TY - JOUR
T1 - Thermodynamics of fenoxycarb in solution
AU - Kuhs, Manuel
AU - Svärd, Michael
AU - Rasmuson, Åke C.
PY - 2013
Y1 - 2013
N2 - 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 1H 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.
AB - 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 1H 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.
KW - Activity
KW - Activity coefficient
KW - Heat capacity
KW - Hoff enthalpy
KW - Ideal solution
KW - Solubility
KW - Van't
UR - http://www.scopus.com/inward/record.url?scp=84880380345&partnerID=8YFLogxK
U2 - 10.1016/j.jct.2013.06.007
DO - 10.1016/j.jct.2013.06.007
M3 - Article
AN - SCOPUS:84880380345
SN - 0021-9614
VL - 66
SP - 50
EP - 58
JO - Journal of Chemical Thermodynamics
JF - Journal of Chemical Thermodynamics
ER -