Oxalic acid

Oxalic acid is an organic compound with the molecular formula C2H2O4.

Formula
C2H2O4
Functional group
Carboxylic acids; Dicarboxylic acids
Molar mass
90.03 g/mol
Also known as
ethanedioic acid, Aktisal, Aquisal, Oxiric acid, Kyselina stavelova, Oxaalzuur

Overview

Oxalic acid is an organic compound with the molecular formula C2H2O4.

Identifiers

Formula
C2H2O4
Functional group
Carboxylic acids; Dicarboxylic acids
Molar mass
90.03 g/mol
Also known as
ethanedioic acid, Aktisal, Aquisal, Oxiric acid, Kyselina stavelova, Oxaalzuur
Chemical identifiers
SMILES
C(=O)(C(=O)O)O
InChI
InChI=1S/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)
PubChem CID
971

Properties

Melting / decomposition
189.5 °C (DECOMPOSES)
Sublimation
Sublimes (NIOSH, 2024)
Density
1.9 g/cm³
Water solubility
Water solubility of 220,000 mg/l at 25 °C

Related compounds

  • Carboxylic acids

    Oxalic acid is an organic compound with the molecular formula C2H2O4.

  • Dicarboxylic acids

    Oxalic acid is an organic compound with the molecular formula C2H2O4.

References

  1. PubChem Compound Summary: Oxalic acid (CID 971)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  2. Hazardous Substances Data Bank (HSDB): Oxalic acid — melting pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/971#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Budavari, S. (ed.). The Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. Rahway, NJ: Merck and Co., Inc., 1989., p. 1093

  3. CAMEO Chemicals: Oxalic acid — boiling pointCAMEO Chemicals

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/971#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.

  4. ILO-WHO International Chemical Safety Cards (ICSCs): Oxalic acid — densityILO-WHO International Chemical Safety Cards (ICSCs)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/971#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.

  5. Hazardous Substances Data Bank (HSDB): Oxalic acid — solubilityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/971#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Yalkowsky SH et al; Arizona Data Base of Water Solubility (1989)