Calcium oxalate

Calcium oxalate
Calcium oxalate
structure of calcium oxalate dihydrate
Structure of calcium oxalate dihydrate
  Calcium, Ca
  Carbon, C
  Oxygen, O
  Hydrogen, H
Names
Preferred IUPAC name
Calcium oxalate
Systematic IUPAC name
Calcium ethanedioate
Other names
Oxalate of lime
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.008.419 Edit this at Wikidata
EC Number
  • 209-260-1
KEGG
UNII
  • InChI=1S/C2H2O4.Ca/c3-1(4)2(5)6;/h(H,3,4)(H,5,6);/q;+2/p-2 checkY
    Key: QXDMQSPYEZFLGF-UHFFFAOYSA-L checkY
  • InChI=1/C2H2O4.Ca/c3-1(4)2(5)6;/h(H,3,4)(H,5,6);/q;+2/p-2
    Key: QXDMQSPYEZFLGF-NUQVWONBAM
  • C(=O)(C(=O)[O-])[O-].[Ca+2]
Properties
CaC2O4
Molar mass 128.096 g·mol−1
Appearance colourless or white crystals (anhydrous and hydrated forms)
Density 2.20 g/cm3, monohydrate[1]
Melting point 200 °C (392 °F; 473 K) decomposes (monohydrate)
0.61 mg/(100 g) H2O (20 °C)[2]
2.7 × 10−9 for CaC2O4[3]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Harmful, Irritant
GHS labelling:
GHS07: Exclamation mark
Warning
H302, H312
P280
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
1
1
Safety data sheet (SDS) External SDS
Related compounds
Other anions
Calcium carbonate
Calcium acetate
Calcium formate
Other cations
Sodium oxalate
Beryllium oxalate
Magnesium oxalate
Strontium oxalate
Barium oxalate
Radium oxalate
Iron(II) oxalate
Iron(III) oxalate
Related compounds
Oxalic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Scanning electron micrograph of the surface of a kidney stone showing tetragonal crystals of Weddellite (calcium oxalate dihydrate) emerging from the amorphous central part of the stone (the horizontal length of the picture represents 0.5 mm of the figured original)

Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula CaC2O4 or Ca(COO)2. 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. Cultural groups with diets that depend highly on fruits and vegetables high in calcium oxalate, such as those in Micronesia, reduce the level of it by boiling and cooking them.[4][5] They are a constituent in 76% of human kidney stones.[6] Calcium oxalate is also found in beerstone, a scale that forms on containers used in breweries.

  1. ^ Cite error: The named reference Acta was invoked but never defined (see the help page).
  2. ^ Haynes, W., ed. (2015–2016). Handbook of Chemistry and Physics (96th ed.). CRC Press. p. 4-55.
  3. ^ Euler. "Ksp Table: Solubility product constants near 25 °C". chm.uri.edu. Retrieved 10 June 2021.
  4. ^ Arnold, Michael A. (2014). "Pandanus tectorius S. Parkinson" (PDF). Aggie Horticulture. Texas A&M University. Archived from the original (PDF) on 31 August 2021. Retrieved 30 September 2020.
  5. ^ WebMD Editorial. "Foods High in Oxalates". WebMD. Retrieved 30 January 2022.
  6. ^ Singh, Prince; Enders, Felicity T.; Vaughan, Lisa E.; Bergstralh, Eric J.; Knoedler, John J.; Krambeck, Amy E.; Lieske, John C.; Rule, Andrew D. (October 2015). "Stone Composition Among First-Time Symptomatic Kidney Stone Formers in the Community". Mayo Clinic Proceedings. 90 (10): 1356–1365. doi:10.1016/j.mayocp.2015.07.016. PMC 4593754. PMID 26349951.

© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search