The Densities of Certain Dilute Aqueous Solutions by a New and Precise Method.

The enthalpy of dilution and thermodynamics of Na2CO3(aq) and NaHCO3(aq) fromT= 298 K toT= 523.15 K and pressure of 40 MPa

“…Values of u 6 and u 7 for equation (15) were obtained by fitting the apparent molar volume and isothermal compressibility V φ and κ T,φ to equations for effective quantities V e φ and κ e T,φ that are similar to equations (9) (14) and (15) (14) and (15) density data for Na 2 CO 3 (aq) and NaHCO 3 (aq) reported at temperatures and pressures at or near T = 298.15 K and p = 0.1 MPa by Hershey et al, (4) Perron et al, (5) and Lamb and Lee, (6) and we have fit these V φ values to the equations for V e φ to obtain the values of u 6 given in table 4. There are systematic deviations of V φ values for Na 2 CO 3 (aq) from the equation for V e φ at low molalities; (5) however, these deviations are inconsequential for our purpose of determining the value of u 6 for use in equation (15).…”

“…(2)(3)(4)(5)(6) We have fit values of these thermodynamic quantities as functions of temperature (T /K), pressure ( p/MPa), and water density (ρ w /g · cm −3 ) to equation (13), (10) to (14) with the parameters from tables 3 and 5.…”

“…The pressure dependence of these parameters is also estimated from an analysis of the densities of Na 2 CO 3 (aq) and NaHCO 3 (aq) reported by Hershey et al, (4) Perron et al, (5) and Lamb and Lee, (6) along with analysis of the isothermal compressibility results summarized by Hershey et al (4) We use our results to provide representations of free energies (species distribution, activity coefficients, osmotic coefficients) at temperatures up to T = 523 K, at pressures up to p = 40 MPa, and at molalities that range to near solid saturation. From this analysis, the excess thermodynamic properties of hypothetical unhydrolyzed, nonreacting NaHCO 3 (aq) and Na 2 CO 3 (aq) can be calculated.…”

Density, Apparent and Partial Molar Volumes, and Viscosity of Aqueous Na2CO3Solutions at High Temperatures and High Pressures

“…A literature survey revealed that the number of measurements [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] reported for the density of Na 2 CO 3 (aq) cover very limited ranges of temperature (up to 383 K) and pressure (up to 30 MPa). Shilovskaya and Lenkova [30] measured the density of Na 2 CO 3 (aq) in the temperature range from 293 to 353 K and for concentrations between 0.1 and 0.4 mol l −1 .…”

Determination of solutions density by the dilatometric titration method

“…A disadvantage of the areometric method, which is the most simple in application, is its low accuracy (about 10 -3 g cm -3 ); the bottle method is characterized by a slightly greater accuracy, but it is noticeably more difficult in execution. The hydrostatic balance and the magnetic float methods [1] are recognized as the most convenient and accurate methods, which are used, in particular, in various automatic densimeters [2,3]. At the same time all the specified methods are methods of "separate tests," i.e.…”