The density of gaseous ethane and of fluid methyl chloride, and the vapor pressure of methyl chloride

The speed of sound and derived thermodynamic properties of ethane at temperatures between 220 K and 450 K and pressures up to 10.5 MPa

“…The datum of In figures 5 and 6, we compare the derived virial coefficients with directly measured values taken from the literature. The present second virial coefficients are in good agreement with those of Douslin and Harrison, (25) Michels et al (26) and Mansoorian et al (27) The near agreement with Douslin and Harrison over the full temperature range of their measurements (273.15 E T/K E 623.15) is particularly encouraging and demonstrates the reliability of the model as a means of extrapolation. We also note good agreement with the ''square-well'' formula derived by Boyes (19) from his second acoustic virial coefficients.…”

“…(25) Finally, we note that the compression factors of Mansoorian et al, (27) which have a claimed uncertainty of 0.033 per cent and extend up to r n = 1.5 mol·dm −3 , all lie within 20.04 per cent of the present results. As the initial conditions for our integrations came from a different source, this agreement is encouraging.…”

“…The present compression factors are compared with those of Douslin and Harrison (25) and Mansoorian et al (27) in figures 7 and 8. First, it should be noted that the integration procedure reproduced the smooth polynomial approximations Z j used in the initial conditions almost exactly so that the deviations showed in figure 7 at T = 298.15 K and T = 303.15 K corresponded to the scatter of the pr n T data.…”

Optimum mixture compositions for measurement of cross virial coefficients

“…For adsorption examples (2 = polar, adsorbing gas; 1 = nonpolar gas), the cubic behavior (Figure 1) is close to the observation (Mansoorian et al, 1981) that the dominant adsorption errors for an equimolar binary mixture are roughly (I/,) of those of the pure polar compound. The results of several numerical examples are as follows.…”

Random and systematic errors in thermophysical property measurements

“…When the precision (reproducibility) of each data set is very high, then the disagreement can be ascribed to important systematic errors in either one data set or both. An example is the vapor pressure of methyl chloride from 3 13 to 408 K (Mansoorian et al, 1981) where careful, precise measurements of f 1 kPa from two laboratories provided a systematic bias of about 30 kPa that was resolved only later when measurements from a third laboratory were published (Holldorff and Knapp, 1988).…”