Chemical Properties
PERIODIC ACID is colourless crystals
Physical properties
In
dilute solution, periodic acid exists as H
+ and IO4
-.
When more concentrated, orthoperiodic acid, H5IO6, is
formed. Note that this compound is essentially a dihydrate,
HIO4·2H2O. This can be obtained as a crystalline
solid. O-periodic acid can be dehydrated to metaperiodic
acid, m-HIO4. Further heating gives di-iodine pentoxide
(I2O5) and O2. The anhydride di-iodine heptoxide,
i.e. I2O7, does not exist in nature but can be formed
synthetically.
Uses
Periodic acid is used as a component for glycoprotein stains. It serves as a pharmaceutical and synthetic intermediate and is used in silk screen printing. It acts as an oxidizing agent especially the cleavage of 1,2 diols to prepare dialdehydes. It has selective oxidation powers which makes it an ideal reagent for the reclamation of silk screens in the printing industry. It finds application in life sciences for the analysis of intracellular polysaccharides like glycogen, starch and cellulose. Furthermore, it is used in the oxidation reactions converting sulfides into sulfones, catalyzed by chromium(VI) oxide and oxidation reactions converting alcohols to aldehydes and ketones.
Uses
In organic synthesis.
Uses
PERIODIC ACID is used as an oxidiser and in the determination of manganese.
Production Methods
A 100-g quantity of Ba3H4(IO6)2 is moistened with 75 ml H2O and treated with 200 ml of colourless nitric acid. The agitated mixture is heated to 60-70°C for an hour and is then cooled to 30-40°C. The precipitated Ba(NO3)2 is filtered off on a glass frit. The residue is washed free of periodate by stirring with concentrated nitric acid. The combined filtrate is evaporated at 60-70°C in an aspirator vacuum [if more Ba(NO3)s separates, it is filtered, and the evaporation continues] until H5IO6 begins to precipitate. After cooling, glistening crystals of periodic acid are formed. Since the solution tends to become supersaturated, it is often necessary to wait a long time. The crystals are filtered off and dried in a vacuum at 50°C. A second crystal crop may be obtained from the mother liquor by evaporation.
Definition
ChEBI: Orthoperiodic acid is an iodine oxoacid. It is a conjugate acid of an orthoperiodate(1-).
Reactions
Paraperiodic acid H5IO6, is obtained from sodium paraperiodate, formed by action of chlorine upon a NaOH solution containing I2. On vacuum drying, paraperiodic acid yields metaperiodic acid, HIO4, and dimesoperiodic acid, H4I2O9; which form heteropoly acids with a number of oxides and acids. The periodic acids and their salts are strong oxidizing agents both with inorganic and organic compounds.
General Description
Periodic acid (H
5IO
6) is an oxoacid of iodine. It is commonly used as an oxidizing agent in organic synthesis for the preparation of useful chemical intermediates. Periodic acid is also used in oxidative cleavage reactions.
Flammability and Explosibility
Not classified
