Thermochemistry of 9-hydroxy-1,4-anthraquinone and 9-methoxy-1,4-anthraquinone

• Published in: The Journal of chemical thermodynamics Vol. 34; no. 7; pp. 1117 - 1126
• Main Authors: Jiménez, P., Roux, M.V., Dávalos, J.Z., Molina, M.T.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2002; Elsevier
• Subjects: 9-hydroxy-1,4-anthraquinone; 9-methoxy-1,4-anthraquinone; Chemical thermodynamics; Chemistry; Elements, mineral and organic compounds; energy of combustion; enthalpy of combustion; enthalpy of formation; enthalpy of sublimation; Exact sciences and technology; General and physical chemistry; heat capacity; Knudsen effusion; Thermodynamic properties; vapour pressures; 9-hydroxy-1,4-anthraquinone; Knudsen effusion; energy of combustion; enthalpy of combustion; enthalpy of formation; enthalpy of sublimation; 9-methoxy-1,4-anthraquinone; vapour pressures; heat capacity; Heat of combustion; Vapor pressure; Heat of sublimation; Enthalpy; Quinone; Phenols; Experimental study; Thermodynamic properties; Anthracene derivatives
• ISSN: 0021-9614; 1096-3626
• DOI: 10.1006/jcht.2002.0986

The standard molar energy of combustion of 9-hydroxy-1,4-anthraquinone and 9-methoxy-1,4-anthraquinone were determined with a static-bomb calorimeter. The vapour pressures of the compounds were measured at temperatures between (376.61 and 394.56) K for 9-hydroxy-1,4-anthraquinone and at temperatures between (363.26 and 386.62) K for 9-methoxy-1,4-anthraquinone, by the Knudsen-effusion technique. The heat capacity of these two quinones were determined fromT= 268.15 K to temperatures near melting with differential scanning calorimetry. From the experimental results, the standard molar enthalpies of combustion, sublimation and formation in the crystalline and gaseous state at T= 298.15 K were derived for 9-hydroxy-1,4-anthraquinone and 9-methoxy-1,4-anthraquinone.