Thermodynamics Research Center / ThermoML | Thermochimica Acta

Thermodynamic properties of potassium nitrate-magnesium nitrate compound [2KNO3.Mg(NO3)2]

Reddy, R. G.[Ramana G.], Wang, T.[Tao], Mantha, D.[Divakar]
Thermochim. Acta 2012, 531, 6-11
ABSTRACT
The Mg(NO3)2-KNO3 binary system phase diagram has a congruent melting compound, 2KNO3.Mg(NO3)2 (MgKN). The thermodynamic properties for this compound are not available in the literature. In this study, the nitrate compound was synthesized and the melting point and heat capacity were determined using Differential Scanning Calorimetry (DSC). Two endothermic peaks were observed at 404.8 K and 468.85 K corresponding to solid state transition and melting of the compound with the enthalpies of transitions as 2.51 kJ/mol and 19.20 kJ/mol respectively. The heat capacity data as function of temperature are fit to polynomial function and thermodynamic properties like enthalpy, entropy and Gibbs energies of the compound as function of temperature are subsequently reduced.
Compounds
# Formula Name
1 K2MgN4O12 bis-potassium magnesium nitrate
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
  • 1
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • Triple point temperature, K ; Crystal 1
  • Crystal 1
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Air at 1 atmosphere
  • DSC
  • 1
  • POMD
  • 1
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal 1
  • Crystal 1
  • Liquid
  • Air at 1 atmosphere
  • DSC
  • 1
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 2
  • Temperature, K; Crystal 2
  • Pressure, kPa; Crystal 2
  • Crystal 2
  • Small sample (50 mg) DSC
  • 128
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 1
  • Temperature, K; Crystal 1
  • Pressure, kPa; Crystal 1
  • Crystal 1
  • Small sample (50 mg) DSC
  • 74
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Small sample (50 mg) DSC
  • 186