Copper(II) oxalate
Chemical compound
From Wikipedia, the free encyclopedia
Copper(II) oxalate is an inorganic compound with the chemical formula CuC2O4•(H2O)x. The value of x lies between 0 (anhydrous form) and 0.44. One of these species is found as the secondary mineral moolooite (0.44 hydrate).[4] The anhydrous compound has been characterized by X-ray crystallography.[5] Many transition metal oxalate complexes are known.
_Oxalate_Structural_Formula_V1.svg)
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| Names | |
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| Other names
Copper (II) oxalate, cupric oxalate, copper(2+) ethanedioate | |
| Identifiers | |
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3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.011.283 |
| EC Number |
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PubChem CID |
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| UNII | |
| UN number | 3077 |
CompTox Dashboard (EPA) |
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| Properties | |
| CuC 2O 4 | |
| Molar mass | 151.56 |
| Appearance | blue solid |
| Density | 6.57 g/cm3 |
| insoluble | |
Solubility product (Ksp) |
4.43×10−10[1] |
| Hazards | |
| GHS labelling: | |
 [2] | |
| Warning | |
| H302, H302+H312, H312 | |
| P264, P270, P280, P301+P312, P302+P352, P312, P322, P330, P363, P501 | |
| Thermochemistry | |
Std enthalpy of formation (ΔfH⦵298) |
−751.3 kJ/mol[3] |
| Related compounds | |
Related compounds |
Calcium oxalate Sodium oxalate Magnesium oxalate Strontium oxalate Barium oxalate Iron(II) oxalate Iron(III) oxalate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Copper(II) oxalate, whether anhydrous or hydrated, is practically insoluble in all solvents, as it is a coordination polymer.[6]
Synthesis
Copper(II) oxalate can be produced by precipitation from acidified aqueous copper(II) salts and oxalic acid or an alkali metal oxalate.[7][8]
- CuSO4 + H2C2O4 + H2O → CuC2O4·H2O + H2SO4
Reactions
Upon heating to 130 °C, the hydrated copper(II) oxalates convert to the anhydrous cupric oxalate. Further heating at higher temperatures under an atmosphere of hydrogen gives copper metal, suitable as a reagent.[7]
The hydrates bind Lewis bases.
Hydrated copper(II) oxalate reacts with alkali metal oxalates and ammonium oxalate to give bis(oxalato)cuprate:[9]
- (CuC2O4)(H2O)x + C2O2−4 → [Cu(C2O4)2]2− + x H2O
Uses
Copper oxalate is used as a catalyst for organic reactions, as a stabilizer for acetylated polyformaldehyde.[10][11]
Related compounds
- Cuprous oxalates.[12]