The thermodynamic properties to 700 K of naphthalene and 2,7-dimethylnaphthalene
Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for naphthalene and 2,7-dimethylnaphthalene. Experimental methods included adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, and differential-scanning calorimetry (d.s.c.). The critical temperature and critical density were determined experimentally for each compound and the critical pressures were derived from fitting procedures. Vapor-pressure measurements reported in the literature were compared with the results obtained in this research. Enthalpies of vaporization and sublimation were derived from the experimental measurements and compared with literature results. New self-consistent equations for the variation of sublimation pressure with temperature for naphthalene and 2,7-dimethylnaphthalene were derived. Literature values for entropies and enthalpies of the liquid phases and energies of combustion were combined with the present results to derive entropies, enthalpies, and Gibbs energies of formation for the ideal gases for selected temperatures between 298.15 K and 700 K. The ideal-gas properties for naphthalene were compared with values obtained using statistical mechanics with various fundamental vibrational frequency assignments available in the literature. A scheme to estimate the ideal-gas thermodynamic functions for alkylnaphthalenes was updated. The barrier to methyl-group rotation in 2,7-dimethylnaphthalene was shown to be of the same order of magnitude as that published for toluene. Values for ideal-gas entropies for 2-methylnaphthalene in the temperature range 300 K to 700 K were estimated.
- Research Organization:
- National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC22-83FE60149
- OSTI ID:
- 10181459
- Report Number(s):
- NIPER-678; ON: DE93000160
- Resource Relation:
- Other Information: PBD: Aug 1993
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NAPHTHALENE
THERMODYNAMIC PROPERTIES
SPECIFIC HEAT
CALORIMETRY
CRITICAL TEMPERATURE
DENSITY
VAPOR PRESSURE
VAPORIZATION HEAT
SUBLIMATION HEAT
ENTHALPY
ENTROPY
FREE ENTHALPY
TEMPERATURE RANGE 0273-0400 K
EXPERIMENTAL DATA
023000
400201
PROPERTIES AND COMPOSITION
CHEMICAL AND PHYSICOCHEMICAL PROPERTIES