ISSN:
1572-9001
Schlagwort(e):
Thermodynamics
;
combustion calorimetry
;
2-bromobenzoic acid
;
3-bromobenzoic acid
;
4-bromobenzoic acid
;
2-iodobenzoic acid
;
3-iodobenzoic acid
;
4-iodobenzoic acid
;
enthalpies of combustion, of formation, of atomization, of intramolecular bonds
;
resonance energy
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract Using our technique of combustion of small amount of a substance, we determined by calorimetry the standard molar enthalpy of formation in the condensed state and atT=298.15 K of the three isomers of bromo and iodobenzoic acids. Associating to these values their standard molar enthalpies of sublimation previously measured, it was possible to determine their standard molar enthalpies of formation in the gaseous state and atT=298.15 K. The experimental values of the thermodynamic properties δf H m o (cr, 298.15 K), δf H m o (cr, 298.15 K), δsub H m o (298.15 K), and δf H m o (g, 298.15 K) are given for the two series. From the experimental value of the standard molar enthalpy of atomization, it was possible to determine an enthalpy value for the Cb-Br and Cb-I bonds. The experimental and theoretical values of the resonance energy of bromo and iodobenzoic acids are compatible. The relative stability of some monosubstituted derivatives of benzoic acid studied in our laboratory is also discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF02275165
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