Periodic Acid: Formula, Characteristics and Properties

He Periodic acid Is any of the various iodine oxides which contain a higher proportion of oxygen than the iodic acid and differ from each other in water content, especially one of the crystalline compounds HIO4 and H5IO6.

Medical definition of periodic acid: Any acid containing strongly oxidizing iodine such as H5IO6 or HIO4.

Periodic Acid: Formula, Characteristics and Properties

Molecular formula


Chemical and physical properties

Calculated properties

  • Molecular weight: 191,908 g / mol
  • XLogP3 -1.3
  • Hydrogen Links: Donor 1
  • Receptor hydrogen bonds: 4
  • Revolving Bond Account: 0
  • Exact mass: 191.892 g / mol
  • Monoisotope mass: 191.892 g / mol
  • Topological Polar Surface: 71.4 A ^ 2
  • Heavy atom count: 5
  • Formal charge: 0
  • Complexity: 114
  • Number of isotopic atoms: 0
  • Physical State: White crystals
  • Melting point: 122 C (decomposes)
  • Specific Gravity: 1.4
  • Solubility in water: Soluble (soluble in alcohol)
  • PH: Acid in solution
  • Vapor density: 7.9
  • Stability: Stable under normal conditions
  • Synonyms: oroperiodic acid; O-Periodic Acid; Iodic acid.

Overview and Applications

Hydriodic acid is the pale yellow aqueous solution of hydrogen iodide gas. Iodine compounds with oxidation state -1 are called iodides such as hydrogen iodide (HI), sodium iodide (NaI), carbon tetraiodide (CI4) and nitrogen triiodide (NI3).

Iodic acid (hydrogen iodate, HIO3) that can be produced by oxidizing I2 with chlorine in an aqueous solution. Iodine is a salt of iodic acid which is called iodate in which the iodine is bound to three oxygen atoms with the formula IO3-.

Examples: potassium iodate (KIO3), silver iodate (AgIO3), and sodium iodate (NaIO3). Iodine Acid (HIO3): Periodic acid is HIO4 (metaperiodic acid) or H5IO6 (orthoperiodic acid).

The prefix"meta"means less water while"ortho"means more water. Orthoperiodic acid can be dehydrated to metaperiodic acid by heating. Periodic acid is a white crystal; Soluble in water and alcohol; Loses water at 100º Celsius. Periodic acid and its salts (potassium and sodium) are used as potent oxidizing agents in organic synthesis.

Periodic acid is applicable in the structural analysis of carbohydrates. Periodic acid is the highest iodine oxacid, in which iodine exists in oxidation state VII. Like all periodates can exist in 2 forms: orthopedic acid, with the chemical formula H5IO6 and meta-periodic acid, which has the form HIO4. The periodic acid was discovered by Heinrich Gustav Magnus and C.F. Ammermüller in 1833.

Periodic acid is involved in:

  • Synthesis of alkali metal iodates
  • Oxidation of organic halides, sulphides and sulphoxides.
  • In situ generation of iodine.
  • Chemical polymerization of aniline.

Some applications of periodic acid to the study of hydroxyamino acids of protein hydrolysates

  • The release of acetaldehyde and higher aldehydes by periodic acid.
  • Detection and isolation of formaldehyde released by periodic acid.
  • Ammonia is separated from the hydroxyamino acids by periodic acid.

Overview of iodine

Iodine is a nonmetallic halogen element of group 17 of the periodic table.

  • Atomic number: 53
  • Atomic mass: 126.9
  • Melting point: 114 C
  • Boiling point: 184 ° C
  • Specific weight: 4.93 g / cm3
  • Oxidation states: 7, 5.1, -1; [Kr] 4d10 5s2 5p5.

Iodine is a nearly toxic, corrosive, almost black solid at room temperature and easily emits a deep violet vapor whose color is responsible for its Greek name.

It is insoluble in water and soluble in common solvents. Iodine is required in small amounts in the human body for the function of the thyroid gland. Iodine forms many important iodine compounds such as iodine (V) oxide, potassium iodide, iodine trichloride and iodoform of an iodine-containing organic compound.

The related name, iodate, indicates any iodic acid salt containing the radical IO 3 -; KIO3 (potassium iodate) and NaIO3 (sodium iodate) and are the most important salts. The iodide indicates any iodine compound with a more electropositive element or group such as CH3CH2I or any binary iodine compound which may contain the radical I- and which may be considered to be derived from hydro acid (HI). KI and NaI are examples.

Dietary iodine reduces to iodide, is absorbed in the intestines, and is later collected from the bloodstream by the thyroid gland for its incorporation into thyroid hormones. Iodine is applied in the treatment of the thyrotoxic crisis to produce a thyroid gland of firm texture suitable for the operation, it avoids the increase of the vascularity and the friability of the gland with risk of hemorrhage.

Iodine has a powerful bactericidal activity. It is used to disinfect the skin and to treat minor wounds and abrasions. Iodine has been used in the purification of drinking water in case of amebicidal and bactericidal emergencies. Iodine is used as a component in germicides and disinfectants with surfactants to transport iodine. Iodine is used in the treatment of herpes simplex, and prevents the development of goitre.

The inorganic iodide compounds are water soluble and hygroscopic except for a few inorganic iodides such as copper iodide. Their refractive indexes and specific gravity are superior to the corresponding chlorine and bromine analogues. Commercially important iodides are potassium iodide (KI), sodium iodide (NaI), hydrogen iodide (HI), and polyiodides.

Potassium and sodium iodide are used in photography and as analytical reagents. They are used in measuring the energy of gamma rays by measuring the amplitude of light pulses generated by electrons that are excited by gamma rays. They are used as nutritional supplements to prevent goiter and other iodine deficiencies in the human body. They are also used in organic synthesis.

Potassium iodide has been used as a mucolytic agent. Potassium iodide is used as a thermal stabilizer and as a catalyst in the manufacture of synthetic fibers. Hydriodic acid is the pale yellow aqueous solution of hydrogen iodide gas; The 59% hydrogen iodide solution has constant boiling. It is a strong acid and reducing agent used as raw material for pharmaceutical products.

Inorganic iodinated compounds, generally prepared by oxidation of iodine with iodic acid or by electrolytic oxidation of iodide solutions, are stable oxidants at room temperature, although they lose oxygen at higher temperatures. Iodic acid (hydrogen iodate), a white crystalline powder, is a strong inorganic acid; Is a highly corrosive oxidizing agent, decomposed at 110 ° C.

It is used as a reducing agent in organic synthesis. Metal iodates are explosive or flammable when they come in contact with organic combustible materials. Commercially important iodates are potassium iodate and calcium iodate.

They are used as analytical reagents and in the manufacture of disinfectants, antiseptics, deodorants, drugs and other iodine compounds, as well as the oxidation of sulfur dyes. They are also used as animal feed.


  1. Chemical Land 21. (2015). Periodic Acid. 7-1-2017, from Website:
  2. Sigma Aldrich. (2010). Periodic Acid. 7-1-2017, from Sigma-Aldrich Co Website:
  3. National Center for Biotechnology Information. PubChem Compound Database; CID = 65185.