21. The specific heats are particularly useful for thermodynamic calculations involving the ideal gas model. 22. Much later the ideal gas law was formulated in 1834. 23. Equipartition was used above to derive the classical ideal gas law from Newtonian mechanics. 24. The model of an ideal gas , however, does not describe or allow phase transitions. 25. Erwin Schr�dinger applied this to derive the thermodynamic properties of a semiclassical ideal gas . 26. Such systems are known as " ideal gas thermometers ". 27. This implies that the pressure of an ideal gas has a purely entropic origin. 28. Plugging in the radiation pressure, instead of the ideal gas pressure used above, yields 29. Thus, in an isothermal process the internal energy of an ideal gas is constant. 30. You could change the variables in the Ideal gas law.
