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

Densities of the mixture {water (1) + <i>N</i>- methylurea (2)} in the concentration range to mole fraction <i>x</i>₂ = 0.07071 (or to the solution molality concentration <i>m</i>₂ = 4.22335 mol·kg^–1) at atmospheric pressure in the temperature range from 274.15 to 333.15 K and compression <i>k</i> = Δ<i>V</i>/<i>V</i>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 <i>N</i>-methylurea <i>V</i>_ϕ,2 and the partial molar volumes of both components <i>V̅</i>₁ and <i>V̅</i>₂ in the mixture, molar isothermal compressibilities <i>K</i>_<i>T,m</i>, molar isobaric thermal expansions <i>E</i>_<i>P,m</i>, and isochoric coefficients of thermal pressure β of the mixture were calculated. Moreover, volumetric measures for the infinitely dilute solution of <i>N</i>-methylurea solution were calculated: limiting partial molar volumes <i>V̅</i>₂^∞, the limiting partial molar isothermal compressibilities <i>K̅</i>_<i>T</i>,2^∞, and the limiting partial molar isobaric thermal expansions <i>E̅</i>_<i>P</i>,2^∞. The results obtained are discussed from the point of view of solute–solvent and solute–solute interactions