Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Low-temperature heat capacity and standard molar enthalpy of formation of crystalline 2-pyridinealdoxime (C6H6N2O)

Shi, Q.[Quan], Tan, Z.-C.[Zhi-Cheng], Tong, B.[Bo], Di, [You-Ying], Zhang, Z.-H.[Zhi-Heng], Zeng, J.-L.[Ju-Lan], Sun, L.-X.[Li-Xian], Li, Y.-S.[Yan-Sheng]
J. Chem. Thermodyn. 2007, 39, 5, 817-821
ABSTRACT
The thermodynamic properties of 2-pyridinealdoxime were investigated through the thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). Low-temperature heat capacity Cp,m of 2-pyridinealdoxime (C6H6N2O; CAS 873-69-8) was measured in the temperature range from (80 to 373) K with a high precision automated adiabatic calorimeter. No phase transition or thermal anomaly was observed in this range. The thermodynamic functions [HT H298.15] and [ST S298.15] were calculated in the range from (80 to 375) K. The constant-volume energy and standard molar enthalpy of combustion have been determined, DcU (C6H6N2O, cr)1/4 DcH m (C6H6N2O, cr) = (3297.11 +- 1.53) kJ Ae mol 1 (based on Dn being zero in reaction of the combustion), by means of a precision oxygen- bomb combustion calorimeter at T = (298.15 +- 0.001) K. The standard molar enthalpy of formation has been derived, DfH m (C6H6N2O, cr) = (78.56 +- 2.43) kJ Ae mol 1, from the standard molar enthalpy of combustion in combination with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.
Compounds
# Formula Name
1 CO2 carbon dioxide
2 N2 nitrogen
3 H2O water
4 O2 oxygen
5 C6H6N2O 2-pyridinealdoxime
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
  • 5
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DSC
  • 1
  • POMD
  • 5
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 5
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal
  • Temperature, K; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • VADIAC:UFactor:4
  • 101
  • RXND
  • 5
  • 1
  • 2
  • 3
  • 4
  • Molar internal energy of reaction at constant volume, kJ/mol
  • Static bomb calorimetry
  • 1