Potassium iodate

Potassium iodate IUPAC name potassium iodate Identifiers InChI InChI=1/HIO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 InChIKey JLKDVMWYMMLWTI-REWHXWOFAL Standard InChI InChI=1S/HIO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 Standard InChIKey JLKDVMWYMMLWTI-UHFFFAOYSA-M CAS number [7758-05-6] ChemSpider 22856 Properties Chemical formula KIO3 Molar mass 214.00 g mol−1 Appearance white crystals Density 3.93 g cm−3 Solubility in water 4.74 g/100 ml (0 °C) Structure Space group P1 (No. 1) Lattice constant a = 769.82(4) pm, b = 765.97(2) pm, c = 769.12(5) pm, α = 108.999(5)°, β = 109.745(2)°, γ = 109.085(5)° Hazards EU index number not listed GHS pictograms GHS signal word DANGER GHS hazard statements H272, H302 GHS precautionary statements P210, P220, P221, P264, P270, P280, P301+312, P330, P370+378, P501 Flash point Non-flammable Related compounds Other anions Potassium iodide Potassium periodate Other cations Lithium iodate Sodium iodate Rubidium iodate Caesium iodate Other compounds Potassium biiodate Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Potassium iodate IUPAC name potassium hydrogen bis(iodate) Identifiers InChI InChI=1/2HIO3.K/c2*2-1(3)4;/h2*(H,2,3,4);/q;;+1/p-1 InChIKey ACAYDTMSDROWHW-REWHXWOFAC Standard InChI InChI=1S/2HIO3.K/c2*2-1(3)4;/h2*(H,2,3,4);/q;;+1/p-1 Standard InChIKey ACAYDTMSDROWHW-UHFFFAOYSA-M CAS number [13455-24-8] EC number 236-650-9 ChemSpider 2341255 Properties Chemical formula KIO3·HIO3 Molar mass 389.91 g mol−1 Appearance white crystals Solubility in water 1.33 g/100 ml (15 °C) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Potassium iodate, KIO₃, is a common iodine compound. It is used for the prophylaxis of iodine deficiency, in radiological protection and in analytical chemistry. It has also been used as a flour treatment agent, although this is no longer recommended.

Preparation

Potassium iodate is commercially available in both reagent and analytical grades. It may be prepared by the reaction of elemental iodine with a concentrated aqueous solution of potassium hydroxide: at appropriate concentrations, the potassium iodate will precipitate leaving the by-product potassium iodide in solution.

I₂ + 6 KOH → KIO₃ + 5 KI + 3 H₂O

Potassium iodate can also be prepared by the high-pressure oxidation of KI with oxygen at 600 °C or by the reaction of elemental iodine with potassium chlorate.

2 KI + 3 O₂ → 2 KIO₃

I₂ + 2 KClO₃ → 2 KIO₃ + Cl₂

External links

• FAO/WHO Joint Expert Committee on Food Additives (JECFA) evaluation (summary): Potassium iodate
• FAO/WHO Joint Expert Committee on Food Additives (JECFA) monograph: Iodine (WHO Food Additives Series 24)