Peer-Reviewed Journal Details
Mandatory Fields
Kuhs, M; Svard, M; Rasmuson, AC
2013
January
Journal Of Chemical Thermodynamics
Thermodynamics of fenoxycarb in solution
Published
()
Optional Fields
Solubility Activity Activity coefficient Van't Hoff enthalpy Ideal solution Heat capacity MELTING TEMPERATURES ORGANIC-SOLVENTS SOLUBILITY ENTHALPIES TRANSITION PIRACETAM FUSION RANGE HEAT ACID
66
50
58
The solubility of fenoxycarb has been determined between 278 and 318 K in several organic solvents. The solid phase at equilibrium and some indication of polymorphism has been properly examined by powder XRD, DSC, Raman and ATR-FTIR spectroscopy, solution H-1 NMR and SEM. Using literature data the activity of the solid phase within a Raoult's law definition has been calculated, based on which solution activity coefficients have been estimated. In ethyl acetate, the van't Hoff enthalpy of solution is constant over the temperature range and equals the melting enthalpy. However, it is shown that the solution is slightly non-ideal with the heat capacity difference term compensating for the activity coefficient term. In toluene, the van't Hoff enthalpy of solution is constant as well but clearly higher than the melting enthalpy. In methanol, ethanol and isopropanol, van Hoff curves are strongly non-linear, the slope however clearly approaching the melting enthalpy at higher temperatures. In all solvents, positive deviations from Raoult's law are prevailing. The activity coefficients follow a decreasing order of isopropanol > ethanol > methanol > toluene > ethyl acetate, and in all solvents decrease monotonically with increasing temperature. The highest activity coefficient is about 18 corresponding to about 2.5 kJ/mol of deviation from ideality. (c) 2013 Elsevier Ltd. All rights reserved.
10.1016/j.jct.2013.06.007
Grant Details