Abstract. The saturated vapor pressure of ethacrylic acid solutions in acetonitrile and acetic acid was measured by a static tensimetric method in the temperature range of 295-355 K. The composition of the equilibrium phases as well as the activity coefficients were received from the experimental measurements of the temperature-dependent saturated vapor pressure. We then used the temperature and concentration dependent activity coefficients to calculate the excess thermodynamic functions of the solutions mixing (H E , G E , S E ).

1 The fusion temperature of 2-cyano-3-[5-(phenyl)-2-furyl]-2-propenamide and 2-cyano-3-[5-(4-methylphenyl)-2-furyl]-2-propenamide and their temperature dependence of dissolution in acetonitrile, benzene, dimethylketone, ethyl acetate and 2-propanol have been determined. According to the temperature dependence the differential enthalpies and entropies of the solution were calculated. Taking into account the entropies of fusion the entropies and enthalpies of mixing were calculated at 298 K. The effect of intermolecular interaction in the investigated solutions on their solubility and enthalpies of mixing has been analyzed.

Using a calorimetric method enthalpies of mixing of the binary systems of methylmethacrylate with acetonitryle, hexane, benzene, 1,2-diclorethane, and acetic acid at 293 K and atmospheric pressure have been measured. The concentration dependences of enthalpies of mixing were correlated by polynomials.

Abstract. The enthalpy of mixing for the binary systems of the laurylmethacrylate with hexane, benzene, 1,2-diclorethane and acetic acid have been measured as a function of their concentration, the temperature of 293 K and at the atmospheric pressure, by the calorimetric methods. The concentration dependences of the enthalpies of mixing were correlated by polynomials. For the system acetic acid-laurylmethacrylate the enthalpies of mixing were positive for all concentrations, while for other systems the enthalpies of mixing takes were positive only when the solvent concentration was greater than 25 mol %.

Densities and excess volumes of the binary systems of butyl methacrylate with acetonitrile; acetic acid, benzene, 1,2-dichlorethane, and hexane have been measured as a function of composition at 293 K and atmospheric pressure by pycnometric method. The measured excess volumes were correlated by polynomials. The partial molar volumes were calculated by experimental data.