Experimental validation of the relationship between internal energy and state of ideal gas

摘要

The statement that the internal energy of ideal gas depends only on its temperature but not its volume and pressure in the free expansion process has been a topic of continuous argument in academic community. We report experimental validation of the relationship between internal energy of ideal gas and each state function. The relative internal energy in different pressure systems was determined, resulting the regression equation in P, U coordinate system. The continued equality was derived by comparing the regression equation and the definition of heat capacity at constant volume. The relationship of internal energy with volume and quantity was further derived through the state transformation method. Meanwhile, Meyer’s equation and the equation of enthalpy were also derived. Therefore, the internal energy of ideal gas has interrelationship with each state function; and a close relationship between the continued equality derived herein and current theory of ideal gas was well established.