Volumetric Properties of Binary Liquid Mixtures of Water with N-Methylpyrrolidone at (278.15-323.15) K and up to 70 MPa

In the present paper, the density of the water-N-methylpyrrolidonemixture was measured over the entire concentration range of the liquid state of themixture in the range of 0.1 to 70 MPa atfive different temperatures from 278.15 to323.15 K. The data obtained were used to calculate the excess molar volumes andexcess partial molar volumes of water andN-methylpyrrolidone. Limiting values ofpartial molar volumes and excess partial molar volumes ofN-methylpyrrolidone weredetermined at selected temperatures and pressures. The volume characteristics ofaqueous solutions of 2-pyrrolidone andN-methylpyrrolidone were compared. Changesin the volumetric properties of solutions at various state parameters were considered inrelation to their structural features.