1,2-Benzenedicarboxylic acid

• Formula: C₈H₆O₄
• Molecular weight: 166.1308
• IUPAC Standard 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) Copy

  
• IUPAC Standard InChIKey: XNGIFLGASWRNHJ-UHFFFAOYSA-N Copy
• CAS Registry Number: 88-99-3
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Phthalic acid; o-Benzenedicarboxylic acid; o-Dicarboxybenzene; Benzene-1,2-dicarboxylic acid; o-Phthalic acid; Acide phtalique; Kyselina ftalova; Sunftal 20; Orthophthalic acid
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Condensed phase thermochemistry data
  • Phase change data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • IR Spectrum
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Condensed phase thermochemistry data

Go To: Top, Phase change data, Mass spectrum (electron ionization), References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of solid

Phase change data

Go To: Top, Condensed phase thermochemistry data, Mass spectrum (electron ionization), References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Enthalpy of fusion

Mass spectrum (electron ionization)

Go To: Top, Condensed phase thermochemistry data, Phase change data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

References

Go To: Top, Condensed phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Schwabe and Wagner, 1961
Schwabe, K.; Wagner, W., Verbrennungs- und bildungswarmen der drei isomeren phthalsauren, Z. Electrochem., 1961, 65, 812-815. [all data]

Parks, Mosley, et al., 1950
Parks, G.S.; Mosley, J.R.; Peterson, P.V., Jr., Heats of combustion and formation of some organic compounds containing oxygen, J. Chem. Phys., 1950, 18, 152. [all data]

Richardson and Parks, 1939
Richardson, J.W.; Parks, G.S., Thermal data on organic compounds. XIX. Modern combustion data for some non-volatile compounds containing carbon, hydrogen and oxygen, J. Am. Chem. Soc., 1939, 61, 3543-3546. [all data]

Verkade, 1926
Verkade, P.E., Verbrandingswarmten van plaatsings-isomere benzol-derivaten en de theorie der geinduceerde alterneeren de polatiteit, Verslag Akad. Wetenschappen Amsterdam, 1926, 35, 492-504. [all data]

Parks, Todd, et al., 1936
Parks, G.S.; Todd, S.S.; Moore, W.A., Thermal data on organic compounds. XVI. Some heat capacity, entropy and free energy data for typical benzene derivatives and heterocyclic compounds, J. Am. Chem. Soc., 1936, 58, 398-401. [all data]

Satoh and Sogabe, 1941
Satoh, S.; Sogabe, T., The heat capacities of some organic compounds containing nitrogen and the atomic heat of nitrogen. (4), Sci., Pap. Inst. Phys. Chem. Res. (Tokyo), 1941, 38, 246-251. [all data]

Satoh and Sogabe, 1939
Satoh, S.; Sogabe, T., The specific heats of some solid aromatic acids and their ammonium salts and the atomic heat of nitrogen, Sci. Pap. Inst. Phys. Chem. Res. (Tokyo), 1939, 36, 449-457. [all data]

Parks, Todd, et al., 1936, 2
Parks, G.S.; Todd, S.S.; Shomate, C.H., Thermal data on organic compounds. XVII. Some heat capacity, entropy and free energy data for five higher olefins, J. Am. Chem. Soc., 1936, 58, 2505. [all data]

Sabbah and Perez, 1999
Sabbah, Raphaël; Perez, Laurence, Étude thermodynamique des acides phtalique, isophtalique et téréphtalique, Revue canadienne de chimie, 1999, 77, 9, 1508-1513, https://doi.org/10.1139/cjc-77-9-1508 . [all data]

Notes

Go To: Top, Condensed phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  S°solid,1 bar	Entropy of solid at standard conditions (1 bar)
  Tfus	Fusion (melting) point
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔsubH°	Enthalpy of sublimation at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.