- Formula: C4H2O4
- Molecular weight: 114.0563
- IUPAC Standard InChI:
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- IUPAC Standard InChIKey: PWEBUXCTKOWPCW-UHFFFAOYSA-N
- CAS Registry Number: 2892-51-5
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
- Other names: Squaric acid; Cyclobutenedione, dihydroxy-; Quadratic acid; 1,2-Dihydroxycyclobutene-3,4-dione; 1,2-Diketo-3,4-dihydroxycyclobutene; 3,4-Dihydroxy-3-cyclobutene-1,2-dione; 1,2-Dihydroxy cyclobutenedione; 1,2-Dihydroxy-3,4-cyclobutenedione; Cyclobutene-1,2-dione, 3,4-dihydroxy-; 3,4-Dihydroxy-cyclobutene-1,2-dione; NSC 125692
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Condensed phase thermochemistry data
Go To: Top, References, Notes
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
|fH°solid||-598.2 ± 0.4||kJ/mol||Ccb||Sellers, 1971||ALS|
|cH°solid||-1261.67 ± 0.33||kJ/mol||Ccb||Sellers, 1971||Corresponding «DELTA»fHºsolid = -598.20 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS|
Constant pressure heat capacity of solid
|Cp,solid (J/mol*K)||Temperature (K)||Reference||Comment|
|121.6||315.||DeWit, Offringa, et al., 1983||T = 300 to 450 K.; DH|
|121.||300.||Barth, Helwig, et al., 1979||crystaline, II phase; T = 300 to 420 K. Data graphically only.; DH|
Go To: Top, Condensed phase thermochemistry data, Notes
Sellers, P., Enthalpies of formation of squaric acid and the corresponding diethyl ether, Acta Chem. Scand., 1971, 25, 2194-2198. [all data]
DeWit, Offringa, et al., 1983
DeWit, H.G.M.; Offringa, J.C.A.; De Kruif, C.G.; Van Miltenburg, J.C., Thermodynamic properties of molecular organic crystals containing nitrogen, oxygen and sulfur. III. Molar heat capacities measured by differential scanning calorimetry, Thermochim. Acta, 1983, 65, 43-51. [all data]
Barth, Helwig, et al., 1979
Barth, E.; Helwig, J.; Maier, H.D.; Mser, H.E.; Petersson, J., Specific heat of the two dimensional antiferroelectric squaric acid, Z. Phys., 1979, B34, 393-397. [all data]
Go To: Top, Condensed phase thermochemistry data, References
- Symbols used in this document:
Cp,solid Constant pressure heat capacity of solid cH°solid Enthalpy of combustion of solid at standard conditions fH°solid Enthalpy of formation of solid at standard conditions
- Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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