Measurements of the molar heat capacities and excess molar heat capacities for acetonitrile plus diethylamine or sec-butylamine mixtures at various temperatures and atmospheric pressure

As a continuation of our studies of the excess functions of binary systems containing acetonitrile (1 - x)-amines (x) mixtures, the molar heat capacity, Cp, and excess molar heat capacity, Cp-E, of acetonitrile + diethylamine or sec-butylamine mixtures have been determined as a function of composition at 288.15, 293.15, 298.15 and 303.15 K at atmospheric pressure using a modified 1455 PARR solution calorimeter. The excess heat capacity data are positive for both systems over the whole composition range. The experimental data on the excess molar heat capacity are discussed in terms of the influence of the magnitude of the experimental excess molar enthalpy, HE, over the curve shaped for the experimental CpE data, molecular interactions in the mixtures, isomeric effect of the amines and modeling of CPE data.36791392

Measurements of the Molar Heat Capacities and Excess Molar Heat Capacities for Water plus Organic Solvents Mixtures at 288.15 K to 303.15 K and Atmospheric Pressure

Experimental molar heat capacity data (Cp(m)) and excess molar heat capacity data (Cp(m)(E)) of binary mixtures containing water + (formamide or N,N-dimethylformamide or dimethylsulfoxide or N,N-dimethylacetamide or 1,4-dioxane) at several compositions, in the temperature range 288.15 K to 303.15 K and atmospheric pressure, have been determined using a modified 1455 PAAR solution calorimeter. The excess heat capacities are positive for aqueous solutions containing 1,4-dioxane, N,N-dimethylformamide or dimethylsulfoxide, negative for solutions containing water + formamide and show a sigmoid behavior for mixtures containing water + N,N-dimethylacetamide, over the whole composition range. The experimental excess molar heat capacities are discussed in terms of the influence of temperature and of the organic solvent type present in the binary aqueous mixtures, as well as in terms of the existing molecular interactions and the organic solvent's molecular size and structure.39225927

Measurements of excess molar enthalpy and excess molar heat capacity of (1-heptanol or 1-octanol)+(diethylamine or s-butylamine) mixtures at 298.15 K and 0.1 MPa

Experimental data of excess molar enthalpy (H (m) (E) ) and excess molar heat capacity (C (pm) (E) ) of binary mixtures containing (1-heptanol or 1-octanol)+(diethylamine or s-butylamine) have been determined as a function of composition at 298.15 K and at 0.1 MPa using a modified 1455 Parr solution calorimeter. The excess molar enthalpy data are negative and show parabolic format over the whole composition range; however, the excess molar heat capacity values, whose curves show a S-shape, are positive in the 0.0 to 0.7 molar fraction range and negative between the molar fraction values 0.7 to 1.0. The applicability of the ERAS-model to correlate the excess molar enthalpy data was tested. The calculated data values are in good agreement with the experimental ones. The experimental behavior of H (m) (E) is interpreted in terms of specific interactions between 1-alkanol and amine molecules.97274775

Experimental Study of the Excess Molar Enthalpy of Ternary Mixtures Containing Water + (1,2-Propanediol, or 1,3-Propanediol, or 1,2-Butanediol, or 1,3-Butanediol, or 1,4-Butanediol, or 2,3-Butanediol) plus Electrolytes at 298.15 K and Atmospheric Pressure

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Excess molar enthalpies (H (m) (E) ) of ternary mixtures containing water+(1,2-propanediol or 1,3-propanediol or 1,2-butanediol or 1,3-butanediol or 1,4-butanediol or 2,3-butanediol)+(sodium bromide, or ammonium bromide, or tetraethyl ammonium bromide, or 1-n-butyl-3-methylimidazolium bromide at 0.1 mola <...dm(-3)) at 298.15 K and atmospheric pressure have been determined as a function of composition using a modified 1455 Parr mixture calorimeter. The H (m) (E) values are negative for all mixtures over the whole composition range. The influence of the electrolyte on the hydrophobic and hydrophilic effects as well as on the behavior of H (m) (E) is discussed.38810551070Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Measurement and correlation of excess molar enthalpy at various temperatures - Acetonitrile plus diethylamine or s-butylamine mixtures

As a continuation of our studies on excess functions of binary systems containing acetonitrile-amines mixtures, in this work excess molar enthalpy (H-m) of acetonitrile+diethylamine or s-butylamine mixtures have been determined as a function of composition at 288.15, 293.15, 298.15 and 303.15 K at atmospheric pressure using a modified 1455 Parr adiabatic calorimeter. The excess enthalpy data are positive for both systems over the whole composition range. ERAS-Model calculations allowing for self-association and cross-association of the components were performed. The results of the calculations and the influence of temperature and isomers chains on the excess enthalpy behavior are discussed.80229530