Iodine pentoxide is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

I₂O₅. This

iodine oxide Iodine oxides are chemical compounds of oxygen and iodine. Iodine has only two stable oxides which are isolatable in bulk, iodine tetroxide and iodine pentoxide, but a number of other oxides are formed in trace quantities or have been hypothesized ...

is the

anhydride An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the pa ...

of iodic acid, and the only stable oxide of iodine. It is produced by dehydrating iodic acid at 200 °C in a stream of dry air: :2HIO₃ → I₂O₅ + H₂O

Structure

I₂O₅ is bent with an I–O–I angle of 139.2°, but the molecule has no mirror plane so its

symmetry Symmetry (from grc, συμμετρία "agreement in dimensions, due proportion, arrangement") in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, "symmetry" has a more precise definiti ...

is C₂ rather than C_2v. The terminal I–O distances are around 1.80 Å and the bridging I–O distances are around 1.95 Å.

Reactions

Iodine pentoxide easily oxidises

carbon monoxide Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simpl ...

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

at room temperature: :5 CO + I₂O₅ → I₂ + 5 CO₂ This reaction can be used to analyze the concentration of CO in a gaseous sample. I₂O₅ forms iodyl salts, O₂⁺ with SO₃ and S₂O₆F₂, but iodosyl salts, O⁺ with concentrated

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

. Iodine pentoxide decomposes to iodine (vapor) and oxygen when heated to about 350 °C.G. Baxter and G. Tilley, "A Revision of the Atomic Weights of Iodine and Silver," ''The Chemical News and Journal of Industrial Science; Volumes 99-100'', Royal Society Anniversary Meeting, December 3, 1909, p. 276.
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References

{{DEFAULTSORT:Iodine Pentoxide Iodine compounds Oxides Acidic oxides Oxidizing agents