Hydrogenoxalate

Last updated
Hydrogenoxalate
Hydrogenoxalate.svg
Names
IUPAC name
Hydrogen ethanedioate
Other names
Hydrogen oxalate
2-Hydroxy-2-oxoacetate
Identifiers
3D model (JSmol)
3601755
ChEBI
49515
PubChem CID
  • InChI=1S/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)/p-1
    Key: MUBZPKHOEPUJKR-UHFFFAOYSA-M
  • C(=O)(C(=O)[O-])O
Properties
C2HO4
Molar mass 89.027 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Hydrogenoxalate or hydrogen oxalate is an anion with chemical formula HC
2
O
4
or HO
2
C–CO
2
, derived from oxalic acid by the loss of a single proton; or, alternatively, from the oxalate anion C
2
O2−
4
by addition of a proton. The name is also used for any salt containing this anion. Especially in older literature, hydrogenoxalates may also be referred to as bioxalates, acid oxalates, or monobasic oxalates. Hydrogenoxalate is amphoteric, in that it can react both as an acid or a base.

Contents

Well characterized salts include sodium hydrogenoxalate  (NaHC
2
O
4
), [1] [2] potassium hydrogenoxalate  (KHC
2
O
4
), [3] ammonium hydrogenoxalate (NH
3
HC
2
O
4
), rubidium hydrogenoxalate (RbHC
2
O
4
) [4] and dimethylammonium hydrogenoxalate ((CH
3
)2NH
2
HC
2
O
4
). [5]

Structure

Most hydrogenoxalate salts are hydrated. For example, potassium hydrogen oxalate crystallizes as 2KHC
2
O
4
·H
2
O
. These materials exhibit extended structures resulting from extensive hydrogen bonding and anion-cation interactions. The hydrates dehydrate upon heating: [3]

2KHC
2
O
4
·H
2
O
→ 2KHC
2
O
4
+ H
2
O

Proton transfer in hydrogen oxalates has been studied. [6]

See also

Related Research Articles

Alkali metal Group of highly-reactive chemical elements

The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. This family of elements is also known as the lithium family after its leading element.

In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions.

Calcium oxalate Calcium compound

Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula CaC2O4. It forms hydrates CaC2O4·nH2O, where n varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate CaC2O4·H2O occurs naturally as the mineral whewellite, forming envelope-shaped crystals, known in plants as raphides. The two rarer hydrates are dihydrate CaC2O4·2H2O, which occurs naturally as the mineral weddellite, and trihydrate CaC2O4·3H2O, which occurs naturally as the mineral caoxite, are also recognized. Some foods have high quantities of calcium oxalates and can produce sores and numbing on ingestion and may even be fatal. Tribes with diets that depend highly on fruits and vegetables high in calcium oxalate, such as in Micronesia, reduce the level of it by boiling and cooking them. They are a constituent in 76% of human kidney stones. Calcium oxalate is also found in beerstone, a scale that forms on containers used in breweries.

Oxalic acid Simplest dicarboxylic acid

Oxalic acid is an organic acid with the IUPAC name ethanedioic acid and formula HO2C−CO2H. It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early investigators isolated oxalic acid from flowering plants of the genus Oxalis, commonly known as wood-sorrels. It occurs naturally in many foods, but excessive ingestion of oxalic acid or prolonged skin contact can be dangerous.

Oxalate Any derivative of oxalic acid; chemical compound containing oxalate moiety

Oxalate (IUPAC: ethanedioate) is an anion with the formula C2O42−. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na2C2O4), and several esters such as dimethyl oxalate (C2O4(CH3)2). It is a conjugate base of oxalic acid. At neutral pH in aqueous solution, oxalic acid converts completely to oxalate.

In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.

Sodium oxalate Chemical compound

Sodium oxalate, or disodium oxalate, is the sodium salt of oxalic acid with the formula Na2C2O4. It is a white, crystalline, odorless solid, that decomposes above 290 °C.

Sodium thioantimoniate Chemical compound

Sodium thioantimoniate is an inorganic compound with the formula Na3SbS4. The nonahydrate of this material is known as Schlippe's salt, named after K. F. Schlippe (1799–1867), These compounds are examples of sulfosalts. They were once of interest as species generated in qualitative inorganic analysis.

Sodium formate Chemical compound

Sodium formate, HCOONa, is the sodium salt of formic acid, HCOOH. It usually appears as a white deliquescent powder.

Sodium thiocyanate Chemical compound

Sodium thiocyanate (sometimes called sodium sulphocyanide) is the chemical compound with the formula NaSCN. This colorless deliquescent salt is one of the main sources of the thiocyanate anion. As such, it is used as a precursor for the synthesis of pharmaceuticals and other specialty chemicals. Thiocyanate salts are typically prepared by the reaction of cyanide with elemental sulfur:

Indium(III) sulfate (In2(SO4)3) is a sulfate salt of the metal indium. It is a sesquisulfate, meaning that the sulfate group occurs 11/2 times as much as the metal. It may be formed by the reaction of indium, its oxide, or its carbonate with sulfuric acid. An excess of strong acid is required, otherwise insoluble basic salts are formed. As a solid indium sulfate can be anhydrous, or take the form of a pentahydrate with five water molecules or a nonahydrate with nine molecules of water. Indium sulfate is used in the production of indium or indium containing substances. Indium sulfate also can be found in basic salts, acidic salts or double salts including indium alum.

Chromium(III) sulfate Chemical compound

Chromium(III) sulfate usually refers to the inorganic compounds with the formula Cr2(SO4)3.x(H2O), where x can range from 0 to 18. Additionally, ill-defined but commercially important "basic chromium sulfates" are known. These salts are usually either violet or green solids that are soluble in water. It is commonly used in tanning leather.

Croconic acid Chemical compound

Croconic acid or 4,5-dihydroxycyclopentenetrione is a chemical compound with formula C5H2O5 or (C=O)3(COH)2. It has a cyclopentene backbone with two hydroxyl groups adjacent to the double bond and three ketone groups on the remaining carbon atoms. It is sensitive to light, soluble in water and ethanol and forms yellow crystals that decompose at 212 °C.

Rhodizonic acid Chemical compound

Rhodizonic acid is a chemical compound with formula C6H2O6 or (CO)4(COH)2. It can be seen as a twofold enol and fourfold ketone of cyclohexene, more precisely 5,6-dihydroxycyclohex-5-ene-1,2,3,4-tetrone.

Acetylenedicarboxylic acid Chemical compound

Acetylenedicarboxylic acid or butynedioic acid is an organic compound (a dicarboxylic acid) with the formula C4H2O4 or HO2CC≡CCO2H. It is a crystalline solid that is soluble in diethyl ether.

Potassium hydrogenoxalate Chemical compound

Potassium hydrogenoxalate is a salt with formula KHC2O4 or K+·HO2C-CO2. It is one of the most common salts of the hydrogenoxalate anion, and can be obtained by reacting potassium hydroxide with oxalic acid in 1:1 mole ratio.

Cerium nitrates Chemical compound

Cerium nitrate refers to a family of nitrates of cerium in the +3 or +4 oxidation state. Often these compounds contain water, hydroxide, or hydronium ions in addition to cerium and nitrate. Double nitrates of cerium also exist.

Sodium hydrogenoxalate Partly deprotonated oxalic acid

Sodium hydrogenoxalate is salt of formula NaHC
2
O
4
, consisting of sodium cations Na+
and hydrogenoxalate anions HC
2
O
4
or -. The anion can be described as the result of removing one hydrogen ion H+
from oxalic acid H
2
C
2
O
4
, or adding one to the oxalate anion C
2
O2−
4
.

The borate oxalates are chemical compounds containing borate and oxalate anions. Where the oxalate group is bound to the borate via oxygen, a more condensed anion is formed that balances less cations. These can be termed boro-oxalates, bis(oxalato)borates, or oxalatoborates or oxalate borates. The oxalatoborates are heterocyclic compounds with a ring containing -O-B-O-. Bis(oxalato)borates are spiro compounds with rings joined at the boron atom.

Yttrium oxalate Chemical compound

Yttrium oxalate is an inorganic compound, a salt of yttrium and oxalic acid with the chemical formula Y2(C2O4)3. The compound does not dissolve in water and forms crystalline hydrates—colorless crystals.

References

  1. Tellgren, Roland; Olovsson, Ivar (1971). "The crystal structures of normal and deuterated sodium hydrogen oxalate monohydrate NaHC2O4·H2O and NaDC2O4·D2O. Hydrogen bond studies XXXVI". The Journal of Chemical Physics. 54: 127–134. Bibcode:1971JChPh..54..127T. doi:10.1063/1.1674582.
  2. Delaplane, R. G.; Tellgren, R.; Olovsson, I. (1984). "Neutron diffraction study of sodium hydrogen oxalate monohydrate, NaHC2O4·H2O, at 120 K". Acta Crystallographica. C40 (11): 1800–1803. doi:10.1107/S0108270184009616.
  3. 1 2 "The decomposition of potassium hydrogen oxalate hemihydrate". Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character. The Royal Society. 125 (799): 635–646. 1929. doi:10.1098/rspa.1929.0192. ISSN   0950-1207.
  4. Hamadène, M.; Kherfi, H.; Guehria-Laidoudi, A. (2006). "The polymeric anhydrous rubidium hydrogen oxalate". Acta Crystallographica. A62: s280. doi: 10.1107/S0108767306094414 .
  5. Diallo, Waly; Gueye, Ndongo; Crochet, Aurélien; Plasseraud, Laurent; Cattey, Hélène (11 April 2015). "Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid)". Acta Crystallographica Section E: Crystallographic Communications. International Union of Crystallography (IUCr). 71 (5): 473–475. doi:10.1107/s2056989015005964. ISSN   2056-9890.
  6. Bosch, Enric; Moreno, Miquel; Lluch, José María (1 January 1992). "The role of coupling in intramolecular proton transfer reactions. The hydrogen oxalate anion as an example". Canadian Journal of Chemistry. Canadian Science Publishing. 70 (1): 100–106. doi:10.1139/v92-017. ISSN   0008-4042.