General Properties of Gaseous Systems

Abstract

This chapter deals with the general properties of gases starting from their isothermal behavior and the definition of the virial coefficients. The Joule–Thomson experiment (throttling experiment) is discussed together with the subsequent calorimetric measurements which prove the proportionality of the first virial coefficient to the absolute temperature T. The latter fact allows us to have a further tool for defining the absolute scale once an arbitrary value for T at one reference state is chosen. The Joule–Thomson coefficient and the inversion curve are defined and the problem of gases liquefaction is shortly outlined. The expression of the chemical potential for dilute gases is also shown. The heat capacities of gases are widely discussed starting from the theorem of energy equipartition.