Iodine Polyatomic Ions

Polyatomic Ions

Ions are formed when an atom loses or gains an electron. Ions with a higher number of protons than electrons are known to have a net positive charge. These ions are commonly known as cations. Ions with a greater number of electrons than protons, on the other hand, are known to have a net negative charge. These ions are commonly referred to as anions.

If an ion is composed of only one type of atom (each with a positive or negative net charge), it is referred to as an atomic ion or a monatomic ion. If an ion is composed of two or more atoms, it is referred to as a polyatomic ion or a molecular ion.

Table of Contents

• Iodine
• Hypoiodite Ion
• Iodite Ion
• Iodate Ion
• Periodate Ion
• Frequently Asked Questions – FAQs

Iodine

• Iodine, symbol ‘I,’ is a dark grey or purple blackish nonmetallic element with atomic number 53 in the Periodic Table.
• Despite the fact that it can form compounds with many elements, it is the least reactive and most electropositive halogen.
• It is mostly found on Earth as the water-soluble iodide in brine pools and oceans.
• When heated, this element emits a purple colour.
• It is not completely soluble in water and only dissolves in a few solvents, such as carbon tetrachloride.
• Iodine is found naturally in the air, soil, and water. The oceans are the most important source of this element. There are even minerals that contain iodine.
• Iodine is required for proper brain function in humans.

Iodide is a negative anion with the valency of -1. Iodides are iodine compounds with an oxidation state of -1. I^– is the chemical formula for iodide.

Iodine exists as polyatomic ions as well. There are four polyatomic ions which are-

• Hypoiodite Ion
• Iodite Ion
• Iodate Ion
• Periodate Ion

Read more:

Polyatomic Ions List

Common Polyatomic Ions

Hypoiodite Ion

The hypoiodite ion IO^– is a molecule formed by a covalent bond between iodine and oxygen. Since the hypoiodite ion is extremely unstable, it can only exist in solution. It is made by adding iodine to water and raising the pH to around 12 degrees Celsius (so adding a base such as sodium hydroxide).

The main product of this reaction is hypoiodous acid, but some hypoiodite and the conjugate base are also formed. When a hydrogen atom and a hypoiodite ion combine to form IOH, hypoiodous acid is formed.

Iodine is reacted with water to produce the hypoiodite ion.

I₂ +H₂O → IO^– + 2H⁺ + I^–

Iodite Ion

The halite with the chemical formula IO₂^– is the iodite ion, also known as iodine dioxide anion. Iodine has an oxidation state of +3 within the ion.

Iodites (including iodous acid) are extremely unstable and have been observed but never isolated. They will quickly disproportion to molecular iodine and iodates. They have, however, been identified as intermediates in the conversion of iodide to iodate. Iodous acid, with the formula HIO₂, is the acid form of the iodite ion.

Iodate Ion

The anion with the formula IO₃^– is known as an iodate. It is the most common form of iodine found in nature, as it is found in the majority of iodine-containing ores. Iodide salts are frequently colourless.

Iodate has a pyramidal structure. The O–I–O angles range from 97° to 105°, which is slightly less than the O–Cl–O angles found in chlorate. Iodate-containing minerals can be found in Chile’s caliche deposits. Lautarite and brüggenite are the most important iodate minerals, but copper-bearing iodates such as salesite are also known.

Periodate Ion

Periodate is an anion that is made up of iodine and oxygen. It is one of several oxyanions of iodine, the highest in the series, with iodine in oxidation state +7. It can exist in two forms, unlike other perhalogenates such as perchlorate: metaperiodate IO₄^– and orthoperiodate IO₆^5–. Under this regard, it is comparable to the adjacent group’s tellurate ion. It can combine with a variety of counter ions to form periodates, which are also known as periodic acid salts.

In aqueous media, periodate can exist in a variety of forms, with pH being a key variable. The acid dissociation constants of orthoperiodate are numerous. Equilibrium exists for the ortho- and metaperiodate forms as well. As a result, orthoperiodate is sometimes referred to as metaperiodate’s dihydrate.