When heated at between 200 and 525°C with vanadium pentoxide in a 1:2 molar ratio, the above reaction is suppressed, yielding instead a sodium vanadium oxibronze with release of carbon dioxide[6]
x Na2C2O4 + 2 V2O5 → 2 NaxV2O5 + 2x CO2
with x increasing up to 1 as the temperature increases.
Sodium oxalate is used to standardize potassium permanganate solutions. It is desirable that the temperature of the titration mixture be greater than 60 °C to ensure that all the permanganate added reacts quickly. The kinetics of the reaction are complex, and the manganese(II) ions (Mn2+) formed catalyze the further reaction between permanganate and oxalic acid (formed in situ by the addition of excess sulfuric acid). The final equation is as follows:[7]
Like several other oxalates, sodium oxalate is toxic to humans. It can cause burning pain in the mouth, throat and stomach, bloody vomiting, headache, muscle cramps, cramps and convulsions, drop in blood pressure, heart failure, shock, coma, and possible death. Mean lethal dose by ingestion of oxalates is 10-15 grams/kilogram of body weight (per MSDS).
^ ab"ChemIDplus - 62-76-0 - ZNCPFRVNHGOPAG-UHFFFAOYSA-L - Disodium oxalate - Similar structures search, synonyms, formulas, resource links, and other chemical information". chem.nlm.nih.gov. NIH. Retrieved 7 January 2019.
^ abcdYoshimori T1, Asano Y, Toriumi Y, Shiota T. (1978) "Investigation on the drying and decomposition of sodium oxalate". Talanta, volume 25, issue 10, pages 603-605. doi:10.1016/0039-9140(78)80158-1
^"Natroxolate" (PDF). RRUFF. Mineral Data Publishing. Retrieved 7 January 2019.
^H. W. Foote and John E. Vance (1933), "The system; sodium iodate, sodium oxalate, water". American Journal of Science, series 5, volume 26, issue 151, pages 16-18. doi:10.2475/ajs.s5-26.151.16
^D. Ballivet-Tkatchenko, J. Galy, -M. Savariault (1994): "Thermal decomposition of sodium oxalate in the presence of V2O5: Mechanistic approach of sodium oxibronzes formation". Thermochimica Acta, volume 232, issue 2, pages 215-223. doi:10.1016/0040-6031(94)80061-8
^Mcbride, R. S. (1912). "The standardization of potassium permanganate solution by sodium oxalate". J. Am. Chem. Soc.34 (4): 393–416. doi:10.1021/ja02205a009.
April 27, 2024
sodium, oxalate, disodium, oxalate, chemical, compound, with, chemical, formula, na2c2o4, sodium, salt, oxalic, acid, contains, sodium, cations, oxalate, anions, c2o2, white, crystalline, odorless, solid, that, decomposes, above, names, preferred, iupac, name,. Sodium oxalate or disodium oxalate is a chemical compound with the chemical formula Na2C2O4 It is the sodium salt of oxalic acid It contains sodium cations Na and oxalate anions C2O2 4 It is a white crystalline odorless solid that decomposes above 290 C 2 Sodium oxalate Names Preferred IUPAC name Disodium oxalate Other names Oxalic acid disodium saltSodium ethanedioate Identifiers CAS Number 62 76 0 Y 1 3D model JSmol Interactive image ChEBI CHEBI 132764 N ChEMBL ChEMBL182928 N ChemSpider 5895 N ECHA InfoCard 100 000 501 EC Number 200 550 3 PubChem CID 6125 RTECS number K11750000 UNII 7U0V68LT9X Y CompTox Dashboard EPA DTXSID1037018 InChI InChI 1S C2H2O4 2Na c3 1 4 2 5 6 h H 3 4 H 5 6 q 2 1 p 2 NKey ZNCPFRVNHGOPAG UHFFFAOYSA L N SMILES C O C O O O Na Na Properties Chemical formula Na2C2O4 Molar mass 133 998 g mol 1 Appearance White crystalline solid Odor Odorless Density 2 34 g cm3 Melting point 260 C 500 F 533 K decomposes above 290 C 2 Solubility in water 2 69 g 100 mL 0 C 3 7 g 100 mL 20 C 6 25 g 100 mL 100 C Solubility Soluble in formic acid insoluble in ethanol diethyl ether Structure Crystal structure monoclinic Thermochemistry Std enthalpy offormation DfH 298 1318 kJ mol Hazards GHS labelling 3 Pictograms Signal word Warning Hazard statements H302 H312 Precautionary statements P280 P301 P312 P302 P352 NFPA 704 fire diamond 100 Lethal dose or concentration LD LC LD50 median dose 11160 mg kg oral rat 1 Safety data sheet SDS Oxford MSDS unreliable source Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Sodium oxalate can act as a reducing agent and it may be used as a primary standard for standardizing potassium permanganate KMnO4 solutions The mineral form of sodium oxalate is natroxalate It is only very rarely found and restricted to extremely sodic conditions of ultra alkaline pegmatites 4 Contents 1 Preparation 2 Reactions 3 Biological activity 4 ReferencesPreparation editSodium oxalate can be prepared through the neutralization of oxalic acid with sodium hydroxide NaOH in a 1 2 acid to base molar ratio Evaporation yields the anhydrous oxalate 5 that can be thoroughly dried by heating to between 200 and 250 C 2 Half neutralization can be accomplished with NaOH in a 1 1 ratio which produces NaHC2O4 monobasic sodium oxalate or sodium hydrogenoxalate Alternatively it can be produced by decomposing sodium formate by heating it at a temperature exceeding 360 C citation needed Reactions editSodium oxalate starts to decompose above 290 C into sodium carbonate and carbon monoxide 2 Na2C2O4 Na2CO3 CO When heated at between 200 and 525 C with vanadium pentoxide in a 1 2 molar ratio the above reaction is suppressed yielding instead a sodium vanadium oxibronze with release of carbon dioxide 6 x Na2C2O4 2 V2O5 2 NaxV2O5 2x CO2 with x increasing up to 1 as the temperature increases Sodium oxalate is used to standardize potassium permanganate solutions It is desirable that the temperature of the titration mixture be greater than 60 C to ensure that all the permanganate added reacts quickly The kinetics of the reaction are complex and the manganese II ions Mn2 formed catalyze the further reaction between permanganate and oxalic acid formed in situ by the addition of excess sulfuric acid The final equation is as follows 7 5 Na2C2O4 2 KMnO4 8 H2SO4 K2SO4 5 Na2SO4 2 MnSO4 10 CO2 8 H2OBiological activity editLike several other oxalates sodium oxalate is toxic to humans It can cause burning pain in the mouth throat and stomach bloody vomiting headache muscle cramps cramps and convulsions drop in blood pressure heart failure shock coma and possible death Mean lethal dose by ingestion of oxalates is 10 15 grams kilogram of body weight per MSDS Sodium oxalate like citrates can also be used to remove calcium ions Ca2 from blood plasma It also prevents blood from clotting Note that by removing calcium ions from the blood sodium oxalate can impair brain function and deposit calcium oxalate in the kidneys References edit a b ChemIDplus 62 76 0 ZNCPFRVNHGOPAG UHFFFAOYSA L Disodium oxalate Similar structures search synonyms formulas resource links and other chemical information chem nlm nih gov NIH Retrieved 7 January 2019 a b c d Yoshimori T1 Asano Y Toriumi Y Shiota T 1978 Investigation on the drying and decomposition of sodium oxalate Talanta volume 25 issue 10 pages 603 605 doi 10 1016 0039 9140 78 80158 1 GHS GESTIS 570199 Natroxolate PDF RRUFF Mineral Data Publishing Retrieved 7 January 2019 H W Foote and John E Vance 1933 The system sodium iodate sodium oxalate water American Journal of Science series 5 volume 26 issue 151 pages 16 18 doi 10 2475 ajs s5 26 151 16 D Ballivet Tkatchenko J Galy M Savariault 1994 Thermal decomposition of sodium oxalate in the presence of V2O5 Mechanistic approach of sodium oxibronzes formation Thermochimica Acta volume 232 issue 2 pages 215 223 doi 10 1016 0040 6031 94 80061 8 Mcbride R S 1912 The standardization of potassium permanganate solution by sodium oxalate J Am Chem Soc 34 4 393 416 doi 10 1021 ja02205a009 Retrieved from https en wikipedia org w index php title Sodium oxalate amp oldid 1199038071, wikipedia, wiki, book, books, library,
