Densities and Volumetric Properties of Aqueous Solutions of {Water (1) + N-Methylurea (2)} Mixtures at Temperatures of 274.15-333.15 K and at Pressures up to 100 MPa

Densities of the mixture {water (1) + N- methylurea (2)} in the concentration range to mole fraction x(2) = 0.07071 (or to the solution molality concentration m(2) = 4.22335 mol.kg(-1)) at atmospheric pressure in the temperature range from 274.15 to 333.15 K and compression k = Delta V/V-0 at pressures to 100 MPa (10, 25, 50, 75, and 100) in the temperature range from 278.15 to 323.15 K (278.15, 288.15, 288.15, 308.15, 323.15) in the same concentration range were calculated in this study. The apparent molar volumes of N-methylurea V-phi,V-2 and the partial molar volumes of both cornponents (V) over bar (1) and (V) over bar (2) in the mixture, molar isothermal compressibilities K-T,K-m, molar isobaric thermal expansions E-P,E-m, and isochoric coefficients of thermal pressure beta of the mixture were calculated. Moreover, volumetric measures for the infinitely dilute solution of N-methylurea solution were calculated: limiting partial molar volumes (V) over bar (infinity)(2), the limiting partial molar isothermal compressibilities (K) over bar (infinity)(T,2), and the limiting partial molar isobaric thermal expansions (E) over bar (infinity)(P,2). The results obtained are discussed from the point of view of solute-solvent and solute-solute interactions.