Isotherms in the Critical Regions of Carbon Dioxide and Sulfur Hexafluoride

Publisher Website
Google Scholar
Abstract
The p‐v isotherms of carbon dioxide and sulfur hexafluoride have been measured in their critical regions at 0.02°C temperature intervals while the gases were observed and photographed. It was found that the liquid‐vapor boundary curve has a nearly flat top; this renders the classical van der Waals picture of the critical region inadequate. Some slight evidence was found for an anomalous critical region as predicted by Mayer, but this region could be only 0.04°C high for sulfur hexafluoride and less than 0.02°C high for carbon dioxide. It was found that constant pressure is rapidly achieved in the critical region, but that constancy of fluid structure requires five or more hours. The results of these experiments agree well with those of MacCormack and Schneider for sulfur hexafluoride and those of Michels for carbon dioxide. The influence of gravity upon critical phenomena was found to be large. A brief discussion of its effects and corrections to be made on account of it are given.

This publication has 14 references indexed in Scilit: