Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Thermodynamics of proton dissociation from aqueous bicarbonate: apparent molar volumes and apparent molar heat capacities of potassium carbonate and potassium bicarbonate at T=(278.15 to 393.15) K and at the pressure 0.35 MPa

Sorenson, E. C., Woolley, E. M.[Earl M.]
J. Chem. Thermodyn. 2004, 36, 4, 289-298
ABSTRACT
We have determined the apparent molar volumes V and apparent molar heat capacities Cp, of aqueous potassium carbonate and potassium bicarbonate solutions in the ranges (0.014m/(mol ? kg-1)0.51) and (278.15T/K393.15) at the pressure p=0.35 MPa. Corrections for speciation due to hydrolysis and disproportionation in solution were applied using Young's rule, and semi-empirical equations representing (V,m,T) and (Cp,,m,T) for the species {2K+, CO32-(aq)} and {K+, HCO3-(aq)} were fitted to the experimental results. We have used these equations to estimate the change in volume rVm, change in heat capacity rCp,m, enthalpy change rHm, entropy change rSm, and equilibrium molality quotient pQ for the second proton dissociation reaction from aqueous carbonic acid.
Compounds
# Formula Name
1 H2O water
2 CK2O3 potassium carbonate
3 CHKO3 potassium bicarbonate
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
  • 2
  • 1
  • Apparent molar heat capacity, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Differential flow calorimetry
  • 168
  • POMD
  • 2
  • 1
  • Apparent molar volume, m3/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Calculated with densities of this investigation
  • 77
  • POMD
  • 3
  • 1
  • Apparent molar heat capacity, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 3; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Differential flow calorimetry
  • 168
  • POMD
  • 3
  • 1
  • Apparent molar volume, m3/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 3; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Calculated with densities of this investigation
  • 77