Hydrogenoxalate or hydrogen oxalate (IUPAC name: 2-Hydroxy-2-oxoacetate) is an anion with chemical formula HC2O−4 or HO−C(=O)−CO−2, derived from oxalic acid by the loss of a single proton; or, alternatively, from the oxalate anion C2O2−4 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.
| Names | |
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| IUPAC name 2-Hydroxy-2-oxoacetate | |
| Systematic IUPAC name 2-Hydroxy-2-oxoethanoate | |
Other names
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| Identifiers | |
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3D model (JSmol) |
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| 3601755 | |
| ChEBI |
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| ChemSpider |
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| 49515 | |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| HC2O−4 | |
| Molar mass | 89.026 g·mol−1 |
| Conjugate acid | Oxalic acid |
| Conjugate base | Oxalate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
Well characterized salts include sodium hydrogenoxalate (NaHC2O4), potassium hydrogenoxalate (KHC2O4), ammonium hydrogenoxalate ([NH4]+HC2O−4), rubidium hydrogenoxalate (RbHC2O4) and dimethylammonium hydrogenoxalate ([(CH3)2NH]+HC2O−4).
Structure
Most hydrogenoxalate salts are hydrated. For example, potassium hydrogen oxalate crystallizes as 2KHC2O4·H2O. These materials exhibit extended structures resulting from extensive hydrogen bonding and anion-cation interactions. The hydrates dehydrate upon heating:
- 2KHC2O4·H2O → 2 KHC2O4 + H2O
Proton transfer in hydrogen oxalates has been studied.
See also
wikipedia, wiki, encyclopedia, book, library, article, read, free download, Information about Hydrogenoxalate, What is Hydrogenoxalate? What does Hydrogenoxalate mean?