| Popis: |
The (p, ρ, T, x) properties for {xNH3 + (1 − x)H2O} with x = (0.1048, 0.2046, 0.3807, 0.5565, 0.7008, 0.8010, 0.9102, and 1.0000) in the compressed liquid phase were measured by means of a metal-bellows variable volumometer at temperatures of (450 and 500) K and pressures from (10 to 200) MPa. The volume fraction purities of the ammonia used in the measurements were 0.99999. The water employed was deionised, distilled, and degassed to 3.0 ≅ 10−4 Pa by freeze–thaw cycling with liquid nitrogen before use. In order to carry out these measurements at higher ranges of temperature (above T = 450 K) and pressure (up to p = 200 MPa), we have implemented several reconstructions to the apparatus, including the replacement of the sample cell containing the metal-bellows, and the development of a thermostatted air bath, in which the temperature of the air and sample cell can be raised up to 600 K. The expanded uncertainties (k = 2) in temperature, pressure, density, and composition measurements have been estimated to be less than 5 mK; 1.3 × 10−2%; 0.48%; and 8.2 × 10−4, respectively. Comparisons of the available equations of state (EoS) with the present measurements are reported. On the basis of the present results, moreover, the excess molar volume v m E of the mixtures was calculated and illustrated as a function of temperature and pressure. |
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