On the Ideal Gas and the Equation of State of Real Gases

When a gas is defined as the limiting one among real gases having zero radius of molecule, it was proved theoretically and by experimental data of the Joule-Thomson effect in various real gases that such a gas satisfied the whole well-known thermodynamic properties of the ideal gas. Thermodynamic properties of real gases at very low pressures were shown not to coincide with those of the ideal gas except with reference to the equation of state and specific heat capacity etc. and relations between real gases and the ideal gas were discussed. An empirical equation of state of real gases was reasonably shown to have to be of the virial expansion type.