Thermodynamics Research Center / ThermoML | Thermochimica Acta

Determination of Standard Enthalpy of Vaporization and Thermal Decomposition Reactions from Derivative Thermogravimetric (DTG) Curves

Kolay, S., Mishra, R., Dharwadkar, S. R.
Thermochim. Acta 2011, 512, 1-2, 110-7
ABSTRACT
The paper proposes the use of the derivative thermogravimetric (DTG) curve for the acquisition of equilibrium vapor pressure and dissociation pressure for the materials and derivation of their standard enthalpy of formation from single DTG curve recorded under optimum experimental conditions, such as heating rate and the sweep rate of the carrier gas passed over the sample. The vapor pressure and the standard enthalpy of formation ( ' fHo 298.15 ) of CdI2 and the dissociation pressure and the standard enthalpy of formation of CaCO3 derived from their DTG curves are found to be in good agreement with the best assessed values reported in the literature.
Compounds
# Formula Name
1 CaO calcium monoxide
2 CO2 carbon dioxide
3 CCaO3 calcium carbonate
4 CdI2 cadmium iodide (CdI2)
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 Constraint Phase Method #Points
  • POMD
  • 4
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • TG
  • 7
  • RXND
  • 3
  • 1
  • 2
  • Thermodynamic equilibrium constant
  • Dynamic equilibration
  • 13