World Library  
Flag as Inappropriate
Email this Article

Magnesium oxalate

Article Id: WHEBN0037376969
Reproduction Date:

Title: Magnesium oxalate  
Author: World Heritage Encyclopedia
Language: English
Subject: Magnesium phosphate, Dimagnesium phosphate, Magnesium benzoate, Magnesium bicarbonate, Magnesium trisilicate
Publisher: World Heritage Encyclopedia

Magnesium oxalate

Magnesium Oxalate
CAS number 547-66-0[2]
6150-88-5 (Dihydrate) [2]
PubChem 68353 [1]
ChemSpider .html 61648 [1]
EC number 208-932-1[3]
UN number 2811 [4]
Jmol-3D images Image 1
Molecular formula
  • MgC2O4
  • MgC2O4•2H2O (Dihydrate)
Molar mass
  • 112.324 g/mol
  • 148.354 g/mol (Dihydrate)
Appearance white solid [2]
Density 2.45 g/cm3 [5]
Melting point between 420 and 620 °C (788 and 1,148 °F; 693 and 893 K)
150 °C (302 °F; 423 K) (dihydrate) both decompose[7]
Boiling point Not Applicable
Solubility in water 0.038g/100g H2O (anhydrous and dihydrate) [2]
Solubility insoluble in organics
Vapor pressure 2.51*10-6 mm Hg [3]
Std enthalpy of
-1269.0 kJ mol-1 [2]
Main hazards Irritant
NFPA 704
Flash point Not Applicable
Autoignition temperature Not Applicable
Related compounds
Related compounds Magnesium Oxide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)

Magnesium oxalate is an magnesium cation with a 2+ charge bonded to an oxalate anion. It has the chemical formula MgC2O4. 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

Some oxalates can be found in nature and the most known naturally occurring oxalates are whewellite and weddellite, which are calcium oxalates. Magnesium oxalate has been found naturally near Mill of Johnston which is located close to Insch in northeast Scotland. The naturally occurring magnesium oxalate is called glushinskite. The magnesium oxalate was found at the lichen and rock interface on serpentinite. It was found in a creamy white layer which was mixed in with 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.[8]

Synthesis and reactions

Magnesium oxalate can by synthesized by combining a magnesium salt or ion with an oxalate.

Mg+2+C2O4-2 → MgC2O4

A specific example of a synthesis would be mixing Mg(NO3)2 and KOH and then adding that solution to (COOCH3)2.[9] Magnesium oxalate when heated will decompose. First, the dihydrate will decompose at 150 °C into the anhydrous form.

MgC2O4•2H2O → MgC2O4 + 2H2O

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.[7]

MgC2O4 → MgCO3 + CO
CO + 1/2O2 → CO2
MgCO3 → MgO + CO2

Magnesium oxalate dihydrate has also been used in the synthesis of nano sized magnesium oxide. Magnesium oxide is important because it is used as a catalyst, refractory materials, adsorbents, superconductors, and ferroelectric materials. Nano sized particles of magnesium oxide are optimal for some of these uses because of the larger surface area to volume ratio as compared with larger particles. Most common syntheses of magnesium oxide produce fairly large particles, however, the sol-gel synthesis using magnesium oxalate produces highly stable nano sized particles of magnesium oxide. The sol-gel synthesis involves combining a magnesium salt, or in this case magnesium oxalate, with a gelating agent. This process effectively produces nano sized particles of magnesium oxide.[10]

Health and safety

Magnesium oxalate is a skin and eye irritant. If inhaled, it will irritate the lungs and mucus membrane. Magnesium oxalate has no known chronic effects nor any carcinogenic effects. If magnesium oxalate does come in contact with skin or eyes, flush with water for at least 15 minutes and call a physician if irritation occurs. If inhaled, go to fresh air and call a physician. If swallowed, call a physician immediately. If a spill occurs wash with water and make sure that no dust is released into the air. Dispose of the wash water accordingly. Whenever working with magnesium oxalate, safety goggles, boots, and a lab apron should be worn. If there is dust in the air, a respirator should be worn also. 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.[4][11]


  1. ^ a b c d e "Oxalates-Compound Summary". Retrieved 16 November 2012. 
  2. ^ a b c d e f g CRC Handbook of Chemistry and Physics (93 ed.). 2012–2013. 
  3. ^ a b c "Magnesium Oxalate Chemical Formula, Chemical CAS 547-66-0". Retrieved 16 November 2012. 
  4. ^ a b "Magnesium Oxalate". Retrieved 16 November 2012. 
  5. ^ a b "Magnesium Oxalate". Retrieved 16 November 2012. 
  6. ^ "Magnesium Oxalate". Retrieved 16 November 2012. 
  7. ^ a b Gadala, Ahmed (1984). "Kinetics of the Decomposition of Hydrated Oxalates of Calcium and Magnesium in Air". Thermochimica Acta 74: 255–272.  
  8. ^ Wilson, M; D. Jones, D.J. Russell (1980). "Glushinskite, a naturally occurring magnesium oxalate". Mineralogical Magazine 43: 837–840.  
  9. ^ Masuda, Yoshio (1987). "Kinetics of the Thermal Dehydration of Magnesium Oxalate Dihydrate in a Flowing Atmosphere of Dry Nitrogen". J. Phys. Chem. 91: 6543–6547.  
  10. ^ Mastuli, Mohd; Roshidah Rusdi; Annie Mahat; Norazira Saat; Norlida Kamarulzaman (2012). "Sol-Gel Synthesis of Highly Stable Nano Sized MgO from Magnesium Oxalate Dihydrate". Advanced Materials Research 545: 137–142.  
  11. ^ "Material Safety Data Sheet Magnesium Oxalate". Retrieved 16 November 2012. 

See also

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.