Magnesium oxalate
{{Short description|Magnesium compound}}
{{Chembox
| Name = Magnesium oxalate
| ImageFile = Magnesium oxalate.svg
| ImageSize =
| ImageAlt =
| ImageCaption =
| ImageFile1 =
| ImageSize1 =
| ImageAlt1 =
| ImageCaption1 =
| ImageFile2 =
| ImageSize2 =
| ImageAlt2 =
| ImageCaption2 =
| IUPACName = magnesium oxalate
| SystematicName = magnesium oxalate
| OtherNames = {{unbulleted list|magnesium ethanedioate|ethanedioic acid, magnesium salt (1:1)|(Dihydrate)|magnesium oxalate-2-hydrate|magnesium oxalate dihydrate|oxalic acid magnesium salt dihydrate}}{{cite web |url=https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?q=all&cid=68353#ec |title= Oxalates-Compound Summary|accessdate=16 November 2012}}
|Section1={{Chembox Identifiers
| Abbreviations =
| CASNo = 547-66-0
| CASNo_Comment = {{cite book |title= CRC Handbook of Chemistry and Physics|edition= 93|date=2012–2013}}
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo2 = 6150-88-5
| CASNo2_Comment = (dihydrate)
| CASNo2_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 620U3O59Z6
| UNII2_Ref = {{fdacite|correct|FDA}}
| UNII2 = D674BHV95V
| PubChem = 68353
| ChemSpiderID = 61648
| ChemSpiderID5 =
| ChemSpiderIDOther =
| EINECS = 208-932-1{{cite web |url=http://www.chemical5.com/formulas/cas-547-66-0.html |title= Magnesium Oxalate Chemical Formula, Chemical CAS 547-66-0|accessdate=16 November 2012}}
| EC_number =
| DrugBank =
| KEGG =
| MeSHName =
| ChEBI =
| RTECS =
| SMILES = C(=O)(C(=O)[O-])[O-].[Mg+2]
| InChI = {{unbulleted list|1S/C2H2O4.Mg/c3-1(4)2(5)6;/h(H,3,4)(H,5,6);/q;+2/p-2|1S/C2H2O4.Mg.2H2O/c3-1(4)2(5)6;;;/h(H,3,4)(H,5,6);;2*1H2/q;+2;;/p-2 (Dihydrate)}}{{cite web |url=http://www.americanelements.com/mgoxl.html|title= Magnesium Oxalate|accessdate=16 November 2012}}{{cite web |url=http://webbook.nist.gov/cgi/cbook.cgi?ID=B6000058&Units=SI&Mask=80#IR-Spec|title= Magnesium Oxalate|accessdate=16 November 2012}}
| Beilstein =
| Gmelin =
| 3DMet =}}
|Section2={{Chembox Properties
| Formula = {{unbulleted list|MgC{{sub|2}}O{{sub|4}}|MgC{{sub|2}}O{{sub|4}}•2H{{sub|2}}O (Dihydrate)}}
| MolarMass = {{unbulleted list|112.324 g/mol|148.354 g/mol (Dihydrate)}}
| MeltingPt = between {{convert|420|and|620|C|F K}}
{{convert|150|C|F K}} (dihydrate)
| MeltingPt_notes = both decompose{{cite journal|last=Gadala|first=Ahmed|title=Kinetics of the Decomposition of Hydrated Oxalates of Calcium and Magnesium in Air|journal=Thermochimica Acta|year=1984|volume=74|issue=1–3 |pages=255–272|doi=10.1016/0040-6031(84)80027-1}}
| LogP =
| VaporPressure = {{val|2.51|e=-6|u=mmHg}}
| HenryConstant =
| Solubility = 0.038g/100g H{{sub|2}}O (anhydrous and dihydrate)
| SolubilityProduct = 8.5 × 10−5 for {{chem|Mg|C|2|O|4}}{{Cite web |title=Ksp Table: Solubility product constants near 25 °C |author=Euler |work=chm.uri.edu |date= |access-date=10 June 2021 |url= https://www.chm.uri.edu/weuler/chm112/refmater/KspTable.html |language=English}}
| SolubleOther = insoluble in organics
| AtmosphericOHRateConstant =
| pKa =
| pKb =
}}
|Section3={{Chembox Structure
| CrystalStruct =
| Coordination =
| MolShape = }}
|Section4={{Chembox Thermochemistry
| DeltaHc =
| Entropy =
| HeatCapacity = }}
|Section5={{Chembox Pharmacology
| AdminRoutes =
| Bioavail =
| Metabolism =
| HalfLife =
| ProteinBound =
| Excretion =
| Legal_status =
| Legal_US =
| Legal_UK =
| Legal_AU =
| Legal_CA =
| Pregnancy_category =
| Pregnancy_AU =
| Pregnancy_US = }}
|Section6={{Chembox Explosive
| ShockSens =
| FrictionSens =
| DetonationV =
| REFactor = }}
|Section7={{Chembox Hazards
| ExternalSDS =
| MainHazards = Irritant
| NFPA-H = 1
| NFPA-F = 0
| NFPA-R = 0
| NFPA-S =
| FlashPt = Not Applicable
| AutoignitionPt = Not Applicable
| ExploLimits =
| LD50 =
| PEL = }}
|Section8={{Chembox Related
| OtherAnions =
| OtherCations =
| OtherFunction =
| OtherFunction_label =
| OtherCompounds = Magnesium Oxide}}
}}
Magnesium oxalate is an organic compound comprising a magnesium cation with a 2+ charge bonded to an oxalate anion. It has the chemical formula MgC{{sub|2}}O{{sub|4}}. Magnesium oxalate is a white solid that comes in two forms: an anhydrous form and a dihydrate form where two water molecules are complexed with the structure. Both forms are practically insoluble in water and are insoluble in organic solutions.
Natural occurrence
Magnesium oxalate has been found naturally near Mill of Johnston, which is located close to Insch in northeast Scotland. This naturally occurring magnesium oxalate is called glushinskite and occurs at the lichen/rock interface on serpentinite as a creamy white layer mixed in with the hyphae of the lichen fungus. A scanning electron micrograph of samples taken showed that the crystals had a pyramidal structure with both curved and striated faces. The size of these crystals ranged from 2 to 5 μm.{{cite journal|last=Wilson|first=M |author2=D. Jones |author3=D.J. Russell |title=Glushinskite, a naturally occurring magnesium oxalate|journal=Mineralogical Magazine|year=1980|volume=43|issue=331 |pages=837–840|doi=10.1180/minmag.1980.043.331.02|bibcode=1980MinM...43..837W |s2cid=128418178 }}
Synthesis and reactions
Magnesium oxalate can by synthesized by combining a magnesium salt or ion with an oxalate.
: Mg2+ + C{{sub|2}}O{{sub|4}}2− → MgC{{sub|2}}O{{sub|4}}
A specific example of a synthesis would be mixing Mg(NO3)2 and KOH and then adding that solution to dimethyl oxalate, (COOCH3)2.{{cite journal|last=Masuda|first=Yoshio|title=Kinetics of the Thermal Dehydration of Magnesium Oxalate Dihydrate in a Flowing Atmosphere of Dry Nitrogen|journal=J. Phys. Chem.|year=1987|volume=91|issue=26 |pages=6543–6547|doi=10.1021/j100310a024}}
When heated, magnesium oxalate will decompose. First, the dihydrate will decompose at 150 °C into the anhydrous form.
: MgC{{sub|2}}O{{sub|4}}•2H2O → MgC{{sub|2}}O{{sub|4}} + 2 H2O
With additional heating the anhydrous form will decompose further into magnesium oxide and carbon oxides between 420 °C and 620 °C. First, carbon monoxide and magnesium carbonate form. The carbon monoxide then oxidizes to carbon dioxide, and the magnesium carbonate decomposes further to magnesium oxide and carbon dioxide.
: MgC{{sub|2}}O{{sub|4}} → MgCO{{sub|3}} + CO
: CO + 1/2 O2 → CO2
: MgCO{{sub|3}} → MgO + CO2
Magnesium oxalate dihydrate has also been used in the synthesis of nano sized particles of magnesium oxide, which have larger surface are to volume ratio than conventionally synthesized particles and are optimal for various applications, such as in catalysis. By using a sol-gel synthesis, which involves combining a magnesium salt, in this case magnesium oxalate, with a gelating agent, nano sized particles of magnesium oxide can be produced.{{cite journal|last=Mastuli|first=Mohd|author2=Roshidah Rusdi |author3=Annie Mahat |author4=Norazira Saat |author5=Norlida Kamarulzaman |title=Sol-Gel Synthesis of Highly Stable Nano Sized MgO from Magnesium Oxalate Dihydrate|journal=Advanced Materials Research|year=2012|volume=545|pages=137–142 |doi=10.4028/www.scientific.net/amr.545.137|s2cid=97071145 }}
Health and safety
Magnesium oxalate is a skin and eye irritant. If inhaled, it will irritate the lungs and mucous membranes. Magnesium oxalate has no known chronic effects nor any carcinogenic effects. Magnesium oxalate is non-flammable and stable, but in fire conditions it will give off toxic fumes. According to OSHA, magnesium oxalate is considered to be hazardous.{{cite web|url=http://ull.chemistry.uakron.edu/erd/Chemicals/28000/26173.html|title=Magnesium Oxalate|accessdate=16 November 2012|archive-url=https://archive.today/20140220114258/http://ull.chemistry.uakron.edu/erd/Chemicals/28000/26173.html|archive-date=20 February 2014|url-status=dead}}{{cite web |url=http://www.hummelcroton.com/msds/msdsp/mgox_p.html|title= Material Safety Data Sheet Magnesium Oxalate|accessdate=16 November 2012}}
See also
References
{{Reflist}}
{{Magnesium compounds}}
{{Oxalates}}
{{DEFAULTSORT:Magnesium oxalate}}