The discussion centers on the mathematical representation of real gas behavior, specifically the deviation from ideal gas laws. The correct equation for the curve depicting this deviation involves the compressibility factor Z, which is defined as $$\frac{PV}{RT}$$ where V is the molar volume. The Principle of Corresponding States indicates that Z depends on reduced pressure, reduced temperature, and the acentric factor, which varies by gas. Additionally, changing the x-axis to volume would alter the graph's representation, emphasizing the relationship between these variables. Resources such as P.W. Atkins' physical chemistry book can provide further insights into these concepts.
