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In another thread, DH and I have been discussing the definition of an ideal gas. DH, who appears to be a physicist, seems to use a definition different from that which we engineers use. I am soliciting responses from both physicists and engineers as to their understanding of the term "ideal gas." I would like to determine whether there really is a difference or not. To get the ball rolling, here is my understanding, as an engineer, of what an ideal gas is:
The term "ideal gas" describes the limiting behavior of a real gas in the limit of low pressures. As such it has the following characteristics:
1. Its PVT behavior is described by PV=nRT
2. Its internal energy and enthalpy are functions only of temperature.
3. Its Cp and Cv can vary with temperature (although for monatomic gases, this variation is negligible).
This definition is in agreement with that given in engineering treatises by Smith and Van Ness (Introduction to Chemical Engineering Thermodynamics), Hougan and Watson, Perry's (Chemical Engineers' Handbook), and Bird, Stewart, and Lightfoot (Transport Phenomena).
I'm hoping that people with engineering backgrounds in particular, like rude man, SteamKing, and maybe, Studiot will respond to this thread and voice their understandings.
Chet
The term "ideal gas" describes the limiting behavior of a real gas in the limit of low pressures. As such it has the following characteristics:
1. Its PVT behavior is described by PV=nRT
2. Its internal energy and enthalpy are functions only of temperature.
3. Its Cp and Cv can vary with temperature (although for monatomic gases, this variation is negligible).
This definition is in agreement with that given in engineering treatises by Smith and Van Ness (Introduction to Chemical Engineering Thermodynamics), Hougan and Watson, Perry's (Chemical Engineers' Handbook), and Bird, Stewart, and Lightfoot (Transport Phenomena).
I'm hoping that people with engineering backgrounds in particular, like rude man, SteamKing, and maybe, Studiot will respond to this thread and voice their understandings.
Chet