Thermodynamics Research Center, ThermoML : Journal of Chemical Thermodynamics

Thermodynamic study on levulinic acid in NaCl, (C2H5)4NI and mixed MgCl2/NaCl and CaCl2/NaCl aqueous solutions at T = 298.15 K

Arena, G.[Giuseppe], Bretti, C.[Clemente], Grasso, G. I.[Giuseppa Ida], Lando, G.[Gabriele], Sammartano, S.[Silvio], Sgarlata, C.[Carmelo]
J. Chem. Thermodyn. 2019, 139, 105870
ABSTRACT
Some thermodynamic properties of levulinc acid (LA) were studied under different experimental conditions. The partition coefficient between 2-methyl-1-propanol/pure water (or NaCl aqueous solutions up to I = 1.00 mol dm 3) was measured at T = 298.15 K by means of potentiometric titrations. The protonation constant of levulinic acid was also determined potentiometrically at different ionic strengths in NaCl(aq), (C2H5)4NI(aq) as well as in mixed MgCl2/NaCl and CaCl2/NaCl aqueous solutions. The protonation enthalpy was determined by calorimetric titrations in the same conditions of temperature and ionic strength. The linear fitting of the distribution ratio (log KD) determined at different salt concentrations vs. the salt concentration allowed for the determination of the distribution coefficient at infinite dilution (log K0 D0 = 0.14 +- 0.02), the Setschenow (km = 0.35 +- 0.03) and the activity coefficient of the neutral species (log cHL = km msalt). The activity coefficient of the charged L species was also computed by means of the Specific Interaction Theory (SIT) approach by keeping constant the value of the activity coefficient for the neutral HL species. The medium effect on the protonation constant was also studied using the weak interaction model, namely by comparing the protonation constants obtained in NaCl(aq), (C2H5)4NI(aq) as well as in mixed aqueous MgCl2/NaCl and CaCl2/NaCl mixtures by considering the formation of a NaL(aq), CaL+ (aq), and MgL+ (aq) species.
Compounds
# Formula Name
1 C5H8O3 4-oxopentanoic acid
2 C4H10O 2-methyl-1-propanol
3 H2O water
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
  • 2
  • 3
  • Amount concentration (molarity), mol/dm3 - 1 ; Liquid - 3
  • Amount concentration (molarity), mol/dm3 - 1; Liquid - 2
  • Pressure, kPa; Liquid - 3
  • Temperature, K; Liquid - 3
  • Liquid - 3
  • Liquid - 2
  • potentiometric titration
  • 2