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, H E, over the curve shaped for the experimental Cp E data, molecular interactions in the mixtures, isomeric effect of the amines and modeling of Cp E data. © Springer Science+Business Media, LLC 2007.367913922Reimann, R., Heintz, A., Thermodynamic excess properties of alkanol + amine mixtures and application of the ERAS model (1991) J. Solution Chem, 20, pp. 29-37Funke, H., Wetzel, M., Heintz, A., New applications of the ERAS-Model. Thermodynamics of amine + alkane and alcohol + amine mixtures (1989) Pure Appl. Chem, 8, pp. 1429-1439Matteoli, E., Lepori, L., Spanedda, A.: Thermodynamic study of heptane + amine mixtures: I. Excess and solvation enthalpies at 298.15 K. Fluid Phase Equilib. 212, 41-52 (2003)Pina, C.G., Francesconi, A.Z., New applications of the ERAS-model: Excess volumes of binary liquid mixtures of 1-alkanols with acetonitrile (1998) Fluid Phase Equilib, 143, pp. 142-152Zapata, R.B., Villa, A.L., Correa, C.M., Liquid-liquid equilibrium for the water + acetonitrile + limonene system at different temperatures (2005) J. Chem. Eng. Data, 50, pp. 1353-1356Kozak, A., Czaja, M., Chmurzynski, L., Studies on (acid + base) equilibria in substituded (phenol + n-butylamine) systems in acetonitrile (2005) J. Chem. Thermodyn, 37, pp. 810-813Pathak, G., Adyanthaya, S.D., Patil, K.R., Pradhan, S.D., Excess enthalpies and excess volumes of mixing for mixtures of isomeric butyl amines and acetonitrile (1994) Thermochim. Acta, 236, pp. 123-130Torres, R.B., Francesconi, A.Z.: Application of the ERAS-model to binary mixtures of diethylamine and s-butylamine with acetonitrile in the temperature range (288.15-303.15) K. Fluid Phase Equilib. 200, 317-328 (2002)Checoni, R.F., Francesconi, A.Z., Measurement and correlation of excess molar enthalpy at various temperatures - acetonitrile + diethylamine or s-butylamine mixtures (2005) J. Therm. Analysis Calorim, 80, pp. 295-301Checoni, R.F., Francesconi, A.Z., Partial molar enthalpy properties and correlation of excess molar enthalpy data of acetonitrile + diethylamine or s-butylamine mixtures at various temperatures and atmospheric pressure (2006) Thermochim. Acta, 450, pp. 126-131Tamura, K., Excess heat capacities of the mixtures containing methylcyclohexane at 298.15 K (2001) Fluid Phase Equilib, 182, pp. 303-312Nishimoto, M., Tamura, T., Murakami, S., Excess isobaric heat capacity, density and speed of sound of {xCF3CH2OH + (1 - x)CH 3CN} at the temperature 308.15 K (1997) J. Chem. Thermodyn, 29, pp. 15-22Piñeiro, A., Excess volumes and isobaric heat capacities of diisopropyl ether with alkanols at 298.15 K: Application of the symmetrical extended real associated solution model (2004) Fluid Phase Equilib, 216, pp. 245-256Hanks, R.W., Christensen, J.J.: The prediction of multicomponent vapor-liquid equilibria from binary heats of mixing. I. Chem. Symp. Ser. 56, 31-48 (1980)Murty, A.K.S., Zudkevitch, D.: Effect of heat of mixing and vapor-liquid equilibrium on design, performance andeconomics of distillation. I. Chem. Symp. Ser. 56, 51-77 (1980)Lide, D.R., (2005) Handbook of Chemistry and Physics, , CRC Press, Boca RatonNagamachi, M.Y., (2001) Experimental measurements and model to excess properties of aqueous systems with specific interactions, , Ph.D. Thesis, UNICAMP, CampinasOgawa, H., Murakami, S., Excess isobaric heat capacities for water + alkanols mixtures at 298.15 K (1986) Thermochim. Acta, 109, pp. 145-154Saint-Victor, M.E., Patterson, D., The w-shape concentration dependence of CpE and solution non-randomness: Ketones + normal and branched alkanes (1987) Fluid Phase Equilib, 35, pp. 237-252Andreolli-Ball, L., Costas, M., Paquet, P., Patterson, D., Saint-Victor, M.E., Heat capacity and structure in strongly-interacting systems (1989) Pure Appl. Chem, 61 (6), pp. 1075-1084Nishikawa, K., Tamura, K., Murakami, S., Excess thermodynamic properties of (xc-C6H10O + (1 - x)(n-C7H16 or c-C6H120} at T = 298.15 K (1998) J. Chem. Thermodyn, 30, pp. 229-240Nakamura, M., Tamura, K., Murakami, S., Isotope effects on thermodynamic properties: Mixtures of x(D2O or H2O) + (1 - x)(CH 3CN) at 298.15 K (1995) Thermochim. Acta, 253, pp. 127-136Tamura, K., Osaki, A., Murakami, S., Ohji, H., Ogawa, H., Laurent, B., Grolier, J.-P.E., Thermodynamic properties of binary mixtures {an alkoxyethanol + n-octane}. Excess molar enthalpies and excess molar heat capacities at 298.15 K (1999) Fluid Phase Equilib, 156, pp. 137-147Aucouturier, C., Roux-Desgranges, G., Roux, A.H., Excess molar volumes and excess molar heat capacities of (polyethylene glycols + water) at temperatures between T = 278 K and T = 328 K (1999) J. Chem. Thermodyn, 31, pp. 289-300Nan, Z., Liu, B., Tan, Z., Calorimetric investigation of excess molar heat capacities for water + ethylene glycol from T = 273.15 to T = 373.15 K (2002) J. Chem. Thermodyn, 34, pp. 915-926Grolier, J.-P.E., Wilhelm, E., Excess volume and excess heat capacities of water + ethanol at 298.15 K (1981) Fluid Phase Equilib, 6, pp. 283-287Springer, C.S., Meek, D.W., A nuclear magnetic resonance study of diethylamine hydrogen bonding (1966) J. Phys. Chem, 70, pp. 481-186Gepert, M., Zorebski, E.: Leszczynska, A. : Is Flory's model the best tool for studying the thermodynamic properties of any kind of binary mixtures'? A critical study of selected systems of hydrocarbons. Fluid Phase Equilib. 233, 157-169 (2005)Patterson, D., Structure and the thermodynamics of non-electrolyte mixtures (1995) Thermochim. Acta, 267, pp. 15-27Cobos, J.C., An exact quasi-chemical equation for excess heat capacity with W-shaped concentration dependence (1997) Fluid Phase Equilib, 133, pp. 105-127Guggenheim, E.A., (1952) Mixtures, pp. 29-87. , Clarendon Press, OxfordTroncoso, J., Cerdeiriña, C.A., Carballo, E., Romani, L., Quantitative analysis of the W-shaped excess heat capacities of binary liquid mixtures in the light of the local composition concept (2005) Fluid Phase Equilib, 235, pp. 201-210