ABSTRACT

In this work, we report the molar enthalpies of formation of ethyl 2-, 3-, and 4-hydroxybenzoates in gas-phase at T = 298.15 K, derived from experimental techniques such as static-bomb combustion calorimetry, differential scanning calorimetry, and thermogravimetric analysis. We calculated as well the enthalpies of formation (of the same compound set) in gas-phase through the Gaussian G4 composite method, and a Boltzmann averaging procedure weighted with the Gibbs free energy. Finally, we discuss and compare experimental and theoretical results.

Compounds

#	Formula	Name
1	CO2	carbon dioxide
2	H2O	water
3	O2	oxygen
4	C9H10O3	ethyl 2-hydroxybenzoate
5	C9H10O3	ethyl 3-hydroxybenzoate
6	C9H10O3	ethyl 4-hydroxybenzoate
7	C4H6O4	butanedioic acid

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Phase	Method	#Points
POMD	4	Molar enthalpy of vaporization or sublimation, kJ/mol ; Liquid	Temperature, K; Liquid	Liquid Gas	Derived by Second law	1
POMD	4	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	4	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	4	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	Small sample (50 mg) DSC	1
POMD	5	Molar enthalpy of vaporization or sublimation, kJ/mol ; Liquid	Temperature, K; Liquid	Liquid Gas	Derived by Second law	1
POMD	5	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	5	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	5	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Pressure, kPa; Crystal Temperature, K; Crystal	Crystal	Small sample (50 mg) DSC	1
POMD	6	Molar enthalpy of vaporization or sublimation, kJ/mol ; Liquid	Temperature, K; Liquid	Liquid Gas	Derived by Second law	1
POMD	6	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	6	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	6	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Pressure, kPa; Crystal Temperature, K; Crystal	Crystal	Small sample (50 mg) DSC	1
RXND	7 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	4 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	5 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	6 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Gas-phase enthalpies of formation of ethyl hydroxybenzoates: An experimental and theoretical approach

Ledo, J. Manuel, Flores, Henoc, Hernandez-Perez, Julio M., Ramos, Fernando, Camarillo, E. Adriana, Solano-Altamirano, J.M.

ABSTRACT