Potassium sulfite

Last updated
Potassium sulfite
K2SO3.svg
Names
IUPAC name
Potassium sulfite
Other names
  • E225
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.279 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/2K.H2O3S/c;;1-4(2)3/h;;(H2,1,2,3)/q2*+1;/p-2 X mark.svgN
    Key: BHZRJJOHZFYXTO-UHFFFAOYSA-L X mark.svgN
  • InChI=1/2K.H2O3S/c;;1-4(2)3/h;;(H2,1,2,3)/q2*+1;/p-2
    Key: BHZRJJOHZFYXTO-NUQVWONBAU
  • [O-]S(=O)[O-].[K+].[K+]
Properties
K2SO3
Molar mass 158.26 g/mol
AppearanceWhite solid
Density 2.49 g/cm3 [1]
Soluble
Acidity (pKa)8
−64.0·10−6 cm3/mol
Hazards
Flash point Non-flammable
Related compounds
Other anions
Potassium sulfate
Potassium selenite
Other cations
Sodium sulfite
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium sulfite is the inorganic compound with the formula K2SO3. It is the salt of potassium cation and sulfite anion. It is a white solid that is highly soluble in water. Potassium sulfite is used for preserving food and beverages. [2]

Contents

Production and reactions

Potassium sulfite is produced by the thermal decomposition of potassium metabisulfite at 190 °C: [3]

K2S2O5 → K2SO3 + SO2

Structure

The structure of solid K2SO3, as assessed by X-ray crystallography. The S-O distances are 1.515 Å, and the O-S-O angles are 105.2° [1]

Related Research Articles

<span class="mw-page-title-main">Sulfite</span> Oxyanion with a central atom of sulfur surrounded by 3 oxygen atoms

Sulfites or sulphites are compounds that contain the sulfite ion, SO2−
3
. The sulfite ion is the conjugate base of bisulfite. Although its acid is elusive, its salts are widely used.

<span class="mw-page-title-main">Phosphite anion</span> Ion

A phosphite anion or phosphite in inorganic chemistry usually refers to [HPO3]2− but includes [H2PO3] ([HPO2(OH)]). These anions are the conjugate bases of phosphorous acid (H3PO3). The corresponding salts, e.g. sodium phosphite (Na2HPO3) are reducing in character.

<span class="mw-page-title-main">Sodium metabisulfite</span> Chemical compound

Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na2S2O5. The substance is sometimes referred to as disodium metabisulfite. It is used as a disinfectant, antioxidant, and preservative agent. When dissolved in water it forms sodium bisulfite.

<span class="mw-page-title-main">Sodium sulfite</span> Chemical compound

Sodium sulfite (sodium sulphite) is the inorganic compound with the chemical formula Na2SO3. A white, water-soluble solid, it is used commercially as an antioxidant and preservative. It is also suitable for the softening of lignin in the pulping and refining processes of wood and lignocellulosic materials. A heptahydrate is also known but it is less useful because of its greater susceptibility toward oxidation by air.

<span class="mw-page-title-main">Potassium superoxide</span> Chemical compound

Potassium superoxide is an inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. It is used as a CO2 scrubber, H2O dehumidifier, and O2 generator in rebreathers, spacecraft, submarines, and spacesuits.

<span class="mw-page-title-main">Potassium metabisulfite</span> Chemical compound

Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant. As a disulfite, it is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite has a monoclinic crystal structure.

Potassium hypomanganate is the inorganic compound with the formula K3MnO4. Also known as potassium manganate(V), this bright blue solid is a rare example of a salt with the hypomanganate or manganate(V) anion, where the manganese atom is in the +5 oxidation state. It is an intermediate in the production of potassium permanganate and the industrially most important Mn(V) compound.

<span class="mw-page-title-main">Aluminium selenide</span> Chemical compound

Aluminium selenide is the inorganic compound with the formula Al2Se3.

<span class="mw-page-title-main">Potassium bisulfite</span> Chemical compound

Potassium bisulfite (or potassium hydrogen sulfite) is a chemical mixture with the approximate chemical formula KHSO3. Potassium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of potassium ions and bisulfite ions. It is a white solid with an odor of sulfur dioxide. Attempts to crystallize potassium bisulfite yield potassium metabisulfite, K2S2O5.

<span class="mw-page-title-main">Potassium chlorochromate</span> Chemical compound

Potassium chlorochromate is an inorganic compound with the formula KCrO3Cl. It is the potassium salt of chlorochromate, [CrO3Cl]. It is a water-soluble orange compound is used occasionally for oxidation of organic compounds. It is sometimes called Péligot's salt, in recognition of its discoverer Eugène-Melchior Péligot.

Cobalt(II) cyanide is the inorganic compound with the formula Co(CN)2. It is coordination polymer that has attracted intermittent attention over many years in the area of inorganic synthesis and homogeneous catalysis.

<span class="mw-page-title-main">Disulfite</span> Chemical compound

A disulfite, commonly known as metabisulfite or pyrosulfite, is a chemical compound containing the ion S
2
O2−
5
. It is a colorless dianion that is primarily marketed in the form of sodium metabisulfite or potassium metabisulfite. When dissolved in water, these salts release the hydrogensulfite HSO
3
anion. These salts act equivalently to sodium hydrogensulfite or potassium hydrogensulfite.

<span class="mw-page-title-main">Sodium bisulfite</span> Chemical compound

Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO3. Sodium bisulfite in fact is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions. It appears in form of white or yellowish-white crystals with an odor of sulfur dioxide. Regardless of its ill-defined nature, sodium bisulfite is used in many different industries such as a food additive with E number E222 in the food industry, a reducing agent in the cosmetic industry, and a decomposer of residual hypochlorite used in the bleaching industry.

<span class="mw-page-title-main">Ammonium carbamate</span> Chemical compound

Ammonium carbamate is a chemical compound with the formula [NH4][H2NCO2] consisting of ammonium cation NH+4 and carbamate anion NH2COO. It is a white solid that is extremely soluble in water, less so in alcohol. Ammonium carbamate can be formed by the reaction of ammonia NH3 with carbon dioxide CO2, and will slowly decompose to those gases at ordinary temperatures and pressures. It is an intermediate in the industrial synthesis of urea (NH2)2CO, an important fertilizer.

<span class="mw-page-title-main">Chevreul's salt</span> Chemical compound

Chevreul's salt (copper(I,II) sulfite dihydrate, Cu2SO3•CuSO3•2H2O or Cu3(SO3)2•2H2O), is a copper salt which was prepared for the first time by a French chemist Michel Eugène Chevreul in 1812. Its unusual property is that it contains copper in both of its common oxidation states, making it a mixed-valence complex. It is insoluble in water and stable in air. What was known as Rogojski's salt is a mixture of Chevreul's salt and metallic copper.

<span class="mw-page-title-main">Azanide</span> Anion derived from deprotonation of ammonia

Azanide is the IUPAC-sanctioned name for the anion NH−2. The term is obscure; derivatives of NH−2 are almost invariably referred to as amides, despite the fact that amide also refers to the organic functional group –C(=O)−NR2. The anion NH−2 is the conjugate base of ammonia, so it is formed by the self-ionization of ammonia. It is produced by deprotonation of ammonia, usually with strong bases or an alkali metal. Azanide has a H–N–H bond angle of 104.5°.

Nickel dicyanide is the inorganic compound with a chemical formula Ni(CN)2. It is a gray-green solid that is insoluble in most solvents.

A sulfite sulfate is a chemical compound that contains both sulfite and sulfate anions [SO3]2− [SO4]2−. These compounds were discovered in the 1980s as calcium and rare earth element salts. Minerals in this class were later discovered. Minerals may have sulfite as an essential component, or have it substituted for another anion as in alloriite. The related ions [O3SOSO2]2− and [(O2SO)2SO2]2− may be produced in a reaction between sulfur dioxide and sulfate and exist in the solid form as tetramethyl ammonium salts. They have a significant partial pressure of sulfur dioxide.

<span class="mw-page-title-main">Potassium tetracyanonickelate</span> Chemical compound

Potassium tetracyanonickelate (IUPAC: Potassium tetracyanido nickelate(II)) is the inorganic compound with the formula K2Ni(CN)4. It is usually encountered as the monohydrate but the anhydrous salt is also known. Both are yellow, water-soluble, diamagnetic solids. The salt consists of potassium ions and the tetracyanonickelate coordination complex, which is square planar. The [Ni(CN)4]2- anions are arranged in a columnar structure with Ni---Ni distances of 4.294 Å, which is well beyond the sum of the van der Waals radius of the nickel cation. This columnar structure resembles those of the other [M(CN)4]2- anions of the heavy congeners of the group 10 metals (M = Pd, Pt).

A nitrate nitrite, or nitrite nitrate, is a coordination complex or other chemical compound that contains both nitrite and nitrate anions (NO3 and NO2). They are mixed-anion compounds, and they are mixed-valence compounds. Some have third anions. Many nitrite nitrate compounds are coordination complexes of cobalt. Such a substance was discovered by Wolcott Gibbs and Frederick Genth in 1857.

References

  1. 1 2 Andersen, Leif; Strömberg, Dan; Nevala, H.; Pohjola, S.; Niinistö, Lauri; Volden, Hans V.; Weidlein, Johann; Zingaro, Ralph A. (1986). "The Structure of Potassium Sulfite". Acta Chemica Scandinavica. 40a: 479–480. doi: 10.3891/acta.chem.scand.40a-0479 .
  2. "Potassium sulfite (225)". Codex Alimentarius. Food and Agriculture Organization of the United Nations.
  3. Johnstone, H. F. (1946). "Sulfites and Pyrosulfites of the Alkali Metals". Inorganic Syntheses. Vol. 2. pp. 162–167. doi:10.1002/9780470132333.ch49. ISBN   9780470132333.