Molecule structure of Ethanedioic acid (CAS NO.97993-78-7):

IUPAC Name: Oxalic acid 
Molecular Weight: 90.03488 g/mol
Molecular Formula: C₂H₂O₄ 
Density: 0.99 g/mL at 25 °C
Melting Point: 189.5 °C (dec.)(lit.)
Boiling Point: 365.1 °C at 760 mmHg 
Flash Point: 101-157 °C
Index of Refraction: 1.48
Molar Refractivity: 14.44 cm³
Molar Volume: 50.8 cm³
Surface Tension: 87.3 dyne/cm 
Enthalpy of Vaporization: 67.15 kJ/mol
Vapour Pressure: 2.51E-06 mmHg at 25 °C 
Water Solubility: 90 g/L (20 °C)
Sublimation: 101-157 °C 
Stability: stable, but moisture sensitive. Incompatible with metals
XLogP3-AA: -0.3
H-Bond Donor: 2
H-Bond Acceptor: 4
Rotatable Bond Count: 1
Exact Mass: 89.995309
MonoIsotopic Mass: 89.995309
Topological Polar Surface Area: 74.6
Heavy Atom Count: 6
Canonical SMILES: C(=O)(C(=O)O)O
InChI: InChI=1S/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)
InChIKey: MUBZPKHOEPUJKR-UHFFFAOYSA-N
EINECS: 205-634-3
Product Categories: Intermediates;Water Ttreatment Chemicals;Eluent concentrates for ICAnalytical Standards;Alphabetic;Chromatography/CE Reagents;Ion Chromatography;O;C1 to C5;Carbonyl Compounds;Carboxylic Acids;Acid SolutionsTitration;Complexometric Solutions (IDRANAL);Complexometric Titration (IDRANAL);Analytical Reagents for General Use;O-P, Puriss p.a.;Puriss p.a.;Acid Concentrates;Concentrates (e.g. FIXANAL);Acid Solutions;Titration;Volumetric Solutions

 Ethanedioic acid is mainly used in cleaning or bleaching. Most Ethanedioic acid is used as a cleaning agent, especially for the removal of rust or removal of iron from minerals specimens. About 25% of produced Ethanedioic acid is used as a mordant in dyeing processes. It is used in bleaches, especially for pulpwood. Ethanedioic acid is also an important reagent in lanthanide chemistry. It is used in the restoration of old wood.

 Ethanedioic acid is mainly made by the oxidation of carbohydrates or glucose using nitric acid or air in the presence of vanadium pentoxide. A variety of precursors can be used including glycolic acid and ethylene glycol. A newer method entails oxidative carbonylation of alcohols to give the diesters of oxalic acid:
4 ROH + 4 CO + O₂ → 2 (CO₂R)₂ + 2 H₂O
These diesters are subsequently hydrolyzed to Ethanedioic acid.

Hazard Codes: Xn
Risk Statements: 21/22-63-34 
R21/22:Harmful in contact with skin and if swallowed. 
R63:Possible risk of harm to the unborn child. 
R34:Causes burns.
Safety Statements: 24/25-23-36/37/39-27-26 
S24/25:Avoid contact with skin and eyes. 
S23:Do not breathe vapour. 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection. 
S27:Take off immediately all contaminated clothing. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
RIDADR: UN 3261 8/PG 3
WGK Germany: 1
RTECS: RO2450000
HazardClass: 8
PackingGroup: III

 Ethanedioic acid (CAS NO.97993-78-7) is also named as 4-02-00-01819 (Beilstein Handbook Reference) ; AI3-26463 ; Acide oxalique ; Acide oxalique [French] ; Acido ossalico ; Acido ossalico [Italian] ; Acidum oxalicum ; Aktisal ; Aquisal ; BRN 0385686 ; CCRIS 1454 ; Caswell No. 625 ; EPA Pesticide Chemical Code 009601 ; HSDB 1100 ; Kyselina stavelova ; Kyselina stavelova [Czech] ; NCI-C55209 ; NSC 62774 ; Oxaalzuur ; Oxaalzuur [Dutch] ; Oxalate ; Oxalic acid ; Oxalsaeure ; Oxalsaeure [German] ; Oxiric acid ; UNII-9E7R5L6H31 . Ethanedioic acid (CAS NO.97993-78-7) is white crystalline powder. It can sinks and mixes with water. Ethanedioic acid is hygroscopic and sensitive to heat. The heating of mixtures of Oxalic acid and urea has lead to explosions. This is due to the rapid generation of the gases, CO₂, CO, and NH₃. Ethanedioic acid may react violently with furfuryl alcohol, silver, sodium, perchlorate, sodium hypochlorite, strong oxidizers, sodium chlorite, acid chlorides, metals and alkali metals. Ethanedioic acid and urea react at high temperatures to produce toxic and flammable ammonia and carbon monoxide gasses, and inert CO₂ gas. As dust or as a solution, it can cause severe burns of eyes, skin, or mucous membranes. Ingestion of 5 grams has caused death with symptoms of nausea, shock, collapse, and convulsions coming on rapidly. Repeated or prolonged skin exposure can cause dermatitis and slow-healing ulcers.