Phthalic acid

Phthalic acid is an organic compound with the molecular formula C8H6O4.

Formula
C8H6O4
Functional group
Carboxylic acids; Dicarboxylic acids
Molar mass
166.13 g/mol
Also known as
1,2-benzenedicarboxylic acid, o-phthalic acid, benzene-1,2-dicarboxylic acid, o-dicarboxybenzene, o-benzenedicarboxylic acid, Acide phtalique

Overview

Phthalic acid is an organic compound with the molecular formula C8H6O4.

Identifiers

Formula
C8H6O4
Functional group
Carboxylic acids; Dicarboxylic acids
Molar mass
166.13 g/mol
Also known as
1,2-benzenedicarboxylic acid, o-phthalic acid, benzene-1,2-dicarboxylic acid, o-dicarboxybenzene, o-benzenedicarboxylic acid, Acide phtalique
Chemical identifiers
SMILES
C1=CC=C(C(=C1)C(=O)O)C(=O)O
InChI
InChI=1S/C8H6O4/c9-7(10)5-3-1-2-4-6(5)8(11)12/h1-4H,(H,9,10)(H,11,12)
PubChem CID
1017

Properties

Melting / decomposition
Decomposes at 230 °C
Boiling / decomposition
Decomposes
Density
1.593 g/cu cm at 15 °C
Water solubility
In water, 6,965 mg/L at 25 °C

Related compounds

  • Carboxylic acids

    Phthalic acid is an organic compound with the molecular formula C8H6O4.

  • Dicarboxylic acids

    Phthalic acid is an organic compound with the molecular formula C8H6O4.

References

  1. PubChem Compound Summary: Phthalic acid (CID 1017)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): Phthalic acid — melting pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/1017#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Lide, D.R. CRC Handbook of Chemistry and Physics 86TH Edition 2005-2006. CRC Press, Taylor & Francis, Boca Raton, FL 2005, p. 3-434

  3. Hazardous Substances Data Bank (HSDB): Phthalic acid — boiling pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/1017#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V1: 797

  4. Hazardous Substances Data Bank (HSDB): Phthalic acid — densityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/1017#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Gerhartz, W. (exec ed.). Ullmann's Encyclopedia of Industrial Chemistry. 5th ed.Vol A1: Deerfield Beach, FL: VCH Publishers, 1985 to Present., p. VA20: 182 (1992)

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

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/1017#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Yalkowsky, S.H., He, Yan., Handbook of Aqueous Solubility Data: An Extensive Compilation of Aqueous Solubility Data for Organic Compounds Extracted from the AQUASOL dATAbASE. CRC Press LLC, Boca Raton, FL. 2003., p. 456