Abstract: The visualization of physical chemistry formulas significantly enhances students’ comprehension and mastery of relevant concepts, while the application of appropriate data processing software simplifies the visualization process. This study employs nitrogen gas as an example, utilizing the Van der Waals equation and Joule-Thomson coefficient formula to construct three-dimensional representations of pV-(p,T), T-(p,T₀), and μ_J-T-(p,T) relationships. These visualizations facilitate more intuitive instruction regarding the throttling expansion effects in real gases. Furthermore, through the μ_J-T-(p,T) and V-(p,T) plots, we demonstrate both the gas liquefaction process and engineering methods for calculating ΔH, ΔS, and ΔG of Van der Waals gases under isothermal conditions.

Key words: Throttling expansion, Van der Waals equation of state, Joule-Thomson coefficient, Enthalpy, Entropy, Gibbs free energy