The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as salts of chlorous acid.

Compounds

The free acid, chlorous acid HClO₂, is the least stable oxoacid of chlorine and has only been observed as an

aqueous solution An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be re ...

at low concentrations. Since it cannot be concentrated, it is not a commercial product. The

alkali metal The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...

and alkaline earth metal compounds are all colorless or pale yellow, with

sodium chlorite Sodium chlorite (NaClO2) is a chemical compound used in the manufacturing of paper and as a disinfectant. Use The main application of sodium chlorite is the generation of chlorine dioxide for bleaching and stripping of textiles, pulp, and pape ...

(NaClO₂) being the only commercially important chlorite. Heavy metal chlorites (Ag⁺, Hg⁺, Tl⁺, Pb²⁺, and also Cu²⁺ and ) are unstable and decompose explosively with heat or shock. Sodium chlorite is derived indirectly from sodium chlorate, NaClO₃. First, the explosively unstable gas chlorine dioxide, ClO₂ is produced by reducing sodium chlorate with a suitable reducing agent such as methanol, hydrogen peroxide, hydrochloric acid or sulfur dioxide.

Structure and properties

The chlorite ion adopts a

bent molecular geometry In chemistry, molecules with a non-collinear arrangement of two adjacent bonds have bent molecular geometry, also known as angular or V-shaped. Certain atoms, such as oxygen, will almost always set their two (or more) covalent bonds in non-colline ...

, due to the effects of the

lone pair In chemistry, a lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bondIUPAC ''Gold Book'' definition''lone (electron) pair''/ref> and is sometimes called an unshared pair or non-bonding pair. Lone ...

s on the chlorine atom, with an O–Cl–O bond angle of 111° and Cl–O bond lengths of 156 pm. Chlorite is the strongest oxidiser of the chlorine oxyanions on the basis of standard half cell potentials.

Uses

The most important chlorite is

(NaClO₂); this is used in the bleaching of textiles, pulp, and paper, however despite its strongly oxidizing nature it is often not used directly being instead used to generate the neutral species chlorine dioxide (ClO₂), normally via a reaction with HCl: :5 NaClO₂ + 4 HCl → 5 NaCl + 4 ClO₂ + 2 H₂O

Other oxyanions

Several oxyanions of chlorine exist, in which it can assume oxidation states of −1, +1, +3, +5, or +7 within the corresponding anions Cl⁻, ClO⁻, , , or , known commonly and respectively as chloride, hypochlorite, chlorite, chlorate, and perchlorate. These are part of a greater family of other chlorine oxides.

References

{{Reflist *''Kirk-Othmer Concise Encyclopedia of Chemistry'', Martin Grayson, Editor, John Wiley & Sons, Inc., 1985 Chlorine oxides

Compounds

Structure and properties

Uses

Other oxyanions

See also

References