Dithionous acid

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Dithionous acid
Dithionous acid.svg
Dithionous-acid-3D-balls.png
Names
IUPAC name
Dithionous acid
Other names
Hydrosulfurous acid; Hyposulfurous acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
PubChem CID
  • InChI=1S/H2O4S2/c1-5(2)6(3)4/h(H,1,2)(H,3,4) Yes check.svgY
    Key: GRWZHXKQBITJKP-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/H2O4S2/c1-5(2)6(3)4/h(H,1,2)(H,3,4)
    Key: GRWZHXKQBITJKP-UHFFFAOYAX
  • O=S(O)S(=O)O
Properties
H2S2O4
Molar mass 130.144 g/mol
Acidity (pKa)0.35, 2.45 [1]
Conjugate base Dithionite
Related compounds
Related compounds
Oxalic acid
Sodium dithionite
Potassium dithionite
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Dithionous acid is a sulfur oxoacid with the chemical formula H2S2O4. It has not been observed experimentally. [2] It is the conjugate base of the dithionite dianion, S2O42-. Dithionite is a well-known reducing agent.

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Sulfur (also spelled sulphur in British English) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature.

<span class="mw-page-title-main">Sulfuric acid</span> Chemical compound (H₂SO₄)

Sulfuric acid or sulphuric acid, known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is miscible with water.

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

Sulfuric(IV) acid, also known as sulfurous (UK: sulphurous) acid and thionic acid, is the chemical compound with the formula H2SO3.

<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.

Sulfur trioxide (alternative spelling sulphur trioxide, also known as nisso sulfan) is the chemical compound with the formula SO3. It has been described as "unquestionably the most [economically] important sulfur oxide". It is prepared on an industrial scale as a precursor to sulfuric acid.

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

Sodium thiosulfate is an inorganic compound with the formula Na2S2O3·(H2O)(x). Typically it is available as the white or colorless pentahydrate. It is a white solid that dissolves well in water. The compound is a reducing agent and a ligand, and these properties underpin its applications.

In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called comproportionation, also known as synproportionation.

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

Sodium dithionite is a white crystalline powder with a sulfurous odor. Although it is stable in dry air, it decomposes in hot water and in acid solutions.

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

Sodium dithionate Na2S2O6 is an important compound for inorganic chemistry. It is also known under names disodium dithionate, sodium hyposulfate, and sodium metabisulfate. The sulfur can be considered to be in its +5 oxidation state.

<span class="mw-page-title-main">Dithionite</span> Anion

The dithionite is the oxyanion with the formula [S2O4]2−. It is commonly encountered as the salt sodium dithionite. For historical reasons, it is sometimes called hydrosulfite, but it contains no hydrogen and is not a sulfite. The dianion has a steric number of 4 and trigonal pyramidal geometry.

Hyposulfite may refer to:

<span class="mw-page-title-main">Thiosulfate</span> Polyatomic ion (S2O3, charge –2)

Thiosulfate is an oxyanion of sulfur with the chemical formula S2O2−3. Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, such as sodium thiosulfate Na2S2O3 and ammonium thiosulfate (NH4)2S2O3. Thiosulfate salts occur naturally. It rapidly dechlorinates water and is notable for its use to halt bleaching in the paper-making industry. Thiosulfate salts are mainly used in dying in textiles and the bleaching of natural substances.

<span class="mw-page-title-main">Tetrathionate</span>

The tetrathionate anion, S
4
O2−
6
, is a sulfur oxyanion derived from the compound tetrathionic acid, H2S4O6. Two of the sulfur atoms present in the ion are in oxidation state 0 and two are in oxidation state +5. Alternatively, the compound can be viewed as the adduct resulting from the binding of S2−
2
to SO3. Tetrathionate is one of the polythionates, a family of anions with the formula [Sn(SO3)2]2−. Its IUPAC name is 2-(dithioperoxy)disulfate, and the name of its corresponding acid is 2-(dithioperoxy)disulfuric acid. The Chemical Abstracts Service identifies tetrathionate by the CAS Number 15536-54-6.

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

The dithionate (or metabisulfate) anion, S
2
O2−
6
, is a sulfur oxoanion derived from dithionic acid, H2S2O6. Its chemical formula is sometimes written in a semistructural format, as [O3SSO3]2−. It is the first member of the polythionates.

Bleaching of wood pulp is the chemical processing of wood pulp to lighten its color and whiten the pulp. The primary product of wood pulp is paper, for which whiteness is an important characteristic. These processes and chemistry are also applicable to the bleaching of non-wood pulps, such as those made from bamboo or kenaf.

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

Dithionic acid, H2S2O6, is the inorganic compound with the formula H2S2O6. It is the doubly protonated derivative of dithionate, a well-characterized dianion. Dithionic acid is mainly observed and characterized as an aqueous solution.

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

Potassium dithionite or potassium hydrosulfite is a potassium salt of dithionous acid.

<span class="mw-page-title-main">Polythionic acid</span>

Polythionic acid is an oxoacid which has a straight chain of sulfur atoms and has the chemical formula Sn(SO3H)2 (n > 2). Trithionic acid (H2S3O6), tetrathionic acid (H2S4O6) are simple examples. They are the conjugate acids of polythionates. The compounds of n < 80 are expected to exist, and those of n < 20 have already been synthesized. Dithionic acid (H2S2O6) does not belong to the polythionic acids due to strongly different properties.

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

Sulfoxylic acid (H2SO2) (also known as hyposulfurous acid or sulfur dihydroxide) is an unstable oxoacid of sulfur in an intermediate oxidation state between hydrogen sulfide and dithionous acid. It consists of two hydroxy groups attached to a sulfur atom. Sulfoxylic acid contains sulfur in an oxidation state of +2. Sulfur monoxide (SO) can be considered as a theoretical anhydride for sulfoxylic acid, but it is not actually known to react with water.

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

Potassium thiosulfate, commonly abbreviated KTS, is an inorganic compound with the formula K2S2O3. This salt can form multiple hydrates, such as the monohydrate, dihydrate, and the pentahydrate, all of which are white or colorless solids. It is used as a fertilizer.

References

  1. Catherine E. Housecroft; Alan G. Sharpe (2008). "Chapter 16: The group 16 elements". Inorganic Chemistry, 3rd Edition. Pearson. p. 520. ISBN   978-0-13-175553-6.
  2. Drozdova, Yana; Steudel, Ralf; Hertwig, Roland H.; Koch, Wolfram; Steiger, Thomas (1998). "Structures and Energies of Various Isomers of Dithionous Acid, H2S2O4, and of Its Anion HS2O4- 1". The Journal of Physical Chemistry A. 102 (6): 990–996. Bibcode:1998JPCA..102..990D. doi:10.1021/jp972658d.