RT info:eu-repo/semantics/article
T1 Thermodynamics of amide+ketone mixtures. 1. Volumetric, speed of sound and refractive index data for N,N-dimethylformamide+2-alkanone systems at several temperatures
A1 Cobos Huerga, Ana
A1 Hevia de los Mozos, Luis Fernando
A1 González López, Juan Antonio Mariano
A1 García de la Fuente, Isaías Laudelino
A1 Alonso-Tristán, Cristina
K1 Termodinámica
K1 2213 Termodinámica
AB Densities,ρ, speeds of sound, c, and refractive indices, n_D, have been measured for the systems N,N-dimethylformamide (DMF) + propanone, + 2-butanone, or + 2-pentanone in the temperature range from 293.15 to 303.15 K and at 298.15 K for the DMF + 2-heptanone mixture. Due to the high volatility of acetone, the corresponding n_D measurements were developed at 293.15 K and 298.15 K. The direct experimental data were used to determine the excess molar volumes,V_m^E,  and the excess refractive indices, n_D^E, at the working temperatures. Values of the excess functions at 298.15 K, for the speed of sound,c^E, the isentropic compressibility, κ_S^Eand for the excess thermal expansion coefficient, α_p^E, were also calculated. The investigated systems are characterized by strong amide-ketone interactions, which become weaker when the alkanone size is increased. This is supported by negative〖V_m^E〗^values; by the dependence on temperature and pressure of V_m^E, and by positiveP_int^E(excess internal pressure) values. Analysis of the systems in terms of the Rao’s constant indicates that there is no complex formation. In addition, negative V_m^E values also reveal the existence of structural effects, which largely contribute to the excess molar enthalpy, H_m^E. V_m^E and H_m^E values increase with the chain length of the 2-alkanone. It allows conclude that the relative V_m^E variation with the ketone size is closely related to that of the interactional contribution to this excess function. Molar refraction values, R_m, show that dispersive interactions become more relevant for the systems including longer 2-alkanones.
PB Elsevier
SN 0021-9614
YR 2016
FD 2016
LK https://uvadoc.uva.es/handle/10324/69166
UL https://uvadoc.uva.es/handle/10324/69166
LA spa
NO The Journal of Chemical Thermodynamics, 2016, 98, 21-32
DS UVaDOC
RD 27-jul-2024