Periodate can exist in a variety of forms in aqueous media, with pH being a controlling factor. Orthoperiodate has a number of acid dissociation constants. [5] [6] H 5 IO 6 ↽ − − ⇀ H 4 IO 6 − + H + {\displaystyle {\ce {H5IO6 <=> H4IO6- + H+}}} p K a = 3.29 H 4 IO 6 − ↽ − − ⇀ H 3 IO 6 2 − + H + {\displaystyle {\ce {H4IO6- <=> H3IO6 Record of Natriumperiodat in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 2018-01-08.

Sodium periodate is an inorganic salt, composed of a sodium cation and the periodate anion. It may also be regarded as the sodium salt of periodic acid. Like many periodates, it can exist in two different forms: sodium metaperiodate (formula‍NaIO 4) and sodium orthoperiodate (normally Na 2H 3IO 6, but sometimes the fully reacted salt Na 5IO 6). Both salts are useful oxidising agents. [2] Preparation [ edit ]Modern industrial scale production involves the electrochemical oxidation of iodates, on a lead dioxide ( PbO 2) anode, with the following standard electrode potential: NaIO 3 + NaOCl sodium hypochlorite ⟶ NaIO 4 + NaCl {\displaystyle {\ce {NaIO3{}+{\overset {sodium\ hypochlorite}{NaOCl}}->NaIO4{}+NaCl}}} Forms and interconversion [ edit ] Sodium metaperiodate can be prepared by the dehydration of sodium hydrogen periodate with nitric acid. [3] Na 3 H 2 IO 6 + 2 HNO 3 ⟶ NaIO 4 + 2 NaNO 3 + 2 H 2 O {\displaystyle {\ce {Na3H2IO6 + 2 HNO3 -> NaIO4 + 2 NaNO3 + 2 H2O}}} Structure [ edit ]

Jansen, Martin; Rehr, Anette (1988). "Na 2H 3IO 6, eine Variante der Markasitstruktur". Zeitschrift für anorganische und allgemeine Chemie (in German). 567 (1): 95–100. doi: 10.1002/zaac.19885670111. Sodium metaperiodate (NaIO 4) forms tetragonal crystals ( space group I4 1/ a) consisting of slightly distorted IO − In this regard it is comparable to the tellurate ion from the adjacent group. It can combine with a number of counter ions to form periodates, which may also be regarded as the salts of periodic acid.Sodium hydrogen periodate (Na 2H 3IO 6) forms orthorhombic crystals (space group Pnnm). Iodine and sodium atoms are both surrounded by an octahedral arrangement of 6 oxygen atoms; however the NaO 6 octahedron is strongly distorted. IO 6 and NaO 6 groups are linked via common vertices and edges. [7]

Classically, periodate was most commonly produced in the form of sodium hydrogen periodate ( Na 3H 2IO 6). [2] This is commercially available, but can also be produced by the oxidation of iodates with chlorine and sodium hydroxide. [3] Or, similarly, from iodides by oxidation with bromine and sodium hydroxide: Parsons, Roger (1959). Handbook of electrochemical constants. Butterworths Scientific Publications Ltd. p. 71. They can also be generated directly from iodates by treatment with other strong oxidizing agents such as hypochlorites: Periodates were discovered by Heinrich Gustav Magnus and C. F. Ammermüller; who first synthesised periodic acid in 1833. [1] Synthesis [ edit ] Betz, T.; Hoppe, R. (May 1984). "Über Perrhenate. 2. Zur Kenntnis von Li 5ReO 6 und Na 5ReO 6 – mit einer Bemerkung über Na 5IO 6". Zeitschrift für anorganische und allgemeine Chemie (in German). 512 (5): 19–33. doi: 10.1002/zaac.19845120504.

Log in/register

McMurry, John. Organic chemistry (8th ed., [international ed.]ed.). Singapore: Brooks/Cole Cengage Learning. pp.285–286. ISBN 9780840054531. Hill, Arthur E. (October 1928). "Ternary Systems. VII. The Periodates of the Alkali Metals". Journal of the American Chemical Society. 50 (10): 2678–2692. doi: 10.1021/ja01397a013. H 5 IO 6 + H + + 2 e − ⟶ IO 3 − + 3 H 2 O {\displaystyle {\ce {H5IO6 + H+ + 2e- -> IO3- + 3 H2O}}} E° = 1.6 V [4] a b Riley, edited by Georg Brauer; translated by Scripta Technica, Inc. Translation editor Reed F. (1963). Handbook of preparative inorganic chemistry. Volume 1 (2nded.). New York, N.Y.: Academic Press. pp.323–324. ISBN 012126601X. {{ cite book}}: |first= has generic name ( help) CS1 maint: multiple names: authors list ( link)

Periodate / p ə ˈ r aɪ . ə d eɪ t/ is an anion composed of iodine and oxygen. It is one of a number of oxyanions of iodine and is the highest in the series, with iodine existing in oxidation state +7. Unlike other perhalogenates, such as perchlorate, it can exist in two forms: metaperiodate IO − H 5 IO 6 + H + + 2 e − ⟶ IO 3 − + 3 H 2 O {\displaystyle {\ce {H5IO6 + H+ + 2e- -> IO3- + 3 H2O}}} E° = 1.6 V [5] Metaperiodates are typically prepared by the dehydration of sodium hydrogen periodate with nitric acid, [2] or by dehydrating orthoperiodic acid by heating it to 100 °C under vacuum. Andrew G. Wee, Jason Slobodian, Manuel A. Fernández-Rodríguez and Enrique Aguilar "Sodium Periodate" e-EROS Encyclopedia of Reagents for Organic Synthesis 2006. doi: 10.1002/047084289X.rs095.pub2 Classically, periodate was most commonly produced in the form of sodium hydrogen periodate ( Na 3H 2IO 6). [3] This is commercially available, but can also be produced by the oxidation of iodates with chlorine and sodium hydroxide. [4] Or, similarly, from iodides by oxidation with bromine and sodium hydroxide:Na 3 H 2 IO 6 + 2 HNO 3 ⟶ NaIO 4 + 2 NaNO 3 + 2 H 2 O {\displaystyle {\ce {Na3H2IO6 + 2 HNO3 -> NaIO4 + 2 NaNO3 + 2 H2O}}} H 5 IO 6 ⟶ HIO 4 + 2 H 2 O {\displaystyle {\ce {H5IO6 -> HIO4 + 2 H2O}}} ions with average I–O bond distances of 1.775Å; the Na + ions are surrounded by 8 oxygen atoms at distances of 2.54 and 2.60Å. [6]