3. Ideal and Real Gasses
The ideal gas EOS is the simplest model to relate the pressure, temperature, and specific volume of a gas. It can be used for thermodynamic analysis if the compressibiliy factor of a gas at a given condition approaches one, or the gas behaves like an “ideal” gas. It is important to note that, despite its simplicity, the ideal gas EOS cannot be used in all conditions. Its suitability at a given state must be verified.
A real gas doesn’t obey the ideal gas EOS at a given state. For a real gas, the compressibility factor can be incorporated to improve the accuracy of the prediction of the [latex]P - v - T[/latex] relation. The compressibility factor of a gas may be obtained from the generalized compressibility chart.