Virial Coefficients of Three Organic Sulphides

1962 ◽  
Vol 15 (2) ◽  
pp. 190 ◽  
Author(s):  
GA Bottomley ◽  
IH Coopes
Keyword(s):  
Room Temperature ◽  
Virial Coefficients ◽  
Thermodynamic Method ◽  
Dimethyl Sulphide ◽  
Methyl Ethyl ◽  
Second Virial Coefficients ◽  
Specific Heats ◽  
Two Temperatures ◽  
Latent Heats

The second virial coefficients at two temperatures somewhat above room temperature have been determined for the three substances dimethyl sulphide, diethyl sulphide, and methyl ethyl sulphide by e precision differential compressibility method, and the numerical values compared with determinations by the indirect thermodynamic method using vapour specific heats and latent heats of evaporation.

An apparatus for the measurement of the second virial coefficients of vapours; the second virial coefficients of some n -alkanes and of some mixtures of n -alkanes

1962 ◽  
Vol 267 (1331) ◽  
pp. 478-500 ◽  
Keyword(s):  
Chain Length ◽  
Simple Formula ◽  
Room Temperature ◽  
Virial Coefficients ◽  
Direct Methods ◽  
Differential Method ◽  
Corresponding States ◽  
Second Virial Coefficients ◽  
Slight Extension

An apparatus for the measurement of the second virial coefficients of vapours is described. It is designed so that a sample of the gas under investigation can be compared directly with a reference gas (nitrogen). This differential method has practical advantages over direct methods. The apparatus has been used to measure the second virial coefficients of the series of n-alkanes from propane to n-octane from near room temperature to about 140 °C. The results form a family showing deviations from the principle of corresponding states which increase regularly with increasing chain length. A simple formula based on the principle of corresponding states has been found to fit not only the present measurements, but also, previous measurements by other workers at higher temperatures on these substances, and also previous measurements on methane and on ethane. Measurements have also been made on equimolar mixtures of propane + n -heptane and of propane + n -octane. The results are in much better agreement with a slight extension of a rule of Guggenheim & McGlashan (1951) based on the principle of corresponding states than with the rule of Lewis & Randall (1923)-

The Bender Equation of State and Virial Coefficients

2000 ◽  
Vol 65 (9) ◽  
pp. 1464-1470 ◽  
Author(s):  
Anatol Malijevský ◽  
Tomáš Hujo
Keyword(s):  
Equation Of State ◽  
Virial Coefficient ◽  
Virial Coefficients ◽  
Low Density ◽  
Second Virial Coefficients ◽  
The Third ◽  
Temperature Dependences ◽  
Experimental Values

The second and third virial coefficients calculated from the Bender equation of state (BEOS) are tested against experimental virial coefficient data. It is shown that the temperature dependences of the second and third virial coefficients as predicted by the BEOS are sufficiently accurate. We conclude that experimental second virial coefficients should be used to determine independently five of twenty constants of the Bender equation. This would improve the performance of the equation in a region of low-density gas, and also suppress correlations among the BEOS constants, which is even more important. The third virial coefficients cannot be used for the same purpose because of large uncertainties in their experimental values.

scholarly journals On the measurement of the ratio of the specific heats using small volumes of gas.—The ratios of the specific heat of air and of hydrogen at atmospheric pressure and a temperatures between 20°C. and —183°C

1925 ◽  
Vol 107 (743) ◽  
pp. 510-543 ◽  
Keyword(s):  
Systematic Error ◽  
Low Temperatures ◽  
Room Temperature ◽  
Expansion Chamber ◽  
Small Vessels ◽  
Specific Heats ◽  
Large Expansion ◽  
Before And After ◽  
The One ◽  
Chamber Capacity

Introduction .—In nearly all the previous determinations of the ratio of the specific heats of gases, from measurements of the pressures and temperature before and after an adiabatic expansion, large expansion chambers of fror 50 to 130 litres capacity have been used. Professor Callendar first suggests the use of smaller vessels, and in 1914, Mercer (‘Proc. Phys. Soc.,’ vol. 26 p. 155) made some measurements with several gases, but at room temperature only, using volumes of about 300 and 2000 c. c. respectively. He obtained values which indicated that small vessels could be used, and that, with proper corrections, a considerable degree of accuracy might be obtained. The one other experimenter who has used a small expansion chamber, capacity about 1 litre, is M. C. Shields (‘Phys. Rev.,’ 1917), who measured this ratio for air and for hydrogen at room temperature, about 18° C., and its value for hydroger at — 190° C. The chief advantage gained by the use of large expansion chambers is that no correction, or at the most, a very small one, has to be made for any systematic error due to the size of the containing vessels, but it is clear that, in the determinations of the ratio of the specific heats of gases at low temperatures, the use of small vessels becomes a practical necessity in order that uniform and steady temperature conditions may be obtained. Owing, however, to the presence of a systematic error depending upon the dimensions of the expansion chamber, the magnitude of which had not been definitely settled by experiment, the following work was undertaken with the object of investigating the method more fully, especially with regard to it? applicability to the determination of this ratio at low temperatures.

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