Disinfectant; Halogens/Halogen Containing Compounds; Astringent